Avidity Biosciences, Inc. SEC Filings

Avidity Biosciences insider activity: The Chief Commercial Officer executed simultaneous option exercises and share sales on 10/03/2025. The reporting person exercised a stock option with a $9.05 exercise price to acquire 6,562 shares and immediately sold 6,562 shares under a Rule 10b5-1 trading plan adopted on 09/11/2024. The sales produced a weighted-average price of $45.3781 (sales ranged $44.80–$47.21), and the reporting person’s beneficial ownership after the transactions is 55,000 shares (with 177,188 shares underlying outstanding options).

Avidity Biosciences insider Steven George, the company's Chief Medical Officer, reported option exercises and a contemporaneous sale on 09/22/2025 under a previously adopted Rule 10b5-1 trading plan. He exercised a stock option with a $10.16 exercise price for 2,208 shares, increasing his underlying option holdings by 2,208 shares exercisable through 01/19/2034 and resulting in total beneficial ownership of 70,667 shares. Simultaneously, 2,208 common shares were sold at $40.58, leaving him with 41,075 shares owned directly after the transactions. The filing states the 10b5-1 plan was adopted on 06/12/2024 and the option grant date was 01/20/2024.

Teresa McCarthy, Chief Human Resources Officer of Avidity Biosciences, reported option exercise and a contemporaneous sale on 09/15/2025. She exercised 15,000 stock options at an exercise price of $22.34, which increased her total reported beneficial ownership of common stock to 112,130 shares. On the same date she sold 15,000 shares for a weighted-average price of $41.4095, leaving 97,130 shares reported beneficially owned. The transactions were executed under a Rule 10b5-1 trading plan adopted 04/11/2025. The option shares are fully vested and the option grant shows 85,000 derivative shares remaining.

Steven George Hughes, Chief Medical Officer of Avidity Biosciences, Inc. (RNA), reported exercises and a sale on 09/15/2025 under a previously adopted Rule 10b5-1 trading plan. He exercised 1,542 stock options with an exercise price of $6.57 and simultaneously sold 1,542 shares at $45.41. Following the reported transactions, the Form shows 38,867 shares beneficially owned as direct holdings in the non-derivative table and 49,333 derivative securities (options) beneficially owned in the derivative table. The options vest monthly (1/48th) beginning 09/11/2023 and fully vest on the fourth anniversary, subject to continued service. The transactions were effected under a 10b5-1 plan adopted 06/12/2024.

Avidity Biosciences (RNA) filing a Form 144 notifies the proposed sale of 20,000 common shares held by a person for whose account the sale is to be made. The shares were acquired on 09/11/2025 by exercise of stock options from the issuer and paid for in cash on the same date. The aggregate market value of the proposed sale is reported as $928,000.00 and the issuer's outstanding shares are listed as 128,653,337. The sale is expected to occur on or about 09/11/2025 through NASDAQ via Morgan Stanley Smith Barney LLC Executive Financial Services. The filing states there were no securities sold by the person in the past three months.

Avidity Biosciences, Inc. discloses parts of a prospectus supplement for debt and equity-related offerings and clinical program updates. The document notes clinical experience from EXPLORE44 and EXPLORE44-OLE for the candidate del-zota, where participants previously dosed with 5 mg/kg Q6W or 10 mg/kg Q8W were transitioned to 5 mg/kg Q6W; pooled functional data versus a DMD44 natural history cohort showed improvement for non-ambulatory participants (natural history N=27; del-zota N=17). The filing references pre-funded warrants outstanding as of June 30, 2025 with an exercise price of $0.001 per share and potential dilution if exercised or if additional capital is raised. It discloses an ATM facility entered August 9, 2024 with TD Securities as sales agent and a 45-day lock-up period before ATM sales, plus customary lock-up exceptions. The prospectus cites various prior SEC filings for further detail.

Avidity Biosciences reported strongly positive one‑year data for its Duchenne muscular dystrophy therapy candidate delpacibart zotadirsen (“del-zota”) from the EXPLORE44 and EXPLORE44-OLE trials. Participants showed approximately 25 percent of normal dystrophin production, with total dystrophin restored up to 58 percent of normal, and creatine kinase levels reduced by greater than 80 percent and maintained near normal for up to 16 months.

Across multiple functional tests, del-zota patients improved or remained stable while matched natural history groups worsened, including better performance in stair climbing, walking/running, time to rise, and upper limb function. Del-zota demonstrated favorable long-term safety, with mostly mild or moderate adverse events and one discontinuation for hypersensitivity. Avidity plans to submit a Biologics License Application to the FDA at year end 2025, the first of three planned BLA submissions over a 12‑month period. The board also increased shares reserved under the 2022 Employment Inducement Incentive Award Plan from 4,500,000 to 8,000,000.

Avidity Biosciences director Troy Edward Wilson executed option exercises and share sales under a Rule 10b5-1 plan on 09/05/2025. He exercised 14,500 stock options with a $12.48 exercise price, resulting in acquisition of 14,500 common shares. On the same date he sold 14,500 shares and 15,000 shares at $50.00 per share pursuant to the plan. Following these transactions his direct beneficial ownership is reported as 54,425 shares and he holds 13,711 shares indirectly through a family trust. The reporting person adopted the 10b5-1 plan on December 4, 2024, and the option was fully vested as of the transaction date. The Form 4 was signed by an attorney-in-fact on 09/09/2025.

Avidity Biosciences director and CEO Sarah Boyce exercised 50,000 vested stock options at an exercise price of $1.24 and concurrently sold 50,000 common shares on 09/05/2025. The sales produced a weighted-average sale price of $49.9487 per share, with sale prices in the range $49.76 to $50.12. After these transactions, Ms. Boyce directly beneficially owns 305,871 shares and holds derivative rights to 50,000 shares exercisable through 12/17/2029, for a total direct beneficial ownership reported as 1,022,015 derivative-linked shares and 355,871 pre-transaction common shares as shown on the Form 4. The option exercise and sales were executed under a Rule 10b5-1 trading plan adopted August 15, 2024.