PBMD Immutep Limited

RISK FACTORS

You should consider carefully the risks described below and discussed under the section captioned “Risk Factors” contained in our annual report on Form 20-F for the fiscal year ended June 30, 2016, which is incorporated by reference in this prospectus supplement and the accompanying prospectus in its entirety, together with other information in this prospectus supplement, the accompanying prospectus and the information and documents incorporated by reference in this prospectus supplement and the accompanying prospectus, and any free writing prospectus that we have authorized for use in connection with this offering before you make a decision to invest in the ADSs. If any of the following events actually occur, our business, operating results, prospects or financial condition could be materially and adversely affected. This could cause the trading price of the ADSs to decline and you may lose all or part of your investment. The risks described below are not the only ones that we face. Additional risks not presently known to us or that we currently deem immaterial may also affect our business operations.

Risks Relating to this Offering

If you purchase ADSs sold in this offering, you will experience immediate and substantial dilution in the net tangible book value of the ordinary shares represented by the ADSs. In addition, we may issue additional equity or convertible debt securities in the future, which may result in additional dilution to investors.

The offering price per ADS in this offering is considerably more than the net tangible book value per ADS of our outstanding ADSs. As a result, investors purchasing ADSs in this offering will pay a price per ADS that substantially exceeds the value of our tangible assets after subtracting liabilities. Investors will incur immediate dilution of $0.0139 per ordinary share (or $1.3926 per ADS), based on the public offering price of $1.90 per ADS and the net tangible book value as of March 31, 2017. For a more detailed discussion of the foregoing, see the section entitled “Dilution” below. To the extent outstanding derivative securities or the Purchase Warrants being offered by us in the concurrent private placement are exercised for, or converted into, ordinary shares or ADSs representing ordinary shares, there will be further dilution to new investors. In addition, to the extent we need to raise additional capital in the future and we issue additional equity or convertible debt securities, our then existing ADS holders may experience dilution and the new securities may have rights senior to those of the ADSs we are offering in this offering.

Our management team may invest or spend the proceeds of this offering in ways with which you may not agree or in ways which may not yield a return.

Our management will have broad discretion over the use of proceeds from this offering. We intend to use the net proceeds from this offering to continue of our ongoing clinical development of IMP321 (e.g., the AIPAC and TACTI-mel studies), to continue our preclinical research on IMP761 and for other general corporate purposes. We also may use a portion of the net proceeds to acquire or invest in businesses, products and technologies that we view as complementary to our own. Our management will have considerable discretion in the application of the net proceeds, and you will not have the opportunity, as part of your investment decision, to assess whether the proceeds are being used appropriately. The net proceeds may be used for corporate purposes that do not increase our operating results or enhance the value of the ADSs.

Risks Relating to Our Securities, including an Investment in the ADSs

Our ADS holders are not shareholders and do not have shareholder rights.

The Bank of New York Mellon, as depositary, registers and delivers the ADSs. ADS holders will not be treated as shareholders and do not have the rights of shareholders. The depositary will be the holder of the shares underlying the ADSs. Holders of the ADSs will have ADS holder rights. A deposit agreement among us, the depositary and the ADS holders, and the beneficial owners of ADSs, sets out ADS holder rights as well as the rights and obligations of the depositary. New York law governs the deposit agreement and the ADSs. Our shareholders have shareholder rights. Australian law and our constitution govern shareholder rights. For a

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description of ADS holder rights and shareholders’ rights, see our Annual Report on Form 20-F for the year ended June 30, 2016, which is incorporated by reference in this prospectus supplement. ADS holders do not have the same voting rights as our shareholders. Shareholders are entitled to our notices of general meetings and to attend and vote at our general meetings of shareholders. At a general meeting, every shareholder present (in person or by proxy, attorney or representative) and entitled to vote has one vote on a show of hands. Every shareholder present (in person or by proxy, attorney or representative) and entitled to vote has one vote per fully paid ordinary share on a poll. This is subject to any other rights or restrictions which may be attached to any shares. ADS holders may exercise voting rights with respect to the underlying ordinary shares only in accordance with the provisions of the deposit agreement. Under the deposit agreement, ADS holders vote by giving voting instructions to the depositary. Upon receipt of instructions, the depositary will try to vote in accordance with those instructions. Otherwise, ADS holders will not be able to vote unless they withdraw the ordinary shares underlying their ADSs. ADS holders may not learn of ordinary shareholders’ meetings in time to instruct the depositary or withdraw underlying ordinary shares. If we ask for ADS holders’ instructions, the depositary will notify ADS holders of the upcoming vote and arrange to deliver our voting materials and form of notice to them. The depositary will try, as far as practical, subject to Australian law and the provisions of the depositary agreement, to vote the shares as ADS holders instruct. The depositary will not vote or attempt to exercise the right to vote other than in accordance with the instructions of the ADS holders. We cannot assure ADS holders that they will receive the voting materials in time to ensure that they can instruct the depositary to vote their shares. This means that there is a risk that ADS holders may not be able to exercise voting rights and there may be nothing they can do if their shares are not voted as they requested.

ADS holders do not have the same rights to receive dividends or other distributions as our shareholders.

Subject to any special rights or restrictions attached to a share, the directors may determine that a dividend will be payable on a share and fix the amount, the time for payment and the method for payment (although we have never declared or paid any cash dividends on our ordinary stock and we do not anticipate paying any cash dividends in the foreseeable future). Dividends may be paid on shares of one class but not another and at different rates for different classes. Dividends and other distributions payable to our shareholders with respect to our ordinary shares generally will be payable directly to them. Any dividends or distributions payable with respect to ordinary shares will be paid to the depositary, which has agreed to pay to ADS holders the cash dividends or other distributions it or the custodian receives on shares or other deposited securities, after deducting its fees and expenses. ADS holders will receive these distributions in proportion to the number of shares their ADSs represent. In addition, there may be certain circumstances in which the depositary may not pay to ADS holders amounts distributed by us as a dividend or distribution.

There are circumstances where it may be unlawful or impractical to make distributions to the holders of the ADSs.

The deposit agreement with the depositary generally requires the depositary to convert foreign currency it receives in respect of deposited securities into U.S. dollars and distribute the U.S. dollars to ADS holders, provided the depositary can do so on a reasonable basis. If it does not convert foreign currency, the depositary may distribute the foreign currency only to those ADS holders to whom it is possible to do so. If a distribution is payable by us in Australian dollars, the depositary will hold the foreign currency it cannot convert for the account of the ADS holders who have not been paid. It will not invest the foreign currency and it will not be liable for any interest. If the exchange rates fluctuate during a time when the depositary cannot convert the foreign currency, ADS holders may lose some of the value of the distribution. The depositary is not responsible if it decides that it is unlawful or impractical to make a distribution available to any ADS holders. This means that ADS holders may not receive the distributions we make on our shares or any value for them if it is illegal or impractical for us to make them available.

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NASDAQ may delist the ADSs from trading on the exchange which could limit investors’ ability to make transactions in the ADSs and subject us to additional trading restrictions.

We may in the future fail to comply with the NASDAQ Global Market regulations and listing requirements as to minimum stockholders’ equity, minimum market value, minimum total assets and revenue, minimum bid price, minimum public float and other requirements (which we refer to as the NASDAQ Listing Requirements), and as a result NASDAQ may initiate procedures to delist our ordinary shares from the NASDAQ Global Market.

