Funding profile · Preclinical drug discovery platforms

Parallel Bio

A human immune organoid platform reporting nearly $30 million raised. It has never filed a Form D of its own. The only SEC record is two third party vehicles holding $377,000.

$21.0MSeries A, announced June 12, 2025, led by AIX Ventures
$4.3MSeed, announced December 20, 2022, led by Refactor Capital
~$30MTotal raised to date, company-reported (June 2025)
$377KTotal on record at the SEC, across two syndicate vehicles

Data as of September 22, 2026. Company-reported figures are labeled.

Rounds at a glance

When Round Amount Investors Source
2021 Y Combinator, Summer 2021 $125,000 Y Combinator Reported
Oct 2021 Gaingels syndicate vehicle $127,000 18 investors · Gaingels Management LLC Form D
Dec 2022 Seed $4.3M Led by Refactor Capital; Breakout Ventures, Jeff Dean, Y Combinator, unnamed funds and pharma executives Company release
Mar 2023 Sydecar series vehicle $250,000 2 investors · administered by Sydecar LLC Form D
Jun 2025 Series A $21.0M Led by AIX Ventures; new: Amplo, Marc Benioff. Existing: Metaplanet, Humba Ventures, Atypical Ventures, Undeterred Capital, Jeff Dean Company release
To date Cumulative Nearly $30M Not itemised Company-stated
2021 to 2026 Federal grants $0 No NIH or NSF award found under the company name Not found

What the filings show

GAINGELS PARALLEL BIO LLC · Form D · filed Oct 29, 2021

First sale
Oct 21, 2021
Offered
$127,000 equity
Sold
$127,000 · $0 remaining
Investors
18 · average about $7,056
Minimum accepted
$2,000
Exemption
Rule 506(b)
Entity
Vermont LLC formed 2021 · industry group reported as Other
Related persons
David Beatty, executive officer, manager of Gaingels Management LLC, which is manager of the issuer
Filing
SEC EDGAR, CIK 0001889738

Parallel Bio Feb 2023 a Series of CGF2021 LLC · Form D · filed Mar 16, 2023

First sale
Mar 7, 2023
Type
Pooled investment fund, not reported as a venture capital fund
Offered
$250,000
Sold
$250,000 · $0 remaining
Investors
2 · average $125,000
Proceeds to expenses
$4,902, described as fund organizational and operating expenses
Exemptions
Rule 506(b); Investment Company Act 3(c)(1)
Related persons
Sydecar LLC (administrator); Taylor Hughes (officer of the administrator)
Filing
SEC EDGAR, CIK 0001969093

Reading the filings

  1. The company itself has filed nothing.An EDGAR company search for Parallel Bio returns only the Sydecar series. Neither the $4.3 million seed nor the $21 million Series A has a Form D behind it. Issuers selling under Section 4(a)(2) rather than Regulation D file none at all, so the absence is legal and common. It also means both announced rounds carry no filed amount, investor count or date that can be checked against the press release.
  2. What is filed is 1.3 percent of what is claimed.The two vehicles total $377,000 across 20 investors. Against the nearly $30 million the company reports raising, that is about 1.3 percent. Anyone treating EDGAR as the ledger for this company will be looking at a rounding error.
  3. The first outside money arrived 14 months before the seed was announced.The Gaingels vehicle records its first sale on Oct 21, 2021, two months after the Summer 2021 demo day. The seed was announced on Dec 20, 2022, so a round presented as a single $4.3 million event spans at least fourteen months of closings.
  4. Two very different investor profiles.The Gaingels vehicle took $127,000 from 18 people, about $7,056 each against a $2,000 minimum: an angel syndicate. The Sydecar series took $250,000 from 2 investors, $125,000 each. That second filing lands three months after the seed was announced, which fits an allocation syndicated after the round was declared closed rather than money that built it.
  5. Fees are thin and disclosed.Neither vehicle reports a sales commission or a finders fee. Only the Sydecar series reports proceeds used for anything other than the investment: $4,902, about 2.0 percent of the raise, for fund organisational and operating expenses.
  6. No non-dilutive capital.NIH and NSF award searches return no grant to this company; the name matches are ParAllele BioScience, an unrelated genomics firm funded by NHGRI in 2002 to 2005. For a platform selling into a federal policy shift, every dollar so far has been equity.

