ACIU AC Immune SA

Item 1.

(a) Name of issuer:

AC Immune SA

(b) Address of issuer's principal executive offices:

EPFL Innovation Park, bâtiment B, 1015 Lausanne, Switzerland

Item 2.

(a) Names of persons filing:

Affiris and Certain of Its Shareholders

(i) Affiris AG ("Affiris"), (ii) MIG GmbH & Co. Fonds 15 geschlossene Investment-KG, MIG Asset Trust GmbH, MIG GmbH & Co. Fonds 4 KG, MIG GmbH & Co. Fonds 5 KG i.L., MIG GmbH & Co. Fonds 7 KG i.L., MIG GmbH & Co. Fonds 11 KG i.L., MIG GmbH & Co. Fonds 12 geschlossene Investment-KG, MIG GmbH & Co. Fonds 13 geschlossene Investment-KG (collectively, the "MIG Shareholders"), (iii) Santo Venture Capital GmbH ("Santo"), and (iv) FCPB Affi GmbH ("FCPB").

Additional Filing Persons Related to the MIG Shareholders

In addition to the forgoing persons, MIG Verwaltungs AG controls investment decisions with respect to investments held by the MIG Shareholders. Michael Motschmann is the majority shareholder of this entity.

MIG Komplementär GmbH serves as general partner of MIG GmbH & Co. Fonds 4 KG and MIG GmbH & Co. Fonds 5 KG i.L. MIG Komplementär GmbH is a subsidiary of MIG Verwaltungs AG. HMW Verwaltungs GmbH serves as general partner of MIG GmbH & Co. Fonds 7 KG i.L. and MIG GmbH & Co. Fonds 11 KG i.L., and HMW Komplementär GmbH serves as general partner of MIG GmbH & Co. Fonds 15 geschlossene Investment-KG, MIG GmbH & Co. Fonds 12 geschlossene Investment-KG and MIG GmbH & Co. Fonds 13 geschlossene Investment-KG.  These entities are subsidiaries of HMW Emissionshaus AG.  Dr. Matthias Hallweger is the majority shareholder of this entity.

Additional Filing Persons Related to Santo and FCPB

Santo is wholly owned by Santo Holding (Deutschland) GmbH, which in turn is wholly owned by Athos KG.

FCPB is wholly owned by FCP Biotech Holding GmbH ("FCP Biotech"), which is wholly owned by First Capital Partner GmbH, which is wholly owned by we holding GmbH & Co. KG, which in turn is wholly owned by Wolfgang Egger. FCPB intends to transfer the convertible notes discussed in this filing to FCP Biotech during the third quarter of 2021.

* * *

An agreement among the filing persons that this Schedule 13G is filed on behalf of each of them is attached hereto as Exhibit 1.

(b) Addresses or principal business offices or, if none, residence:

For Affiris, Karl-Farkas-Gasse 22, 1030 Vienna, Austria

For MIG GmbH & Co. Fonds 15 geschlossene Investment-KG, MIG GmbH & Co. Fonds 13 geschlossene Investment-KG  and MIG GmbH & Co. Fonds 12 geschlossene Investment-KG,  Münchner Str. 52, 82049 Pullach, Germany.

For the other MIG Shareholders, Ismaninger Straße 102, 81675 Munich, Germany

For MIG Verwaltungs AG, Ismaninger Straße 102, 81675 Munich, Germany

For Michael Motschmann, Ismaninger Straße 102, 81675 Munich, Germany

For MIG Komplementär GmbH, Ismaninger Straße 102, 81675 Munich, Germany

For HMW Komplementär GmbH, Münchner Str. 52, 82049 Pullach, Germany

For HMW Verwaltungs GmbH, Münchner Str. 52, 82049 Pullach, Germany

For HMW Emissionshaus AG, Münchner Str. 52, 82049 Pullach, Germany

Dr. Matthias Hallweger, Münchner Str. 52, 82049 Pullach, Germany

For Santo, Bergfeldstraße 9, 83607 Holzkirchen, Germany

For Santo Holding (Deutschland) GmbH, Bergfeldstrasse 9, 83607 Holdkirchen, Germany

For Athos KG, Bergfeldstraße 9, 83607 Holzkirchen

For FCPB, Freihamer Straße 2, 82166 Gräfelfing, Germany

For FCP Biotech Holding GmbH, Freihamer Str. 2, 82166 Gräfelfing

For First Capital Partner GmbH, Freihamer Str. 2, 82166 Gräfelfing, Germany

For we holding GmbH & Co. KG, Freihamer Str. 2, 82166 Gräfelfing, Germany

For Wolfgang Egger, Gärtnerstr. 31, 86161 Augsburg, Germany

(c) Citizenship:

For Affiris, Austria.

For the remaining filing persons, Germany.

(d) Title of class of securities:

Ordinary shares.

(e) CUSIP No.: H00263105

Item 3. If this statement is filed pursuant to §§240.13d–1(b) or 240.13d–2(b) or (c), check whether the person filing is a:

Not applicable.

Item 4. Ownership

Provide the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1.

(a) Amount beneficially owned:

On July 26, 2021, the filing persons entered into agreements pursuant to which Affiris agreed to purchase an estimated 7,106,840 of the Issuer's ordinary shares. In addition, Santo and FCPB agreed to purchase notes that are convertible into a maximum of 1,513,317 of the Issuer's ordinary shares for each of those investors.

The MIG Shareholders, Santo and FCPB collectively own the majority of Affiris's equity securities. These filing persons agreed, among other things, to certain limitations on the Affiris's ability to sell or transfer the ordinary shares held by Affiris, including certain potential distributions by Affiris to the MIG Investors, Santo and FCPB. Accordingly, the filing persons may be deemed to be a "group" for purposes of the shares held by Affiris; however , consistent with Item 2 of the cover page for each filing person, the filing persons neither disclaim nor affirm the existence of a group among them.

(b) Percent of class:

See line 11 of the cover sheets. The percentages set forth are based on 83,994,289 shares of the issuer that are expected be outstanding upon the closing of the issuance of shares to Affiris described in the first paragraph of paragraph (a) above.

(c) Number of shares as to which the person has:

(i) Sole power to vote or to direct the vote:

See line 5 of the cover sheets.

(ii) Shared power to vote or to direct the vote:

See line 6 of the cover sheets.

(iii) Sole power to dispose or to direct the disposition of:

See line 7 of the cover sheets.

(iv) Shared power to dispose or to direct the disposition of:

See line 8 of the cover sheets.

Each of the filing persons (other than Affiris) disclaim beneficial ownership of the shares held by Affiris, except to the extent they have a pecuniary interest therein.

Item 5. Ownership of 5 Percent or Less of a Class.

If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than 5 percent of the class of securities, check the following o.

Item 6. Ownership of More than 5 Percent on Behalf of Another Person.

Not Applicable

Item 7. Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.

Not Applicable.

Item 8. Identification and Classification of Members of the Group

The filing persons may be deemed to be members of a group as to the shares beneficially held by Affiris. Each of the filing persons (other than Affiris) disclaim beneficial ownership of the shares held by Affiris, except to the extent they have a pecuniary interest therein.

Item 9. Notice of Dissolution of Group.

Not Applicable

Item 10. Certifications

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect

SIGNATURES

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

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