During the 12-month period preceding March 31, 2017, the ADSs traded in a range from $0.51 to $3.26 per ADS, and the longest period below $1.00 was for 129 trading days from January 14, 2016 through March 9, 2017, inclusive. Under NASDAQ’s Marketplace Rule 5450(a)(1) (which we refer to as the Minimum Bid Price Rule), any company whose shares have a closing bid price less than $1.00 for 30 consecutive trading days may be subject to a delisting proceeding by NASDAQ for failure to meet the Minimum Bid Price Rule. On March 4, 2016, we announced that we received a deficiency letter from NASDAQ that we were not in compliance with NASDAQ Listing Rule 5450(a)(1) for failing to have a bid price for one ADS of at least $1.00 per share for the prior thirty trading days. In addition, after regaining compliance, on August 10, 2016, we announced that we received another deficiency letter from NASDAQ advising that we were again not in compliance with Minimum Bid Price Rule. Although we remedied this noncompliance in part through changing the ordinary share-to-ADS ratio from 30:1 to 100:1 in December 2016, there can be no assurance that we will again not fall below the minimum bid price required by the NASDAQ Listing Requirements nor can there be any assurance we will not be required to further change our ordinary share-to-ADS ratio in response thereto.

If we fail to meet the continued listing criteria under the Minimum Bid Price Rule or any of the NASDAQ Listing Requirements, the ADSs may be delisted from trading on the Nasdaq Global Market.

Delisting from the NASDAQ Global Market could have an adverse effect on our business and on the trading of the ADSs. If a delisting of the ADSs were to occur, such shares may trade in the over-the-counter market such as on the OTC Bulletin Board or on the “pink sheets.” The over-the-counter market is generally considered to be a less efficient market, and this could diminish investors’ interest in the ADSs as well as significantly impact the price and liquidity of the ADSs. Any such delisting may also severely complicate trading of the ADSs by our holders, or prevent them from re-selling their ADSs at/or above the price they paid. Furthermore, our relatively low trading volume on the NASDAQ Global Market may make it difficult for shareholders to trade ADSs or initiate any other transactions. Delisting may also make it more difficult for us to issue additional securities or secure additional financing.

Our stock price is volatile and could decline significantly.

The market price of our ordinary shares historically has been, and we expect will continue to be, subject to significant fluctuations over short periods of time. These fluctuations may be due to factors specific to us, to changes in analysts’ recommendations and earnings estimates, to arbitrage between our ASX listed shares and the ADSs, to changes in exchange rates, or to factors affecting the biopharmaceutical industry or the securities markets in general. Market fluctuations, as well as general political and economic conditions, such as a recession, interest rate or currency fluctuations, could adversely affect the market price of our securities.

For example, during the last two fiscal years, the market price for our ordinary shares on the ASX has ranged from as low as A$0.02 to a high of A$0.19. During the 12 months preceding the date of this prospectus supplement, the market price of our ordinary shares on the ASX has ranged from a low of A$0.03 to a high of A$0.05. We may experience a material decline in the market price of our shares, regardless of our operating performance. Therefore, a holder of our ordinary shares or ADSs may not be able to sell those ordinary shares or ADSs at or above the price paid by such holder for such shares or ADSs. Price declines in our ordinary shares or ADSs could result from a variety of factors, including many outside our control. These factors include:

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Our ordinary shares may be considered a “penny stock” under SEC regulations which could adversely affect the willingness of investors to hold the ADSs.

The SEC has adopted regulations which generally define “penny stock” to be an equity security that has a market price of less than $5.00 per share, subject to specific exemptions. During the fiscal year ended June 30, 2016, our ordinary shares traded on the ASX from a low of A$0.04 to a high of A$0.09 per share, and during the nine-month period ended March 31, 2017, our ordinary shares traded on the ASX from a low of A$0.03 to a high of A$0.04 per share. Penny stock rules impose additional sales practice requirements on broker-dealers who sell to persons other than established customers and “accredited investors.” The term “accredited investor” refers generally to institutions with assets in excess of $5,000,000 or individuals with a net worth in excess of $1,000,000 or annual income exceeding $200,000 or $300,000 jointly with their spouse in each of the prior two years.

The penny stock rules require a broker-dealer, prior to a transaction in a penny stock not otherwise exempt from the rules, to deliver a standardized risk disclosure document in a form prepared by the SEC, which provides (a) contains a description of the nature and level of risk in the market for penny stocks in both public offerings and secondary trading; (b) contains a description of the broker’s or dealer’s duties to the customer and of the rights and remedies available to the customer with respect to a violation of such duties or other requirements of the securities laws; (c) contains a brief, clear, narrative description of a dealer market, including bid and ask prices for penny stocks and the significance of the spread between the bid and ask price; (d) contains a toll-free telephone number for inquiries on disciplinary actions; (e) defines significant terms in the disclosure document or in the conduct of trading in penny stocks; and (f) contains such other information and is in such form, including language, type size and format, as the SEC shall require by rule or regulation.

The broker-dealer also must provide, prior to effecting any transaction in a penny stock, the customer with (a) bid and offer quotations for the penny stock; (b) the compensation of the broker-dealer and its salesperson in the transaction; (c) the number of shares to which such bid and ask prices apply, or other comparable information relating to the depth and liquidity of the market for such stock; and (d) a monthly account statement showing the market value of each penny stock held in the customer’s account.

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In addition, the penny stock rules require that prior to a transaction in a penny stock not otherwise exempt from those rules, the broker-dealer must make a special written determination that the penny stock is a suitable investment for the purchaser and receive the purchaser’s written acknowledgment of the receipt of a risk disclosure statement, a written agreement as to transactions involving penny stocks, and a signed and dated copy of a written suitability statement.

These disclosure requirements may have the effect of reducing the trading activity for our common stock. Therefore, stockholders may have difficulty selling our securities.

In addition, the low trading price of our ordinary shares may adversely affect the willingness of investors to hold the ADSs.

We may be a passive foreign investment company (PFIC) which would subject our U.S. investors to adverse tax rules.

Holders of ADSs who are U.S. residents face income tax risks. There is a substantial risk that we are currently a passive foreign investment company, or PFIC, which could result in a reduction in the after-tax return to a “U.S. Holder” of the ADSs and reduce the value of the ADSs. For U.S. federal income tax purposes, we will be classified as a PFIC for any taxable year in which (i) 75% or more of our gross income is passive income, or (ii) at least 50% of the average value of all of our assets for the taxable year produce or are held for the production of passive income. For this purpose, cash is considered to be an asset that produces passive income.

The determination of whether we are a PFIC is made on an annual basis and depends on the composition of our income and the value of our assets. Therefore, it is possible that we could be a PFIC in the current year as well as in future years. If we are classified as a PFIC in any year that a U.S. Holder owns ADSs, the U.S. Holder will generally continue to be treated as holding ADSs of a PFIC in all subsequent years, notwithstanding that we are not classified as a PFIC in a subsequent year. Dividends received by the U.S. Holder and gains realized from the sale of the ADSs would be taxed as ordinary income and subject to an interest charge. We urge U.S. investors to consult their own tax advisors about the application of the PFIC rules and certain elections that may help to minimize adverse U.S. federal income tax consequences in their particular circumstances.

