Convertible Preferred Stock and Stockholders’ Equity | 8. Convertible Preferred Stock and Stockholders’ Equity Convertible Preferred Stock In November 2016, the Company completed a private placement of stock in which investors, including investors affiliated with the directors and officers of the Company, purchased convertible preferred stock and common stock of the Company (the November 2016 Placement). The Company issued 2,819,549 shares of Class A Convertible Preferred Stock, $ 0.001 par value per share (the Class A Preferred), at $ 13.30 per share, each of which is convertible into five shares of common stock upon certain conditions defined in the Certificate of Designation of Preferences, Rights and Limitations of the Class A Preferred filed with the Delaware Secretary of State on November 22, 2016 (the CoD). The Class A Preferred were purchased exclusively by entities affiliated with Redmile Group, LLC (collectively, Redmile). The terms of the CoD prohibited Redmile from converting the Class A Preferred into shares of the Company’s common stock if, as a result of conversion, Redmile, together with its affiliates, would own more than 9.99 % of the Company’s common stock then issued and outstanding (the Redmile Percentage Limitation), which percentage could change at Redmile’s election upon 61 days’ notice to the Company to (i) any other number less than or equal to 19.99 % or (ii) subject to approval of the Company’s stockholders to the extent required in accordance with the NASDAQ Global Market rules, any number in excess of 19.99 %. On May 2, 2017, the Company’s stockholders approved the issuance of up to an aggregate of 14,097,745 shares of common stock upon the conversion of the outstanding shares of Class A Preferred. As a result, Redmile has the right to increase the Redmile Percentage Limitation to any percentage in excess of 19.99 % at its election. The Company also issued 7,236,837 shares of common stock at $ 2.66 per share as part of the November 2016 Placement. In April 2023, the Company filed with the office of the Secretary of State of the State of Delaware a Certificate of Amendment to Certificate of Designation of Preferences, Rights and Limitations of Class A Convertible Preferred Stock which amends the definition of Beneficial Ownership Limitation to be 14.99 % of the number of shares of the Company ’s common stock outstanding immediately after giving effect to the issuance of shares of common stock pursuant to a Notice of Conversion. In April 2023, 33,441 shares of the Company ’ s Class A Preferred were converted into 167,205 shares of the Company ’s common stock. The Class A Preferred are non-voting shares and are convertible into five shares of the Company’s common stock at a conversion price of $ 2.66 per share, which was the fair value of the Company’s common stock on the date of issuance of the Class A Preferred. Holders of the Class A Preferred have the same dividend rights as holders of the Company’s common stock. Additionally, the liquidation preferences of the Class A Preferred are pari passu among holders of the Company’s common stock and holders of the Class A Preferred, pro rata based on the number of shares held by each such holder (treated for this purpose as if the Class A Preferred had been converted to common stock). Pre-Funded Warrants In January 2021, in conjunction with a public offering, the Company issued pre-funded warrants, in lieu of common stock to certain investors, to purchase 257,310 shares of the Company’s common stock (2021 Pre-Funded Warrants). The purchase price for the 2021 Pre-Funded Warrants was $ 85.499 per pre-funded warrant, which equals the per share public offering price for the shares of common stock less the $ 0.001 exercise price for each such pre-funded warrant. Given that the 2021 Pre-Funded Warrants are indexed to the Company’s own shares of common stock (and otherwise meet the requirements to be classified in equity), the Company recorded the consideration received from the issuance of the warrants as additional paid-in capital on the Company’s unaudited condensed consolidated balance sheets. In March 2024, in conjunction with a public offering, the Company issued in a private placement, in lieu of common stock to certain investors, pre-funded warrants to purchase 3,636,364 shares of the Company’s common stock (2024 Pre-Funded Warrants, and collectively with the 2021 Pre-Funded Warrants, the Pre-Funded Warrants). The purchase price for the 2024 Pre-Funded Warrants was $ 5.499 per pre-funded warrant, which equals the per share public offering price for the shares of common stock issued in the March 2024 public offering, less the $ 0.001 exercise price for each such pre-funded warrant. Given that the 2024 Pre-Funded Warrants are indexed to the Company’s own shares of common stock (and otherwise meet the requirements to be classified in equity), the Company recorded the consideration received from the issuance of the warrants as additional paid-in capital on the Company’s unaudited condensed consolidated balance sheets. The Pre-Funded Warrants are exercisable at any time after the date of issuance. A