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Gossamer Bio, Inc. (GOSS), a Delaware biotechnology corporation, filed a new notice of an exempt securities offering under Regulation D, Rule 506(b).
The offering involves options, warrants or other rights to acquire securities and the securities issuable upon exercise. The company reports that $25,000,000 of securities have been sold and that $125,000,000 remain available to be sold. The date of first sale is listed as August 20, 2026. Leerink Partners LLC and Cantor Fitzgerald & Co. are identified in the sales compensation section, and stated finders’ fees are $0.
Gossamer Bio, Inc. (GOSS) is calling a virtual special stockholder meeting to approve, under Nasdaq Listing Rules 5635(c) and 5635(d), a large potential issuance of Common Stock tied to an August 20, 2026 private placement. The financing includes Initial Closing pre-funded warrants already sold for aggregate gross proceeds of $25.0 million, plus a Second Closing tied to FDA acceptance of Gossamer’s NDA for seralutinib in pulmonary arterial hypertension that is expected to provide an additional $125.0 million of gross proceeds, excluding any FDA Approval Warrant exercises.
If stockholders approve Proposal 1, multiple series of convertible Preferred Stock, Pre-Funded Warrants and FDA Approval Warrants could convert or be exercised into up to an aggregate of approximately 1,606,953,812 shares of Common Stock, compared with 488,846,722 shares outstanding as of August 25, 2026, significantly diluting existing holders and creating substantial resale overhang. Approval would also remove a separate liquidation preference on the Preferred Stock and allow automatic conversion into Common Stock, while failure to approve would leave the Preferred Stock outstanding with its liquidation preference, restrict Gossamer’s ability to issue additional equity and could cause the Second Closing commitments to terminate after December 31, 2026.
Gossamer Bio, Inc. (GOSS) reports that its Board of Directors approved an amendment and restatement of the company’s bylaws, effective September 3, 2026. The Amended and Restated Bylaws reduce the stockholder meeting quorum requirement from holders of a majority to holders of one third (1/3) in voting power of the company’s capital stock issued and outstanding and entitled to vote, present in person, by remote communication if applicable, or represented by proxy, unless a higher threshold is required by law, the certificate of incorporation, or the bylaws.
Gossamer Bio, Inc. (GOSS) reported that executive officer Christian Waage, EVP, Tech Ops and Admin, received a grant of stock options covering 2,900,026 shares of common stock at an exercise price of $0.175 per share. The options expire on 2036-08-23 and vest based on future milestones and service conditions tied to FDA approval of seralutinib or, if approval is delayed, over time following the second anniversary of the grant date.
Gossamer Bio, Inc. (GOSS) reported a Form 4 for Chief Development Officer Caryn Peterson showing a grant of stock options for 5,800,051 shares of common stock on 2026-08-24, at an exercise price of $0.175 per share, expiring on 2036-08-23.
According to the vesting terms, 50% of the option vests upon FDA approval of seralutinib. The remaining 50% then vests in 24 equal monthly installments after that approval, subject to continued service. If FDA approval has not occurred within two years of the grant date, the entire option instead vests in 24 equal monthly installments starting two years after the grant date, also subject to continued service.
Gossamer Bio, Inc. (GOSS) reported that Chief Commercial Officer Robert Paul Smith Jr. received a stock option grant for 5,800,051 shares of common stock on August 24, 2026. The option has an exercise price of $0.175 per share and expires on August 23, 2036. According to the vesting terms, 50% of the shares vest upon FDA approval of seralutinib, and the remaining 50% vest in 24 equal monthly installments after that approval, subject to continuous service. If FDA approval has not occurred within two years of the grant date, vesting instead begins in 24 equal monthly installments starting two years after the grant date, also subject to continued service.
Gossamer Bio, Inc. (GOSS) reported that its COO/CFO, Bryan Giraudo, acquired derivative securities. A family trust received 25 Pre-Funded Warrants, each initially exercisable for Series A-1 non-voting convertible preferred stock at an exercise price of $0.0001 per share, with no expiration date. Each Series A-1 share is automatically convertible, upon stockholder approval under applicable Nasdaq rules for the related private placement, into common stock equal to $1,000 divided by $0.14, subject to beneficial ownership limitations.
Separately, Giraudo was granted a stock option over 5,800,051 shares of common stock at an exercise price of $0.175 per share, expiring on August 23, 2036. According to the vesting terms, 50% of the option vests upon FDA approval of seralutinib, and the remaining 50% vests in 24 equal monthly installments after that approval; if such approval has not occurred within two years of grant, vesting shifts to 1/24th monthly beginning two years after grant, in each case subject to his continuous service.
Gossamer Bio, Inc. (GOSS) reported that President & CEO Faheem Hasnain acquired two derivative awards. A family trust received 166 Pre-Funded Warrants exercisable at $0.0001 per share into Series A-1 preferred stock, which is automatically convertible after stockholder approval into common stock per a $1,000 ÷ $0.14 formula. Separately, Hasnain was granted 5,800,051 stock options for common stock at an exercise price of $0.175 per share, expiring in 2036, with vesting tied primarily to FDA approval of seralutinib or, failing that by two years after grant, a monthly time-based vesting schedule.
Gossamer Bio, Inc. (GOSS) reported that on August 24, 2026 it amended its amended and restated certificate of incorporation in connection with the closing of a previously announced private placement. The company filed a Certificate of Designation of Preferences, Rights and Limitations of Series A-1 Convertible Preferred Stock with the Delaware Secretary of State, formally creating this preferred stock series.
The rights and preferences of the Series A-1 Convertible Preferred Stock are described in a prior report under Item 1.01 filed on August 21, 2026 and are further detailed in the Certificate of Designation attached as Exhibit 3.1 to this report.
Gossamer Bio, Inc. (GOSS) is the subject of an Amendment No. 3 to a Schedule 13D filed by investment entities associated with D. E. Shaw. The amendment updates the description of these entities and restates their beneficial ownership and control relationships in Gossamer Bio’s common stock.
Based on 488,846,722 common shares outstanding as of August 8, 2026, D. E. Shaw Valence Portfolios, L.L.C. holds 27,698,267 shares, or 5.7%, and D. E. Shaw Cogence Portfolios, L.L.C. holds 1,429,927 shares, or 0.3%. Through advisory and management roles, D. E. Shaw & Co., L.P., D. E. Shaw & Co., L.L.C., related corporate entities, and David E. Shaw may be deemed to share voting and dispositive power over 29,128,194 shares, or 6.0%, while each disclaims direct beneficial ownership.