We have never paid a dividend and we do not intend to pay dividends in the foreseeable future which means that holders of shares and ADSs may not receive any return on their investment from dividends.

To date, we have not declared or paid any cash dividends on our ordinary shares and currently intend to retain any future earnings for funding growth. We do not anticipate paying any dividends in the foreseeable future. Dividends may only be paid out of our profits. Payment of cash dividends, if any, in the future will be at the discretion of our board of directors. Our holders of shares and ADSs may not receive any return on their investment from dividends. The success of your investment will likely depend entirely upon any future appreciation of the market price of our ordinary shares, which is uncertain and unpredictable. There is no guarantee that our ordinary shares will appreciate in value or even maintain the price at which you purchased your ordinary shares.

Currency fluctuations may adversely affect the price of the ADSs relative to the price of our ordinary shares.

The price of our ordinary shares is quoted in Australian dollars and the price of the ADSs will be quoted in U.S. dollars. Movements in the Australian dollar/U.S. dollar exchange rate may adversely affect the U.S. dollar price of the ADSs and the U.S. dollar equivalent of the price of our ordinary shares. In the last five years, the Australian dollar has as a general trend depreciated against the U.S. dollar. Any continuation of this trend may adversely affect the U.S. dollar price of the ADSs and the U.S. dollar equivalent of the price of our ordinary shares, even if the price of our ordinary shares in Australian dollars increases or remains unchanged. However, this trend may not continue and may be reversed. If the Australian dollar weakens against the U.S. dollar, the U.S. dollar price of the ADSs could decline, even if the price of our ordinary shares in Australian dollars increases or remains unchanged.

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The requirements of being a public company may strain our resources and divert management’s attention and if we are unable to maintain effective internal control over financial reporting in the future, the accuracy and timeliness of our financial reporting may be adversely affected.

As a publicly-traded company, we are subject to the reporting requirements of the U.S. Securities Exchange Act of 1934, as amended (the Exchange Act), the Sarbanes-Oxley Act, the Dodd-Frank Act, the listing requirements of the NASDAQ Global Market and other applicable securities rules and regulations. Compliance with these rules and regulations will increase our legal and financial compliance costs, make some activities more difficult, time-consuming or costly and increase demand on our systems and resources. The Exchange Act requires, among other things, that we file certain reports with respect to our business and results of operations. The Sarbanes-Oxley Act requires, among other things, that we maintain effective disclosure controls and procedures and internal control over financial reporting. In order to maintain and, if required, improve our disclosure controls and procedures and internal control over financial reporting to meet this standard, significant resources and management oversight are required. As a result, management’s attention may be diverted from other business concerns, which could adversely affect our business and results of operations.

The Sarbanes-Oxley Act requires, among other things, that we assess the effectiveness of our internal control over financial reporting annually and disclosure controls and procedures quarterly. In particular, beginning with fiscal year ended on June 30, 2013, we have performed system and process evaluation and testing of our internal control over financial reporting to allow our management to report on the effectiveness of our internal control over financial reporting, as required by Section 404 of the Sarbanes-Oxley Act. We have in prior fiscal years identified material weaknesses that have been remediated. If we identify material weaknesses in future periods or we are not able to comply with the requirements of Section 404 in a timely manner, our reported financial results could be restated, we could be subject to investigations or sanctions by regulatory authorities, which would require additional financial and management resources, and the market price of our stock could decline.

Our ordinary shares are listed and traded on the ASX and NASDAQ. Price levels for our ordinary shares could fluctuate significantly on either market, independent of our share price on the other market. Investors could seek to sell or buy our shares to take advantage of any price differences between the three markets through a practice referred to as arbitrage. Any arbitrage activity could create unexpected volatility in our share prices on either exchange and the volumes of shares available for trading on either exchange. In addition, holders of shares in either jurisdiction will not be immediately able to transfer such shares for trading on the other markets without effecting necessary procedures with our transfer agent. This could result in time delays and additional cost for our shareholders. Further, if we are unable to continue to meet the regulatory requirements for listing on the ASX and NASDAQ, we may lose our listing on any of these exchanges, which could impair the liquidity of our shares.

Risks Relating to Our Business

We have a history of operating losses and may not achieve or maintain profitability in the future.

We are at an early stage in the development of pharmaceutical products and their success is therefore uncertain. We focus on the development of immunotherapeutic products for the treatment of cancer. We, and our partners, have three products under development-IMP321, IMP701, IMP731 and IMP761, all of which are directed to lymphocyte activation gene 3, or LAG-3, a gene linked to the regulation of T cells in immune responses. In prior years, our business was focused on the development of CVac™, an autologous dendritic cell cancer vaccine. However, in February 2015, we suspended the development of CVac™ during its Phase II clinical trials in favor of focusing on biologicals like IMP321, which offer greater commercial potential based on cost of goods alone. While the decision to consolidate the CVac™ clinical trial program and to cease the patient recruitment has led to a significant decrease of costs, the clinical trial program of IMP321 will generate new expenses, especially as two clinical trials have been started (AIPAC and TACTI-mel). There can also be no guarantee that IMP321 will successfully be partnered or that any of our product candidates or know how, whether partnered or not, will ever generate future revenues. At this point, none of our products generate significant revenue.

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For the nine-month period ended March 31, 2016 and 2017, we had a net loss of approximately $58.5 million and $6.3 million, respectively. The significant decrease in net loss for the nine-month period ended March 31, 2017 was primarily attributable to a share based payment to a strategic investor of $47.5 million incurred in the issue of a convertible note and warrants to Ridgeback Capital Investments in the nine-month period to March 31, 2016. In addition, our total other income increased A$1.8 million to A$3.4 million for the nine-month period ended March 31, 2017 from A$1.6 million for the nine-month period ended March 31, 2016. The increase was primarily attributable to A$1.7 million higher cash tax rebates from the French and Australian governments recognized in the third quarter ended March 31, 2017 compared to A$0.0 million for the three-month period to March 31, 2016. We will continue to incur losses from operations and expect the costs of drug development to increase in the future as more patients are recruited to the planned trials. In particular, we will continue to incur significant losses in carrying out clinical trials of IMP321 necessary for regulatory approval and ongoing research in terms of immunotherapy product candidates. Because of the numerous risks and uncertainties associated with the development, manufacturing, sales and marketing of therapeutic products, we may experience larger than expected future losses and may never become profitable.

There is a substantial risk that we, or our development partners, may not be able to complete the development of our current product candidates or develop other pharmaceutical products. It is possible that none of them will be successfully commercialized, which would prevent us from ever achieving profitability.

We have no medicinal products approved for commercial sale and no source of material revenue.

Currently, we have no products approved for commercial sale and to date have not generated material revenue from product sales. We are largely dependent on the success of our product candidates, especially the LAG-3 related ones.

The LAG 3 product candidates were acquired by us through the acquisition of the French privately owned and venture capital backed company Immutep SA, a biopharmaceutical company in the rapidly growing field of Immuno-Oncology in December 2014. This acquisition significantly expanded our clinical development product portfolio to other categories of immunotherapies. It has also provided Prima with partnerships with several of the world’s largest pharmaceutical companies.

