X0206 3 2023-10-31 0 0001420565 AILERON THERAPEUTICS INC ALRN 0001790933 WINDSOR JAMES BRIAN C/O AILERON THERAPEUTICS, INC. 738 MAIN STREET #398 WALTHAM MA 02451 0 1 0 0 See Remarks Common Stock 46 D Stock Option (right to buy) 0.29 2025-09-29 Common Stock 8532 D Stock Option (right to buy) 0.70 2027-10-09 Common Stock 252652 D Stock Option (right to buy) 0.70 2028-03-14 Common Stock 34736 D Stock Option (right to buy) 1.17 2030-02-25 Common Stock 317613 D Stock Option (right to buy) 1.17 2030-02-25 Common Stock 139900 D Stock Option (right to buy) 3.87 2033-10-19 Common Stock 170646 D Series X Non-Voting Convertible Preferred Stock Common Stock 2709 D On October 31, 2023, the Issuer completed its merger with Lung Therapeutics, Inc. (the "Merger") in accordance with the terms of the Agreement and Plan of Merger, dated October 31, 2023. In connection with the Merger, the Reporting Person received 46 shares of Issuer common stock and 2,709 shares of Issuer series X non-voting convertible preferred stock in exchange for an aggregate of 16,152 shares of Lung Therapeutics, Inc. preferred stock. In connection with the Merger, the Issuer assumed the Reporting Person's option to purchase 50,000 shares of Lung Therapeutics, Inc. common stock originally granted on September 30, 2015, which option was converted into an option to purchase 8,532 shares of Issuer common stock. The shares underlying the option are fully vested. In connection with the Merger, the Issuer assumed the Reporting Person's option to purchase 1,480,558 shares of Lung Therapeutics, Inc. common stock originally granted on October 10, 2017, which option was converted into an option to purchase 252,652 shares of Issuer common stock. 209,469 shares of Issuer common stock underlying the option have vested. The remaining 43,183 shares of Issuer common stock underlying the option vest upon the date of the first to occur of (i) a change of control in which Lung Therapeutics, Inc. is sold for a valuation per share of greater than $1.8573 per share of common stock or (ii) the completion of an offering of Lung Therapeutics, Inc.'s equity securities at a valuation of greater than $1.2382 per share of common stock, subject to the Reporting Person's continued service with the Issuer on the vesting date. In connection with the Merger, the Issuer assumed the Reporting Person's option to purchase 203,558 shares of Lung Therapeutics, Inc. common stock originally granted on March 15, 2018, which option was converted into an option to purchase 34,736 shares of Issuer common stock. The shares underlying the option are fully vested. In connection with the Merger, the Issuer assumed the Reporting Person's option to purchase 1,861,235 shares of Lung Therapeutics, Inc. common stock originally granted on February 26, 2020, which option was converted into an option to purchase 317,613 shares of Issuer common stock. 25% of the shares underlying the option vested on the first anniversary of the grant date, and, thereafter, the remaining 75% of such shares vest in thirty-six (36) equal monthly installments, subject to the Reporting Person's continued service with the Issuer on each applicable vesting date. In connection with the Merger, the Issuer assumed the Reporting Person's option to purchase 819,823 shares of Lung Therapeutics, Inc. common stock originally granted on February 26, 2020, which option was converted into an option to purchase 139,900 shares of Issuer common stock. 25% of the shares underlying the option vested on the first anniversary of the grant date, and, thereafter, the remaining 75% of such shares vest in thirty-six (36) equal monthly installments, subject to the Reporting Person's continued service with the Issuer on each applicable vesting date. In connection with the Merger, the Issuer assumed the Reporting Person's option to purchase 1,000,000 shares of Lung Therapeutics, Inc. common stock originally granted on October 20, 2023, which option was converted into an option to purchase 170,646 shares of Issuer common stock. The shares underlying the option are fully vested on the grant date. In connection with the Merger, the Reporting Person's options reported in this Form 3 were amended to provide that no shares underlying such options will vest as a result of the Merger and such options will not be exercisable until the Issuer's stockholders approve the conversion of the series X non-voting convertible preferred stock. Upon stockholder approval of the conversion of series X non-voting convertible preferred stock into shares of common stock, each share of series X non-voting convertible preferred stock will convert into 1,000 shares common stock, subject to certain limitations. Exhibit 24.1 Power of Attorney President and Chief Operating Officer /s/ Manuel C. Alves-Aivado, M.D., Ph.D., as attorney-in-fact for James Brian Windsor 2023-11-02