Biotech financing in 2025 emphasized capital discipline over equity-led growth. With markets selective, companies leaned on debt, convertibles and non-dilutive funding to extend runways, refinance obligations and support late-stage development or commercial launches. These 10 financings stand out for their scale and for how strategically capital was deployed around key clinical, regulatory and commercial milestones.
10. BridgeBio
Type: Post-IPO
Date: February 2025
Amount raised: USD 563m
BridgeBio raised USD 563m through a post-IPO convertible note offering issued in February. The Palo Alto company planned to use the proceeds primarily to eliminate existing debt and reinforce its balance sheet, ending Q1 with substantial liquidity. This provided meaningful runway as BridgeBio continued to advance its pipeline and await USD 105m in milestone payments tied to ex-US approvals of BEYONTTRA.
9. Axsome Therapeutics
Type: Debt financing
Date: May 2025
Amount raised: USD 570m
Ahead of the June launch of its migraine drug, Symbravo, Axsome announced a USD 570m term loan and revolving credit facility with Blackstone, retiring a previous term loan with Hercules Capital. The deal lowers Axsome’s cost of capital and bolsters liquidity as it transitions into its next commercial phase, reinforcing its ability to self-fund launches and negotiate future partnerships from a position of strength.
8. Alnylam Pharmaceuticals
Type: Post-IPO
Date: September 2025
Amount raised: USD 575m
Alnylam raised USD 575m through an upsized convertible note offering, using the proceeds to refinance existing 2027 converts and extend its maturity profile. The transaction aids in limiting near-term dilution while preserving financial flexibility to support its growing RNAi commercial franchise and future partnering opportunities.
7. Moderna
Type: Grant
Date: January 2025
Amount raised: USD 590m
Moderna secured USD 590m in US government funding to accelerate development of mRNA-based influenza vaccines, focused particularly on bird flu. Awarded in the twilight of the Biden administration, the funding was subsequently withdrawn in May 2025 by the Department of Health and Human Services, citing the lack of testing for mRNA vaccines.
6. Kailera Therapeutics
Type: Private equity
Date: October 2025
Amount raised: USD 600m
Kailera Therapeutics raised USD 600m in a Series B financing led by Bain Capital Private Equity to advance its late-stage obesity pipeline. The round supports global Phase 3 trials of lead GLP-1/GIP agonist KAI-9531 and further development across oral and injectable programs, positioning Kailera as a well-capitalized private contender in the increasingly competitive obesity market.
5. Sarepta Therapeutics
Type: Post-IPO
Date: February 2025
Amount raised: USD 600m
Sarepta Therapeutics established its inaugural USD 600m senior secured revolving credit facility, providing non-dilutive contingent liquidity to support its long-term growth strategy. The facility enhances Sarepta’s financial flexibility as the company advances its rare disease portfolio and pursues strategic initiatives aligned with its Sarepta 2030 objectives.
4. Avidity Biosciences
Type: IPO
Date: September 2025
Amount raised: USD 690m
As the only IPO in this list, Avidity Biosciences raised USD 690m to advance its late-stage RNA therapeutics pipeline, including programs targeting Duchenne muscular dystrophy. The proceeds will support multiple potential launches, scales commercial capabilities and continued investment in Avidity’s proprietary AOC platform.
3. Cytokinetics
Type: Post-IPO
Date: September 2025
Amount raised: USD 729.5m
Cytokinetics entered a pivotal late-2025 inflection point as it approached the PDUFA date for aficamten in obstructive HCM. With regulatory reviews advancing across the US, Europe and China and commercial launch preparations underway, the company signaled readiness to transition to commercialization without near-term financing pressure, preserving strategic flexibility for partnering or expansion post-approval.
2. Abivax
Type: Post-IPO
Date: July 2025
Amount raised: USD 747.5m
Abivax completed a USD 747.5m post-IPO round to fund its lead ulcerative colitis program through a planned NDA submission. The raise provides multi-year runway into late 2027, materially de-risking development and positioning the company to approach potential partnering discussions from a position of financial strength as pivotal data mature.
1. Retro Biosciences
Type: Private equity
Date: January 2025
Amount raised: USD 1bn
Retro Biosciences raised a reported USD 1bn Series A in the largest biotech financing of 2025, led by OpenAI founder and CEO Sam Altman. The funding underwrites an ambitious longevity-focused R&D agenda, spanning cell reprogramming and age-related disease targets, and positions Retro as a well-capitalized, long-horizon player in the increasingly crowded longevity and rejuvenation space.