We have several LAG-3 product candidates. The most advanced of is IMP321. IMP321 is a recombinant protein typically used in conjunction with chemotherapy to amplify a patient’s immune response. The development and manufacturing of IMP321 is being conducted in conjunction with Eddingpharm.

Another LAG-3 product candidate is IMP701, an antagonist antibody that acts to stimulate T cell proliferation in cancer patients. IMP701 has been licensed to CoStim (Novartis), which is solely responsible for its development and manufacturing.

A third LAG-3 product candidate is IMP731, a depleting antibody that removes T cells involved in autoimmunity. IMP731 has been licensed to GlaxoSmithKline, or GSK, which is solely responsible for its development and manufacturing.

Finally, in January 2017 we announced we conducted research on a new early stage product candidate, a humanized IgG4 monoclonal antibody known as IMP761.

In addition to these products Immutep also has a dedicated R&D laboratory outside Paris with other research candidates in development. Immutep also currently generates modest revenues from sales of LAG-3 research reagents.

There can be no assurance that our ability to develop any product candidate, will be successful or our ability to obtain the necessary regulatory approvals with respect to any of the foregoing will be successful.

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We anticipate that as the costs related to the clinical trials for IMP321 will increase, we will require additional funds to achieve our long-term goals of commercialization and further development of IMP321 and other product candidates. In addition, we will require funds to pursue regulatory applications, defend intellectual property rights, increase contracted manufacturing capacity, potentially develop marketing and sales capability and fund operating expenses. We intend to seek such additional funding through public or private financings and/or through licensing of our assets or other arrangements with corporate partners. However, such financing, licensing opportunities or other arrangements may not be available from any sources on acceptable terms, or at all. Any shortfall in funding could result in us having to curtail or cease our operations including research and development activities, thereby harming our business, financial condition and results of operations.

Our ability to generate product revenue depends on a number of factors, including our ability to:

In addition, because of the numerous risks and uncertainties associated with product candidate development, we are unable to predict the timing or amount of increased expenses, or when, or if, we will be able to achieve or maintain profitability. Our expenses could increase beyond current expectations if the applicable regulatory authorities require further studies in addition to those currently anticipated and even if our product candidates are approved for commercial sale, we anticipate incurring significant costs associated with the commercial launch of such products and there can be no guarantee that we will ever generate significant revenues.

We will require additional financing and may be unable to raise sufficient capital, which could have a material impact on our research and development programs or commercialization of our products or product candidates.

We have historically devoted most of our financial resources to research and development, including pre-clinical and clinical development activities. To date, we have financed a significant amount of our operations through public and private financings. The amount of our future net losses will depend, in part, on the rate of our future expenditures and our ability to obtain funding through equity or debt financings or strategic collaborations. The amount of such future net losses, as well as the possibility of future profitability, will also depend on our success in developing and commercializing products that generate significant revenue. Our failure to become and remain profitable would depress the value of our ordinary shares or ADSs and could impair our ability to raise capital, expand our business, maintain our research and development efforts, diversify our product offerings or even continue our operations.

We anticipate that our expenses will increase substantially for the foreseeable future if, and as, we:

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Until our products become commercially available, we will need to obtain additional funding in connection with the further development of our products and product candidates. Our ability to obtain additional financing will be subject to a number of factors, including market conditions, our operating performance and investor sentiment. As such, additional financing may not be available to us when needed, on acceptable terms, or at all. If we are unable to raise capital when needed or on attractive terms, we could be forced to delay, reduce or eliminate our research and development programs or any future commercialization efforts or obtain funds by entering agreements on unattractive terms. Our resource allocation decisions and the elimination of development programs may result in the failure to capitalize on profitable market opportunities. Furthermore, any additional equity fundraising in the capital markets may be dilutive for stockholders and any debt-based funding may bind us to restrictive covenants and curb our operating activities and ability to pay potential future dividends even when profitable. We cannot guarantee that future financing will be available in sufficient amounts or on acceptable terms, if at all. If we are unable to raise additional capital in sufficient amounts or on acceptable terms, we will be prevented from pursuing research and development efforts. This could harm our business, operating results and financial condition and cause the price of our common stock to fall.

If we are unable to secure sufficient capital to fund our operations, we may be required to delay, limit, reduce or terminate our product development or future commercialization efforts or grant rights to third parties to develop and market products or product candidates that we would otherwise prefer to develop and market ourselves. For example, additional strategic collaborations could require us to share commercial rights to our product candidates with third parties in ways that we do not intend currently or on terms that may not be favorable to us. Moreover, we may also have to relinquish valuable rights to our technologies, future revenue streams, research programs or product candidates or grant licenses on terms that may not be favorable to us.

We are exposed to significant risks related to our ongoing research and development efforts and might not be in a position to successfully develop any product candidate. Any failure to implement our business strategy could negatively impact our business, financial condition and results of operations.

The development and commercialization of IMP321, IMP701, IMP731 and IMP761, or any other product candidate we may develop, is subject to many risks, including:

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If any of these risks materializes, we could experience significant delays or an inability to successfully commercialize IMP321, IMP701, IMP731 and IMP761, or any other product candidate we may develop, which would have a material adverse effect on our business, financial condition and results of operations.

We may not make acquisitions in the future, or if we do, we may not be successful in integrating the acquired company, either of which could have a materially adverse effect on our business.

We completed our acquisition of Immutep, in December 2014 for consideration of up to US$28m in cash and stock. We have almost fully completed the integration of Immutep’s business into our own. We have not yet achieved, and may never achieve, the full benefit of the clinical development expectations, product portfolio enhancements or revenue generations we expected at the time of the acquisition. In addition, even if we achieve the expected benefits, we may be unable to achieve them within the anticipated time frame. Also, there may be unexpected problems in the business unrelated to the Immutep acquisition that have a negative effect on our business. If we fail to implement our business strategy, we may be unable to achieve expected results and our business, financial condition and results of operations may be materially and adversely affected.

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Specific risks associated with the remaining integration include the following:

Immutep is our only significant acquisition in our recent history. Identifying strategic acquisitions is part of our business plan and may become an increasingly important part of our growth. There is, however, no assurance that we will be successful in identifying, negotiating, or consummating any future acquisitions. If we fail to make any future acquisitions, our growth rate could be materially and adversely affected. Any additional acquisitions we undertake could involve the dilutive issuance of equity securities, incurring indebtedness and/or incurring large one-time expenses. In addition, acquisitions involve numerous risks, including difficulties in assimilating the acquired company’s operations, the diversion of our management’s attention from other business concerns, risks of entering into markets in which we have had no or only limited direct experience, and the potential loss of customers, key employees and drivers of the acquired company, all of which could have a materially adverse effect on our business and operating results. If we make acquisitions in the future, we cannot guarantee that we will be able to successfully integrate the acquired companies or assets into our business, which would have a materially adverse effect on our business, financial condition, and results of operations.

Ongoing and future clinical trials of product candidates may not show sufficient safety or efficacy to obtain requisite regulatory approvals for commercial sale.