Commercial signals

Signal Detail Source type
Partners Eight pharmaceutical partners, three Fortune 500, testing more than 50 drugs. Same figures in June 2025 and June 2026. Company-stated
Named customer Centivax, for the Centi-Flu universal influenza candidate. The only partner ever named. Partner-stated
Downstream validation Centivax dosed its first Phase 1A participants in Australia on Feb 12, 2026 and reported full enrolment of 180 subjects in September 2026. Independent
Intellectual property Three published patent families naming Robert M. DiFazio, priority Jul 2022 and Jan 2024, assigned to Parallel Biosystems, Inc., active across seven jurisdictions. No granted US patent found. Public record
Regulatory environment FDA roadmap on reducing animal testing, April 2025, year one goals reported met April 2026. FDA Modernization Act 3.0 passed the Senate Dec 2025 and the House July 2026. Public record
Published evidence No peer-reviewed paper or preprint from the company found as of Sep 22, 2026. Not found
Headcount Team of 20 per the Y Combinator profile, against a Series A plan for roughly 30 scientists and engineers. Company-stated

What to watch

  • A Form D under Parallel Bio’s own name, the first filed disclosure of an offering amount and investor count.
  • A Series B. The Series A funded a team of about 30, and the company has since said it intends to develop its own drugs, a far more expensive plan.
  • The Centi-Flu Phase 1A readout, the first outside test of a platform prediction against human data.
  • Whether any partner other than Centivax is named, or contract values disclosed.
  • Enactment of FDA Modernization Act 3.0 and the interim final rule it would require within one year.

The Parallel Bio story on Healthcare DiscoveryHealthcare Discovery

Related companies

  • Adventris Pharmaceuticals: Shared investor: Refactor. A Baltimore startup built around a mutant KRAS peptide vaccine licensed out of Johns Hopkins
  • 64x Bio: Shared investor: Refactor. A Harvard spinout that engineers the cells which manufacture viral vectors, rather than the therapies those vectors carry
  • Ochre Bio: Shared investor: Gaingels. An Oxford company that designs RNA drugs and tests them in whole human donor livers kept alive on machines
  • Dorian Therapeutics: Shared investor: Gaingels. A Stanford spinout that built small molecule blockers of USP16, the enzyme that strips a silencing mark off histone H2A, and pointed them at the arthritic knee

Sources

  1. Public recordForm D, GAINGELS PARALLEL BIO LLCSEC · Oct 29, 2021
  2. Public recordForm D, Parallel Bio Feb 2023 a Series of CGF2021 LLCSEC · Mar 16, 2023
  3. Public recordEDGAR company search, form type DSEC · Sep 22, 2026
  4. Public recordPatent families CA3262226A1, WO2025155725A1, TW202546219AGoogle Patents · Sep 22, 2026
  5. Public recordNIH and NSF award searches, no company recordNIH, NSF · Sep 22, 2026
  6. IndependentParallel Bio is putting the immune system in a dishFierce Biotech · Aug 30, 2021
  7. IndependentParallel Bio’s $21M Series ADrug Discovery and Development · Jun 17, 2025
  8. IndependentSenate clears FDA Modernization Act 3.0Drug Discovery and Development · Dec 17, 2025
  9. IndependentCentivax fully enrols 180 subject flu vaccine trialSynBioBeta · Sep 22, 2026
  10. CompanyParallel Bio secures $4.3 million seed roundBusiness Wire · Dec 20, 2022
  11. CompanyParallel Bio secures $21 million in Series ABioSpace · Jun 12, 2025
  12. CompanyBay Area headquarters announcementBioSpace · Jun 16, 2026
  13. CompanyY Combinator company profileY Combinator · Sep 22, 2026

Compiled from SEC, FDA, NIH, NSF and patent office public records and published reports as of September 22, 2026. Form D notices report offerings under Regulation D; amounts reflect the filing date and may not capture later sales. Healthcare Venture Capital Fund holds no position in Parallel Bio. This page is not an offer to sell or a recommendation to buy any security.