Funding profile · Cell and gene therapy manufacturing

64x Bio

Two disclosed rounds totalling $59.5 million, the last one closed in January 2022, and no Form D on file at the SEC under either the trading name or the corporate name.

Data as of September 23, 2026. Company-reported figures are labeled.

Rounds at a glance

What the filings show

Reading the filings

1. The absence of a Form D is normal, not a flag.A company that sells securities under Section 4(a)(2) rather than Regulation D files no Form D at all. Roughly $59.5 million moved with no notice at the SEC, which means both rounds were almost certainly structured that way. It also means the investor counts, the amounts actually sold and the named related persons that a Form D would disclose are not on the public record for this company.
2. The corporate name is the one to search.The USPTO assignment on the granted patent reads 64-X, Inc., San Francisco, CA. That is the entity name any future Form D, financing statement or acquisition filing would carry. Searching only for 64x Bio misses it.
3. The arithmetic on the reported total closes.$4.5M plus $55.0M is $59.5M. GEN reported in June 2025 that the company had raised “over $59 million in seed funding”, which is the same figure with the round labels blurred. That implies no material third round between January 2022 and the middle of 2025.
4. Fifty six months on one Series A.From the January 2022 close to September 2026 is four years and eight months with no announced round. The company said at the Series A it planned to go from about ten employees to fifty within the year. Whether it did, and what that did to the burn rate, is not on the record.
5. The seed investors stayed for the A.First Round Capital, Fifty Years and Refactor Capital led the 2020 seed and all three appear again in the 2022 Series A. Insider participation of that shape usually means the technical milestones were met. Lifeforce Capital led the A and took the one board seat that is publicly identified, held by general partner Sander Duncan.
6. Cost was the whole thesis, and cost is now the field’s stated problem.That is the favourable reading. The unfavourable one is that between the Series A and the first product launch, Biogen, Vertex, Pfizer and Takeda all stepped back from AAV. A tools company is only worth what its customers can spend.

Commercial signals

What to watch

• A first Form D under 64-X, Inc. It would be due within 15 days of a first sale if a future round uses Regulation D.
• A named paying customer, as distinct from a collaboration to evaluate.
• Stable producer cell lines. Both shipped products are transient.
• Continuation filings in the mammalian and insect cell families, which would show where the company thinks the durable claims are.
• Any change in the Charles River relationship, the only third party commercial tie on the record.

The 64x Bio story on Healthcare DiscoveryHealthcare Discovery

Related companies

• Culture Biosciences: Shared investor: Boxgroup. A cloud lab that ran other companies’ fermentation for them, now selling the bioreactor itself through Cytiva
• Able Health: Shared investor: Lifeforce Capital. A Y Combinator company that turned Medicare’s quality reporting rules into software for medical groups
• Parallel Bio: Shared investor: Refactor. Miniature human lymph nodes, grown from donated tissue and run side by side across hundreds of donors, used to test drugs and vaccines before anyone takes them
• Notable Labs: Shared investor: First Round. A blood cancer company that screened drugs against a patient’s own cells to predict who would respond, in-licensed a shelved Boehringer Ingelheim compound, reached

Sources

1. Public recordUS Patent 12,241,062, assignee 64-X, Inc.USPTO · Mar 4, 2025
2. Public recordUS Patent Applications 2024/0052341 and 2025/0197884USPTO · 2024 and 2025
3. Public recordEDGAR company search and full text search, no registrant and no Form DSEC · checked Sep 23, 2026
4. Public recordNIH RePORTER project search, no awardNIH · checked Sep 23, 2026
5. Independent64x Bio Raises $55M To Advance Gene Therapy PlatformCrunchbase News · Jan 19, 2022
6. IndependentHarvard offshoot 64x Bio nets $55M in series A funding to expand cell production techFierce Pharma · Jan 19, 2022
7. IndependentAt BIO, Companies Launch New Products for AAV Manufacturing, AI Drug DiscoveryGEN · Jun 20, 2025
8. IndependentIs AAV gene therapy at a turning point?Drug Discovery News · Oct 23, 2025
9. Company64x Bio Emerges from Stealth, with seed round detailBusiness Wire, via BioSpace · Nov 16, 2020
10. Company64x Bio Raises $55 Million Series A Financing, with full investor listBusiness Wire · Jan 19, 2022
11. PartnerCharles River Announces Inaugural Advanced Therapy Incubator Program CohortCharles River Laboratories · Apr 29, 2025
12. Investor64x, seed round co-lead noteFifty Years News · Jan 19, 2022

Compiled from SEC, USPTO and NIH public records and published reports as of September 23, 2026. No Form D notice has been filed for this company; amounts shown are as reported by the company and by the press. Healthcare Venture Capital Fund holds no position in 64x Bio. This page is not an offer to sell or a recommendation to buy any security.