Phase I and Phase II clinical trials are not primarily designed to test the efficacy of a product candidate but rather to test safety and to understand the product candidate’s side effects at various doses and schedules. Furthermore, success in preclinical and early clinical trials does not ensure that later large-scale trials will be successful nor does it predict final results. Acceptable results in early trials may not be repeated in later trials. Further, Phase III clinical trials may not show sufficient safety or efficacy to obtain regulatory approval for marketing. In addition, clinical results are frequently susceptible to varying interpretations that may delay, limit or prevent regulatory approvals. Negative or inconclusive results or adverse medical events during a clinical trial could require that the clinical trial be redone or terminated. The length of time necessary to complete clinical trials and to submit an application for marketing approval by applicable regulatory authorities may also vary significantly based on the type, complexity and novelty of the product candidate involved, as well as other factors. If we suffer any significant delays, setbacks or negative results in, or termination of, our clinical trials, it may be unable to continue the development of our products or product candidates or generate revenue and our business may be severely harmed.

If we do not obtain the necessary regulatory approvals we will be unable to commercialize our products.

The clinical development, manufacturing, sales and marketing of our products are subject to extensive regulation by regulatory authorities in the United States, the United Kingdom, the European Union, Australia and

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elsewhere. Despite the substantial time and expense invested in preparation and submission of a Biologic License Application or equivalents in other jurisdictions, regulatory approval is never guaranteed. The number, size and design of preclinical studies and clinical trials that will be required will vary depending on the product, the disease or condition for which the product is intended to be used and the regulations and guidance documents applicable to any particular product. The FDA or other regulators can delay, limit or deny approval of a product for many reasons, including, but not limited to, the fact that regulators may not approve our or a third-party manufacturer’s processes or facilities or that new laws may be enacted or regulators may change their approval policies or adopt new regulations requiring new or different evidence of safety and efficacy for the intended use of a product.

IMP321 is undergoing clinical trials; however, successful results in the trials and in the subsequent application for marketing approval are not guaranteed. Without additional clinical trials any other product in the current portfolio cannot obtain a regulatory approval. If we are unable to obtain regulatory approvals, we will not be able to generate revenue from this product. Even if we receive regulatory approval for any product candidate, our profitability will depend on our ability to generate revenues from the sale of those product candidates or the licensing of our technology.

Even if our product candidates receive regulatory approval, they may still face development and regulatory difficulties that may delay or impair their future sales.

Even if we or our licensing partners receive regulatory approval to sell IMP321 or any other product candidate, the relevant regulatory authorities may, nevertheless, impose significant restrictions on the indicated uses, manufacturing, labelling, packaging, adverse event reporting, storage, advertising, promotion and record keeping or impose ongoing requirements for post-approval studies. In addition, regulatory agencies subject a marketed product, its manufacturer and the manufacturer’s facilities to continual review and periodic inspections. Previously unknown problems with the product candidate, including adverse events of unanticipated severity or frequency, may result in restrictions on the marketing of the product, and could include withdrawal of the product from the market. In addition, new statutory requirements may be enacted or additional regulations may be enacted that could prevent or delay regulatory approval of our products.

We have limited manufacturing experience with our product candidates.

We have no manufacturing capabilities and are dependent on third parties for cost effective manufacture and manufacturing process development of the company’s product candidates. Problems with third party manufacturers or the manufacturing process, or the scaling up of manufacturing activities as such may delay clinical trials and commercialization of our product candidates. To minimize the chance of these kinds of disruption, we enter into advance purchase agreements for reagents wherever possible.

Biological product candidates like IMP731, IMP701, IMP321 or IMP761 usually have more complicated manufacturing procedures than chemically produced therapies. The change of manufacturing partners, manufacturing process changes or changes of other nature could impact the product quality and affect the comparability of different product batches. A lack of comparability could significantly impact the development timelines and could even lead to a situation where regulatory bodies require additional or new pre-clinical or clinical development.

The clinical development of autologous dendritic cell cancer vaccines such as CVac is complex and more expensive to produce than most other biologicals such as IMP321. Biologicals like IMP321 offer greater commercial potential based on cost of goods alone. Such lower cost and greater commercial potential were main contributing factors in our decision to focus our clinical trial resources internally on developing IMP321 whilst seeking a partner to develop CVac. With consolidation of the CVac program and the spin off transaction with Sydys Corporation, a US based special purpose vehicle, the manufacturing uncertainties surrounding CVac have now transferred to Sydys. Compared to our other partners Novartis and GlaxoSmithKline who are well funded

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and established within the industry, the transaction with Sydys bears significantly more risk given that Sydys first needs to establish itself and secure significant funds to develop CVac, and there is no guarantee that Sydys will be successful in that respect. The successful approval of CVac by regulatory authorities and the manufacturing of CVac will be beyond the control of Prima.

To the extent we rely significantly on contractors, we will be exposed to risks related to the business and operational conditions of our contractors.

We are a small company, with few internal staff and limited facilities. We are and will be required to rely on a variety of contractors to manufacture and transport our products, to perform clinical testing and to prepare regulatory dossiers. Adverse events that affect one or more of our contractors could adversely affect us, such as:

We depend on, and will continue to depend on, collaboration and strategic alliances with third partners. To the extent we are able to enter into collaborative arrangements or strategic alliances, we will be exposed to risks related to those collaborations and alliances.

An important element of our strategy for developing, manufacturing and commercializing our product candidates is entering into partnerships and strategic alliances with other pharmaceutical companies or other industry participants. For example, we currently have collaborative arrangements with Eddingpharm for the development of IMP321 for China and Taiwan. Any revenues from sales of CVac will be dependent on the success of the collaboration partner. In principle the same applies to IMP731 and IMP701 or any other partnered product candidate.

Any partnerships or alliance we have or may have in the future may be terminated for reasons beyond our control or we may not be able to negotiate future alliances on acceptable terms, if at all. These arrangements may result in us receiving less revenue than if it sold its products directly, may place the development, sales and marketing of its products outside of its control, may require it to relinquish important rights or may otherwise be on unfavorable terms. Collaborative arrangements or strategic alliances will also subject us to a number of risks, including the risk that:

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Our research and development efforts will be jeopardized if we are unable to retain key personnel and cultivate key academic and scientific collaborations.

Our success depends largely on the continued services of our senior management and key scientific personnel and on the efforts and abilities of our senior management to execute our business plan. During the fiscal year ended June 30, 2016, we experienced a significant change in our senior management team with Dr. Sharron Gargosky, our former Chief Technical Officer and past CVac program manager, ceasing to be employed by us effective 30 November 2015. However, we consider the impact of her departure to be minimal with the divestment of CVac to Sydys Corporation. Our research and development activities of IMP321 will be overseen by Dr. Frédéric Triebel, the inventor of the technology.

Changes in our senior management may be disruptive to our business and may adversely affect our operations. For example, when we have changes in senior management positions, we may elect to adopt different business strategies or plans. Any new strategies or plans, if adopted, may not be successful and if any new strategies or plans do not produce the desired results, our business may suffer.

Moreover, competition among biotechnology and pharmaceutical companies for qualified employees is intense and as such we may not be able to attract and retain personnel critical to our success. Our success depends on our continued ability to attract, retain and motivate highly qualified management, clinical and scientific personnel, manufacturing personnel, sales and marketing personnel and on our ability to develop and maintain important relationships with clinicians, scientists and leading academic and health institutions. If we fail to identify, attract, retain and motivate these highly skilled personnel, we may be unable to continue our product development and commercialization activities.