holder of Pre-Funded Warrants may not exercise the Pre-Funded Warrant if the holder, together with its affiliates, would beneficially own more than 9.99 % of the number of shares of the Company’s common stock outstanding immediately after giving effect to such exercise. A holder of Pre-Funded Warrants may increase or decrease this percentage not in excess of 19.99 % by providing at least 61 days’ prior notice to the Company . As of June 30, 2024, there w ere 3,893,674 Pre-Funded Warrants outstanding. Stock Options and Restricted Stock Unit Awards The following table summarizes stock option activity and related information under all equity plans for the period ended June 30, 2024: Number of Weighted- Balance at December 31, 2023 9,850,841 $ 13.71 Granted 4,130,625 6.48 Exercised ( 45,438 ) 6.57 Cancelled ( 1,363,425 ) 7.25 Balance at June 30, 2024 12,572,603 $ 12.06 Restricted stock unit activity under all equity and stock option plans is summarized as follows: Number of Weighted- Balance at December 31, 2023 3,065,087 $ 37.96 Granted 1,097,000 6.72 Vested ( 631,589 ) 31.98 Cancelled ( 270,806 ) 38.98 Balance at June 30, 2024 3,259,692 $ 28.50 The allocation of stock-based compensation for all stock awards is as follows (in thousands): Three Months Ended Six Months Ended 2024 2023 2024 2023 Research and development $ 5,237 $ 6,851 $ 10,953 $ 11,907 General and administrative 4,393 6,046 9,658 11,973 Total $ 9,630 $ 12,897 $ 20,611 $ 23,880 As of June 30, 2024, the unrecognized compensation cost rel ated to outstanding options was $ 27.7 million and is expected to be recognized as expense over a weighted-average period of approximately 1.9 years. As of June 30, 2024 , the unrecognized compensation cost related to restricted stock units was $ 31.0 million which is expected to be recognized as expense over a weighted-average period of approximately 2.0 years. The weighted-average assumptions used in the Black-Scholes option pricing model to determine the fair value of the employee and nonemployee stock option grants were as follows: Six Months Ended 2024 2023 Risk-free interest rate 3.9 % 3.8 % Expected volatility 87.1 % 89.6 % Expected term (in years) 6.4 6.5 Expected dividend yield 0.0 % 0.0 % Reconciliation of Consolidated Stockholders’ Equity Accounts The following table summarizes the Company’s changes in stockholders’ equity accounts for the three and six months ended June 30, 2024 (in thousands, except share data): Convertible Common Additional Accumulated Accumulated Total Stockholders' Shares Amount Shares Amount Capital Gain (Loss) Deficit Equity Balance at December 31, 2023 2,761,108 $ 3 98,627,076 $ 99 $ 1,580,032 $ 15 $ ( 1,211,732 ) $ 368,417 Exercise of stock options, net of issuance costs — — 45,438 — 299 — — 299 Issuance of common stock upon vesting of restricted stock units — — 580,974 — — — — — Stock-based compensation — — — — 10,981 — — 10,981 Public offering of common stock, net of issuance costs — — 14,545,454 15 74,620 — — 74,635 Private placement of pre-funded warrants, net of issuance costs — — — — 19,996 — — 19,996 Unrealized loss on investments — — — — — ( 209 ) — ( 209 ) Net loss — — — — — — ( 48,004 ) ( 48,004 ) Balance at March 31, 2024 2,761,108 $ 3 113,798,942 $ 114 $ 1,685,928 $ ( 194 ) $ ( 1,259,736 ) $ 426,115 Exercise of stock options, net of issuance costs — — — — ( 4 ) — — ( 4 ) Issuance of common stock upon vesting of restricted stock units — — 50,615 — — — — — Conversion of preferred shares to common stock — — — — — — — Stock-based compensation — — — — 9,630 — — 9,630 Public offering of common stock, net of issuance costs — — — — ( 104 ) — — ( 104 ) Unrealized gain on investments — — — — — ( 228 ) — ( 228 ) Net loss — — — — — — ( 38,427 ) ( 38,427 ) Balance at June 30, 2024 2,761,108 $ 3 113,849,557 $ 114 $ 1,695,450 $ ( 422 ) $ ( 1,298,163 ) $ 396,982 The following table summarizes the Company’s changes in stockholders’ equity accounts for the three and six months ended June 30, 2023 (in thousands, except share data): Convertible Common Additional Accumulated Accumulated Total Stockholders' Shares Amount Shares Amount Capital Gain (Loss) Deficit Equity Balance at December 31, 2022 2,794,549 $ 3 97,294,917 $ 97 $ 1,536,497 $ ( 1,854 ) $ ( 1,050,804 ) $ 483,939 Exercise of stock options, net of issuance costs — — 68,847 — 222 — — 222 Issuance of common stock upon vesting of restricted stock units — — 827,251 1 — — — 1 Stock-based compensation — — — — 10,983 — — 10,983 Unrealized gain on investments — — — — — 1,208 — 1,208 Net loss — — — — — — ( 18,881 ) ( 18,881 ) Balance at March 31, 2023 2,794,549 $ 3 98,191,015 $ 98 $ 1,547,702 $ ( 646 ) $ ( 1,069,685 ) $ 477,472 Exercise of stock options, net of issuance costs — — 24,940 — 81 — — 81 Issuance of common stock upon vesting of restricted stock units — — 139,558 — — — — — Conversion of preferred shares to common stock ( 33,441 ) — 167,205 1 — — — 1 Stock-based compensation — — — — 12,897 — — 12,897 Unrealized gain on investments — — — — — 59 — 59 Net loss — — — — — — ( 52,755 ) ( 52,755 ) Balance at June 30, 2023 2,761,108 $ 3 98,522,718 $ 99 $ 1,560,680 $ ( 587 ) $ ( 1,122,440 ) $ 437,755 |