Gossamer Bio (GOSS) shares jumped 44% on Monday after the company laid out a clear path to getting its lead drug candidate, seralutinib, in front of the FDA. The biotech also tidied up its balance sheet and regained full control of the drug's global rights — all without writing a big check.
The clinical-stage company said it will submit a New Drug Application (NDA) for seralutinib in September 2026, following a pre-NDA Type B meeting with the FDA in mid-June. The FDA characterized the treatment effect and statistical significance from the Phase 3 PROSERA study as review issues rather than filing hurdles — a meaningful distinction that suggests the agency sees the data as worth a closer look, not a dead end.
Gossamer plans to support the NDA with the Phase 3 data, plus confirmatory results from its Phase 2 TORREY study and other supportive analyses. If the FDA accepts the filing, a decision on approval for the pulmonary arterial hypertension (PAH) treatment could come in the third quarter of 2027.
Full Global Rights Reacquired From Chiesi
In a separate move, Gossamer and Chiesi agreed to end their collaboration, giving Gossamer complete operational control over development, pricing, manufacturing, and commercialization worldwide. Under the termination terms, Chiesi will make a one-time $5 million payment to Gossamer to settle existing and future obligations, including second-quarter 2026 costs. Gossamer made no upfront cash payment to reclaim the rights, but Chiesi will receive capped royalties on global net sales and specified milestone payments.
Debt Reduction And Financial Balance Sheet Updates
Stockholders approved proposals at a special meeting related to exchanging 5.00% Convertible Senior Notes due 2027. The transaction reduced the aggregate debt principal by approximately $115.9 million, bringing the remaining 2027 note balance down to $18.9 million. Shareholders also authorized a reverse stock split to support Nasdaq minimum bid price compliance. As of June 30, 2026, the company held preliminary cash, cash equivalents, and marketable securities of about $57 million.
Gossamer Bio shares were up 44.04% at $0.19 at the time of publication on Monday. The stock is trading near its 52-week low of $0.11.