In addition, biotechnology and pharmaceutical industries are subject to rapid and significant technological change. Our product candidates may be or become uncompetitive. To remain competitive, we must employ and retain suitably qualified staff that are continuously educated to keep pace with changing technology, but may not be in a position to do so.

Future potential sales of our products may suffer if they are not accepted in the marketplace by physicians, patients and the medical community.

There is a risk that IMP321 may not gain market acceptance among physicians, patients and the medical community, even if they are approved by the regulatory authorities. The degree of market acceptance of any of our approved products will depend on a variety of factors, including:

Physicians, patients, payers or the medical community may be unwilling to accept, use or recommend our products which would adversely affect our potential revenues and future profitability.

If healthcare insurers and other organizations do not pay for our products or impose limits on reimbursement, our future business may suffer.

Our product candidate may be rejected by the market due to many factors, including cost. The continuing efforts of governments, insurance companies and other payers of healthcare costs to contain or reduce healthcare

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costs may affect our future revenues and profitability. In Australia and certain foreign markets the pricing of pharmaceutical products is already subject to government control. We expect initiatives for similar government control to continue in the United States and elsewhere. The adoption of any such legislative or regulatory proposals could harm our business and prospects.

Successful commercialization of our product candidate will depend in part on the extent to which reimbursement for the cost of our products and related treatment will be available from government health administration authorities, private health insurers and other organizations. Our product candidate may not be considered cost-effective and reimbursement may not be available to consumers or may not be sufficient to allow our products to be marketed on a competitive basis. Third-party payers are increasingly challenging the price of medical products and treatment. If third party coverage is not available for our products the market acceptance of these products will be reduced. Cost-control initiatives could decrease the price we might establish for products, which could result in product revenues lower than anticipated. If the price for our product candidate decreases or if governmental and other third-party payers do not provide adequate coverage and reimbursement levels our potential revenue and prospects for profitability will suffer.

We may be exposed to product liability claims which could harm our business.

The testing, marketing and sale of therapeutic products entails an inherent risk of product liability. We may face product liability exposure related to the testing of our product candidates in human clinical trials. If any of our products are approved for sale, we may face exposure to claims by an even greater number of persons than were involved in the clinical trials once marketing, distribution and sales of our products begin. Regardless of merit or eventual outcome, liability claims may result in:

We rely on a number of third party researchers and contractors to produce, collect, and analyze data regarding the safety and efficacy of our product candidates. We have quality control and quality assurance in place to mitigate these risks, as well as professional liability and clinical trial insurance to cover financial damages in the event that human testing is done incorrectly or the data is analyzed incorrectly. If a claim is made against us in conjunction with these research testing activities, the market price of our ordinary shares or ADSs may be negatively affected. We could also face additional liability beyond insurance limits if testing mistakes were to endanger any human subjects.

We are currently taking advantage of certain exemptions from having to comply with the Sarbanes-Oxley Act due to our status as an “emerging growth company.”

We are an “emerging growth company,” as defined in the Jumpstart Our Business Startups Act of 2012, or the JOBS Act. Accordingly, this allows us to postpone the date by which we must comply with some of the laws and regulations that are otherwise applicable to public companies and to reduce the amount of information we provide in our reports filed with the SEC, which could undermine investor confidence in our company and adversely affect the market price of our ordinary shares or ADSs.

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For so long as we remain an “emerging growth company,” we may take advantage of certain exemptions from various requirements that are applicable to public companies that are not “emerging growth companies,” including, but not limited to, the provisions of Section 404(b) of the Sarbanes-Oxley Act requiring that our independent registered public accounting firm provide an attestation report on the effectiveness of our internal control over financial reporting. As a result, our independent registered public accounting firm will not be required to provide an attestation report on the effectiveness of our internal control over financial reporting for so long as we qualify as an “emerging growth company,” which may increase the risk that weaknesses or deficiencies in our internal control over financial reporting go undetected. Similarly, so long as we qualify as an “emerging growth company,” we may elect not to provide investors with certain information, including certain financial information and certain information regarding compensation of our executive officers, that we would otherwise have been required to provide in filings we make with the SEC, which may make it more difficult for investors and securities analysts to evaluate our company.

We may take advantage of these exemptions until we are no longer an “emerging growth company.” We would cease to be an “emerging growth company” upon the earliest of: (i) the last day of our fiscal year following the fifth anniversary of this offering; (ii) the last day of the first fiscal year in which our annual gross revenues are $1.07 billion or more; (iii) the date on which we have, during a three-year period, issued more than $1 billion in non-convertible debt securities; and (iv) as of the end of any fiscal year in which the market value of our ordinary shares (including ordinary shares represented by ADSs) held by non-affiliates exceeded $700 million as of the end of the second quarter of our last completed fiscal year.

We cannot predict if investors will find our ordinary shares or ADSs less attractive because we may rely on these exemptions. If some investors find our ordinary shares or ADSs less attractive as a result, there may be a less active trading market for such shares, and our stock price may be more volatile and may decline.

Risks Relating to Our Intellectual Property

Our success depends on our ability to protect our intellectual property and our proprietary technology.

Our success is to a certain degree also dependent on our ability to obtain and maintain patent protection or where applicable, to receive/maintain orphan drug designation/status and resulting marketing exclusivity for our product candidates.

We may be materially adversely affected by our failure or inability to protect our intellectual property rights. Without the granting of these rights, the ability to pursue damages for infringement would be limited. Similarly, any know-how that is proprietary or particular to our technologies may be subject to risk of disclosure by employees or consultants despite having confidentiality agreements in place.

Any future success will depend in part on whether we can obtain and maintain patents to protect our own products and technologies; obtain licenses to the patented technologies of third parties; and operate without infringing on the proprietary rights of third parties. Biotechnology patent matters can involve complex legal and scientific questions, and it is impossible to predict the outcome of biotechnology and pharmaceutical patent claims. Any of our future patent applications may not be approved, or we may not develop additional products or processes that are patentable. Some countries in which we may sell our product candidate or license our intellectual property may fail to protect our intellectual property rights to the same extent as the protection that may be afforded in the United States or Australia. Some legal principles remain unresolved and there has not been a consistent policy regarding the breadth or interpretation of claims allowed in patents in the United States, the United Kingdom, the European Union, Australia or elsewhere. In addition, the specific content of patents and patent applications that are necessary to support and interpret patent claims is highly uncertain due to the complex nature of the relevant legal, scientific and factual issues. Changes in either patent laws or in interpretations of patent laws in the United States, the United Kingdom, the European Union or elsewhere may diminish the value of our intellectual property or narrow the scope of our patent protection. Even if we are able to

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obtain patents, they may not issue in a form that will provide us with any meaningful protection, prevent competitors from competing with us or otherwise provide us with any competitive advantage. Our competitors may be able to circumvent our patents by developing similar or alternative technologies or products in a non-infringing manner.

Moreover, any of our pending applications may be subject to a third-party preissuance submission of prior art to the U.S. Patent and Trademark Office, or USPTO, the European Patent Office, or EPO, the Australian Patent and Trademark Office and/or any patents issuing thereon may become involved in opposition, derivation, reexamination, inter partes review, post grant review, interference proceedings or other patent office proceedings or litigation, in the United States or elsewhere, challenging our patent rights. An adverse determination in any such submission, proceeding or litigation could reduce the scope of, or invalidate, our patent rights, and allow third parties to commercialize our technology or products and compete directly with us, without payment to us. In addition, if the breadth or strength of protection provided by our patents and patent applications is threatened, it could dissuade companies from collaborating with us to exploit our intellectual property or develop or commercialize current or future product candidate.

