aibioGossamer Bio launches exchange offer for 5.00% convertible notes
Tickers GOSS
The offer would swap $200 million of 2027 notes for new 7.50% secured convertible notes due 2030, plus shares or prefunded warrants.
Key facts
- Company
- Gossamer Bio, Inc. (NASDAQ: GOSS)
- News type
- Debt Financing
- Primary source
- SEC filing
The exchange offer
Gossamer Bio, Inc. announced on May 18, 2026 that it has started an exchange offer and consent solicitation for its 5.00% Convertible Senior Notes due 2027. The company says $200 million of principal is outstanding on those notes. The offer was announced in the first quarter results release, filed as Exhibit 99.1 to a Form 8-K. It is open only to qualified institutional buyers. The early tender deadline is expected 10 business days after commencement, and the offer is expected to expire 21 business days after commencement unless extended.
For each $1,000 of principal tendered, holders receive 1,588.2353 shares of common stock or prefunded warrants, plus $360 of principal in new notes. Notes tendered before the early tender deadline also receive 750 purchase warrants. The offer requires 98% participation, and the company may waive that threshold. Holders of about 75.2% of the existing notes have signed a transaction support agreement to tender.
The new notes are 7.50% senior secured first lien convertible notes. Interest is paid semi-annually in cash. They mature on July 1, 2030, and are secured by a first-priority lien on substantially all assets of the company and its subsidiaries. The proposed amendments would remove substantially all restrictive covenants and certain events of default in the indenture for the existing notes. The new notes would convert at an initial price set at a 10% premium to a reference price, and the purchase warrants would have an exercise price at a 25% premium to a reference price and be exercisable from six months after issuance through the fifth anniversary. The new notes would carry a minimum cash covenant of $40 million. The company says full participation would cut its convertible debt from $200 million to $72 million. The release names Cantor Fitzgerald & Co. as dealer manager and Latham & Watkins LLP as legal counsel to the company for the exchange offer. It names no placement agent or other advisor.
The drug and the regulatory path
Gossamer describes itself as a clinical-stage biopharmaceutical company developing seralutinib, an inhaled PDGFR, CSF1R and c-KIT inhibitor, for pulmonary arterial hypertension and for pulmonary hypertension associated with interstitial lung disease.
The company says it has confirmation of an in-person Pre-NDA Type B meeting with the FDA, scheduled for mid-June. It switched from a planned Type C meeting to a Type B meeting after continued review of the PROSERA dataset. The 10-K filed in March, after the February 2026 topline PROSERA results, said the company was still seeking FDA feedback to define a regulatory path, had paused enrollment in the SERANATA study, and was evaluating its strategic options and resource allocation. The company says it expects to submit an NDA for PAH in September 2026, and that it is pursuing one adequate and well-controlled trial plus confirmatory evidence. The release says approval could come in the third quarter of 2027 if the NDA is accepted, while the 10-K anticipated a potential approval action date by year end 2027.
The company's imaging claims rest on an exploratory substudy. The PROSERA CT functional respiratory imaging substudy enrolled 162 patients, and the company says it saw multiple statistically significant exploratory effects. The release says all reported p-values were nominal and not adjusted for multiple comparisons. The release does not report the primary PROSERA result, and it calls the imaging findings exploratory.
Losses and cash
The 10-K filed March 17, 2026 reports revenue of $48.5 million for 2025, against $114.7 million for 2024. Research and development expense was $174.1 million in 2025, against $138.5 million in 2024. The net loss was $170.4 million in 2025, against $56.5 million in 2024. Cash used in operations was $171.3 million in 2025, against $3.5 million in 2024.
The company reported cash, cash equivalents and marketable securities of $99.2 million as of March 31, 2026, down from $136,932 thousand at December 31, 2025, and a first-quarter net loss of $46.7 million. It says that cash should fund operations into the first quarter of 2027. At March 31 total liabilities were $290,382 thousand against total assets of $128,899 thousand, with a stockholders' deficit of $161,483 thousand.