EXPLANATORY NOTE
On October 13, 2022, Enliven Therapeutics, Inc. (formerly known as Imara Inc.) (the Registrant) entered into an Agreement and Plan of
Merger (the Merger Agreement) with Enliven Inc. (formerly Enliven Therapeutics, Inc.) (Former Enliven) and Iguana Merger Sub, Inc., a wholly-owned subsidiary of the Registrant (Merger
Sub), pursuant to which, among other matters, subject to the terms and conditions thereof, Merger Sub merged with and into Former Enliven, with Former Enliven surviving such merger as a wholly-owned subsidiary of the Registrant and the
surviving corporation of the merger (the Merger). On February 23, 2023, the Registrant completed the Merger. Upon the closing of the Merger, Imara Inc. was renamed Enliven Therapeutics, Inc.
On February 22, 2023, at a special meeting of stockholders, the stockholders of the Registrant approved an amendment to the Registrants restated
certificate of incorporation to effect a reverse stock split (as defined below) of the Registrants common stock, par value $0.001 per share (the Common Stock), the Registrants Amended and Restated 2020 Equity Incentive
Plan (the 2020 Plan), and an amendment to the Registrants 2020 Employee Stock Purchase Plan (the 2020 ESPP) to increase the number of shares reserved for issuance under the 2020 ESPP to 1,628,535 shares of
Common Stock (subject to certain capitalization adjustments, and not accounting for the Reverse Stock Split). On February 23, 2023, the Registrant effected a 1-for-4 reverse stock split of its Common
Stock (the Reverse Stock Split) and implemented a reduction in the number of authorized shares of Common Stock to 100,000,000.
In
connection with the Merger, each stock option granted under Former Enlivens 2019 Equity Incentive Plan (the Former Enliven 2019 Plan) that was outstanding immediately prior to the effective time of the Merger
was assumed by the Registrant and became an option to acquire, on the same terms and conditions as were applicable to such Former Enliven stock option immediately prior to the effective time of the Merger, a number of shares of Common Stock equal to
the number of shares of Former Enliven common stock subject to the unexercised portion of the Former Enliven stock option immediately prior to the effective time of the Merger, multiplied by the exchange ratio (rounded down to the nearest whole
share number), with an exercise price per share for the options equal to the exercise price per share of such Former Enliven stock option immediately prior to the effective time of the Merger divided by the exchange ratio (rounded up to the nearest
whole cent). Such assumed options continue to be governed by the terms and conditions of the Former Enliven 2019 Plan. Upon the closing of the Merger, the Registrant assumed the Former Enliven 2019 Plan.
The number of shares of Common Stock reserved and available for issuance under the 2020 Plan is subject to an automatic annual increase on the first day of
each fiscal year during the term of the plan, beginning with the fiscal year commencing on January 1, 2024, equal to the least of (i) 4.5% of the number of shares of the Registrants Common Stock outstanding on the first day of such fiscal
year or (ii) an amount determined by the Registrants board of directors; provided that, subject to certain capitalization adjustments, up to 17,100,000 shares of Common Stock may be granted as incentive stock options
under the 2020 Plan (not accounting for the Reverse Stock Split).
The number of shares of Common Stock reserved and available for issuance under the 2020
ESPP is subject to an automatic increase on the first day of each fiscal year, beginning with the fiscal year commencing on January 1, 2024 and continuing until, and including, the fiscal year commencing on January 1, 2043, in an amount
equal to the least of (i) 1,628,535 shares of Common Stock (subject to certain capitalization adjustments, and not accounting for the Reverse Stock Split), (ii) 1% of the number of shares of Common Stock outstanding on the first day of such fiscal
year and (iii) an amount determined by the Registrants board of directors.
The Registrant is filing this Registration Statement on Form S-8 (the Registration Statement) with the Securities and Exchange Commission (the Commission) to register (i) 3,155,125 shares of Common Stock, issuable with respect to Former
Enliven options assumed by the Registrant pursuant to the Merger Agreement, (ii) 3,531,575 additional shares of Common Stock under the 2020 Plan, pursuant to the stockholder vote providing for such increase in the number of shares reserved for
issuance, and (iii) 293,111 additional shares of Common Stock under the 2020 ESPP, pursuant to the stockholder vote providing for such increase in the number of shares reserved for issuance. All applicable share amounts reflect the Reverse Stock
Split.