The issuance of a patent is not conclusive as to the inventorship, scope, validity or enforceability, and our patents may be challenged in the courts or patent offices in the U.S., the EU, Australia and elsewhere. Such challenges may result in loss of ownership or in patent claims being narrowed, invalidated or held unenforceable, in whole or in part, which could limit the duration of the patent protection of our technology and products. As a result, our patent portfolio may not provide us with sufficient rights to exclude others from commercializing products similar or identical to ours.

In addition, other companies may attempt to circumvent any regulatory data protection or market exclusivity that we obtain under applicable legislation, which may require us to allocate significant resources to preventing such circumvention. Such developments could enable other companies to circumvent our intellectual property rights and use our clinical trial data to obtain marketing authorizations in the EU, Australia and in other jurisdictions. Such developments may also require us to allocate significant resources to prevent other companies from circumventing or violating our intellectual property rights.

Our attempts to prevent third parties from circumventing our intellectual property and other rights may ultimately be unsuccessful. We may also fail to take the required actions or pay the necessary fees to maintain our patents.

Intellectual property rights of third parties could adversely affect our ability to commercialize our products, such that we could be required to litigate with or obtain licenses from third parties in order to develop or market our products. Such litigation or licenses could be costly or not available on commercially reasonable terms.

Our commercial success may somewhat depend upon our future ability and the ability of our potential collaborators to develop, manufacture, market and sell our product candidates without infringing valid intellectual property rights of third parties.

If a third-party intellectual property right exists that requires the pursuit of litigation or administrative proceedings to nullify or invalidate the third-party intellectual property right concerned, or enter into a license agreement with the intellectual property right holder, which may not be available on commercially reasonable terms, if at all.

Third-party intellectual property right holders, including our competitors, may bring infringement claims against us. We may not be able to successfully settle or otherwise resolve such infringement claims. If we are unable to successfully settle future claims or otherwise resolve such claims on terms acceptable to us, we may be

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required to engage in or continue costly, unpredictable and time-consuming litigation and may be prevented from, or experience substantial delays in, marketing our product candidate.

If we fail to settle or otherwise resolve any such dispute, in addition to being forced to pay damages, we or our potential collaborators may be prohibited from commercializing any product candidates we may develop that are held to be infringing, for the duration of the patent term. We might, if possible, also be forced to redesign our formulations so that we no longer infringe such third-party intellectual property rights. Any of these events, even if we were ultimately to prevail, could require us to divert substantial financial and management resources that we would otherwise be able to devote to our business.

To mitigate this risk, we have a patent strategy and monopoly around many of the technical areas we operate in with little room for others to achieve freedom to operate. From time to time we engage the advice of patent counsel to conduct checks on the freedom to operate position of our business with respect to claims protecting our product development candidates and our clinical and manufacturing strategies.

We may become involved in lawsuits to protect and defend our patents or other intellectual property, which could be expensive, time consuming and unsuccessful.

Competitors may infringe our patents or other intellectual property and we may inadvertently infringe the patent or intellectual property of others. To counter infringement or unauthorized use, we may be required to file claims, and any related litigation and/or prosecution of such claims can be expensive and time consuming. Any claims we assert against perceived infringers could provoke these parties to assert counterclaims against us alleging that we infringe their intellectual property. In addition, in a patent infringement proceeding, a court may decide that a patent of ours is invalid in whole or in part, unenforceable, or construe the patent’s claims narrowly allowing the other party to commercialize competing products on the grounds that our patents do not cover such products.

Even if resolved in our favor, litigation or other legal proceedings relating to intellectual property claims may cause us to incur significant expenses and could distract our technical and management personnel from their normal responsibilities. Such litigation or proceedings could substantially increase our operating losses and reduce our resources available for development activities. We may not have sufficient financial or other resources to adequately conduct such litigation or proceedings. Some of our competitors may be able to sustain the costs of such litigation or proceedings more effectively than we can because of their substantially greater financial resources. The effects of patent litigation or other proceedings could therefore have a material adverse effect on our ability to compete in the marketplace.

Confidentiality and invention assignment agreements with our employees, advisors and consultants may not adequately prevent disclosure of trade secrets and protect other proprietary information.

We consider proprietary trade secrets and/or confidential know-how and unpatented know-how to be important to our business. We may rely on trade secrets and/or confidential know-how to protect our technology, especially where patent protection is believed by us to be of limited value. However, trade secrets and/or confidential know-how can be difficult to maintain as confidential.

To protect this type of information against disclosure or appropriation by competitors, our policy is to require our employees, advisors and consultants to enter into confidentiality and invention assignment agreements with us. However, current or former employees, advisors and consultants may unintentionally or willfully disclose our confidential information to competitors, and confidentiality and invention assignment agreements may not provide an adequate remedy in the event of unauthorized disclosure of confidential information. Enforcing a claim that a third-party obtained illegally and is using trade secrets and/or confidential know-how is expensive, time consuming and unpredictable. The enforceability of confidentiality and invention assignment agreements may vary from jurisdiction to jurisdiction.

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Failure to obtain or maintain trade secrets and/or confidential know-how trade protection could adversely affect our competitive position. Moreover, our competitors may independently develop substantially equivalent proprietary information and may even apply for patent protection in respect of the same. If successful in obtaining such patent protection, our competitors could limit our use of our trade secrets and/or confidential know-how.

Intellectual property rights do not address all potential threats to our competitive advantage.

The degree of future protection afforded by our intellectual property rights is uncertain because intellectual property rights have limitations, and may not adequately protect our business, or permit us to maintain our competitive advantage. The following examples are illustrative:

Changes in patent laws or patent jurisprudence could diminish the value of patents in general, thereby impairing our ability to protect our products or product candidate.

As is the case with other biopharmaceutical companies, our success is heavily dependent on intellectual property, particularly patents. Obtaining and exploiting patents in the biopharmaceutical industry involve both technological and legal complexity. Therefore, obtaining and exploiting biopharmaceutical patents is costly, time-consuming and inherently uncertain. The U.S. Supreme Court has ruled on several patent cases in recent years, either narrowing the scope of patent protection available in certain circumstances or weakening the rights of patent owners in certain situations. Such examples include:

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In addition, the America Invents Act, or AIA, has been recently enacted in the United States, resulting in significant changes to the U.S. patent system. In addition to increasing uncertainty with regard to our ability to obtain patents in the future, the combination of the U.S. Supreme Court decisions and AIA has created uncertainty with respect to the value of patents, once obtained. A few highlights of changes to U.S. patent law under the AIA are:

The “first-inventor-to-file” system and the new definitions of prior art apply to U.S. patent applications with claims having an effective filing date on or after March 16, 2013. Until at least 2034, patent practice will involve both pre-AIA and AIA laws.

Depending on decisions by the U.S. Congress, the federal courts, and the USPTO, the laws and regulations governing patents could change in unpredictable ways that could weaken our ability to obtain new patents or to exploit our existing patents and patents that we might obtain in the future. Similarly, the complexity and uncertainty of European patent laws has also increased in recent years. In addition, the European patent system is relatively stringent in the type of amendments that are allowed during prosecution. Changes in patent law or patent jurisprudence could limit our ability to obtain new patents in the future that may be important for our business.

We may face difficulties with protecting our intellectual property in certain jurisdictions, which may diminish the value of our intellectual property rights in those jurisdictions.

The laws of some jurisdictions do not protect intellectual property rights to the same extent as the laws in the U.S. and the EU, and many companies have encountered significant difficulties in protecting and defending such rights in such jurisdictions. If we or our collaboration partners encounter difficulties in protecting, or are otherwise precluded from effectively protecting, the intellectual property rights important for our business in such jurisdictions, the value of these rights may be diminished and we may face additional competition from others in those jurisdictions.

Some countries in Europe and China have compulsory licensing laws under which a patent owner may be compelled to grant licenses to third parties. In addition, many countries limit the enforceability of patents against

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government agencies or government contractors. In these countries, the patent owner may have limited remedies, which could materially diminish the value of such patent. If we or any of our licensors is forced to grant a license to third parties with respect to any patents relevant to our business, our competitive position or commercial advantage may be impaired and our business and results of operations may be adversely affected.

Risks Relating to Our Location in Australia

Currency fluctuations may expose us to increased costs and revenue decreases.

Our business is affected by fluctuations in foreign exchange rates. Currency fluctuations could, therefore, cause our costs to increase and revenues to decline. Our expenses will be denominated in Australian dollars, U.S. dollars and European euro. Last year, the Australian dollar has, as a general trend, depreciated against the U.S. dollar and European euro, whereas two years ago, the Australian dollar had appreciated against the U.S. dollar and European Euro. We conduct clinical trials in many different countries and we have manufacturing of our product candidate undertaken outside of Australia, which exposes us to potential cost increases resulting from fluctuations in exchange rates. In fiscal 2015, we made foreign exchange gains as a result of currency fluctuations of A$0.5 million. In fiscal 2014 our foreign exchange gain was A$0.4 million. In fiscal 2016, we made foreign exchange losses as a result of currency fluctuations of A$0.6 million. For the nine-month period ended March 31, 2017, the loss on foreign exchange was A$0.6 million, an increase of approximately A$0.1 million over the prior-year period, driven by the foreign exchange impact on the U.S. and euro holdings compared to the prior-year period.

Australian takeovers laws may discourage takeover offers being made for us or may discourage the acquisition of large numbers of our shares.

We are incorporated in Australia and are subject to the takeovers laws of Australia. Amongst other things, we are subject to the Corporations Act 2001 (Commonwealth of Australia). Subject to a range of exceptions, the Corporations Act prohibits the acquisition of a direct or indirect interest in our issued voting shares (including through the acquisition of ADSs) if the acquisition of that interest will lead to a person’s or someone else’s voting power in us increasing from 20% or below to more than 20%, or increasing from a starting point that is above 20% and below 90%. Exceptions to the general prohibition include circumstances where the person makes a formal takeover bid for us, if the person obtains shareholder approval for the acquisition or if the person acquires less than 3% of the voting power of us in any rolling six month period. Australian takeovers laws may discourage takeover offers being made for us or may discourage the acquisition of large numbers of our shares. See “Australian Change in Control and Disclosure of Interest Requirements.”

Rights as a holder of ordinary shares are governed by Australian law and our Constitution and differ from the rights of shareholders under U.S. law. Holders of our ordinary shares or ADSs may have difficulty in effecting service of process in the United States or enforcing judgments obtained in the United States.

We are a public company incorporated under the laws of Australia. Therefore, the rights of holders of our ordinary shares are governed by Australian law and our Constitution. These rights differ from the typical rights of shareholders in U.S. corporations. The rights of holders of ADSs are affected by Australian law and our Constitution but are governed by U.S. law. Circumstances that under U.S. law may entitle a shareholder in a U.S. company to claim damages may also give rise to a cause of action under Australian law entitling a shareholder in an Australian company to claim damages. However, this will not always be the case. Holders of our ordinary shares or ADSs may have difficulties enforcing, in actions brought in courts in jurisdictions located outside the U.S., liabilities under U.S. securities laws. In particular, if such a holder sought to bring proceedings in Australia based on U.S. securities laws, the Australian court might consider:

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Holders of our ordinary shares and ADSs may also have difficulties enforcing in courts outside the U.S. judgments obtained in the U.S. courts against any of our directors and executive officers or us, including actions under the civil liability provisions of the U.S. securities laws.

As a foreign private issuer whose shares are listed on the NASDAQ Global Market, we may follow certain home country corporate governance practices instead of certain NASDAQ requirements.

As a foreign private issuer whose shares are listed on the NASDAQ Global Market, we are permitted to follow certain home country corporate governance practices instead of certain requirements of The NASDAQ Marketplace Rules. As an Australian company listed on the NASDAQ Global Market, we may follow home country practice with regard to, among other things, the composition of the board of directors, director nomination process, compensation of officers and quorum at shareholders’ meetings. In addition, we may follow Australian law instead of the NASDAQ Marketplace Rules that require that we obtain shareholder approval for certain dilutive events, such as for the establishment or amendment of certain equity based compensation plans, an issuance that will result in a change of control of the company, certain transactions other than a public offering involving issuances of a 20% or more interest in the company and certain acquisitions of the stock or assets of another company. As a foreign private issuer that has elected to follow a home country practice instead of NASDAQ requirements, we have submitted to NASDAQ a written statement from our independent counsel certifying that our practices are not prohibited by Australian laws. In addition, a foreign private issuer must disclose in Annual Reports filed with the U.S. Securities and Exchange Commission each such requirement that it does not follow and describe the home country practice followed by the issuer instead of any such requirement. Accordingly, our shareholders may not be afforded the same protection as provided under NASDAQ’s corporate governance rules.

We are exposed to differing legal and tax laws in multiple jurisdictions, including complex transfer pricing rules in Australia.

We and our subsidiaries are located in a number of jurisdictions and therefore have exposure to different legal and taxation requirements in multiple jurisdictions. The listed entity Prima Biomed Ltd is incorporated in, and a tax resident of, Australia. It has a number of intercompany arrangements with its subsidiaries (resident outside Australia), including, for example, funding and employee sourcing arrangements. In Australia there are complex and material requirements on transfer pricing of intercompany loan arrangements with overseas entities. The multiple jurisdictional structure of the Company and its subsidiaries can expose the group to substantial compliance and taxation liabilities. While we believe we are compliant with these tax laws, there is a risk that we and our subsidiaries could be subject to tax audits (with the resulting compliance costs) or exposed to fines or penalties.

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RISK FACTORS

Investing in the ADSs involves a high degree of risk. You should carefully review the risks and uncertainties described in our Annual Report on Form 20-F filed with the SEC, and all other information contained in or incorporated by reference in this prospectus (as supplemented and amended), before deciding whether to purchase any of our ADSs. Each of the risk factors could adversely affect our business, operating results and financial condition, as well as adversely affect the value of an investment in our ADSs, and the occurrence of any of these risks might cause you to lose all or part of your investment. Moreover, the risks described are not the only ones that we face. Additional risks not presently known to us or that we currently believe are immaterial may also significantly impair our business operations.