Biotechnology & drug discovery · Cancer immunotherapy
Granza Bio
A San Francisco biotech trying to turn the immune system's own cell killing machinery into a programmable drug platform. Founded in 2024 out of Oxford immunology research, it has raised about $7.6 million and remains preclinical, with no products, patents or registered trials found on the public record yet.
Two Ashwins and a landmine metaphor
In 2020, a team in Michael Dustin's lab at Oxford's Kennedy Institute of Rheumatology described something odd under a cryo-soft x-ray tomography beamline at the Diamond Light Source. Cytotoxic T cells, the immune system's assassins, were not just injecting toxic proteins into target cells through direct contact. They were also releasing free-floating packages, about 120 nanometers across, that could kill on their own.
Dustin called them supramolecular attack particles, or SMAPs. “If the cytotoxic proteins are like bullets in the CTL's arsenal then the SMAP is a bomb,” he told Oxford's Kennedy Institute in 2020.
Four years later, two of his former students turned that discovery into a company. Ashwin Nandakumar was studying oncology at Oxford when he needed help analyzing a prostate cancer dataset. A colleague pointed him to another Oxford PhD student with the same first name, Ashwin Jainarayanan, who was working in Dustin's lab on the biology of attack particles. “I reached out to a few friends asking to help me analyze this data,” Nandakumar told TechCrunch in 2024. “They said, ‘There's another guy with the name Ashwin, you should connect with him.’”
The delivery problem
Cell and gene therapy has spent the last decade proving biology can be reprogrammed. CAR T cells can hunt specific cancer antigens, mRNA can instruct cells to build a chosen protein, gene editing can rewrite DNA outright. What none of these approaches has fully solved is getting the therapy to the right tissue without triggering the immune system's defenses against the delivery vehicle itself.
Granza Bio's premise is that cytotoxic immune cells already solved a version of this problem, and that the SMAP is proof of it: a self-contained structure that carries cytotoxic cargo and can act independently once released. If that packaging can be engineered to carry a chosen cargo to a chosen target, the company argues, it could become a platform rather than a single drug. “With attack particles, we discovered a new feature of the immune system that has the potential to transform the therapeutic landscape,” Dustin said in the company's July 2024 funding announcement. “They offer the power of cellular therapies with the off-the-shelf ease of antibody-based drugs.”
From lab partners to co-founders
Nandakumar and Jainarayanan were initially headed toward large pharmaceutical companies after finishing their doctorates. Dustin's research changed their plans. Y Combinator's biotech partner, Surbhi Sarna, encouraged the two to apply to the accelerator. “That conversation changed our lives,” Nandakumar told TechCrunch. “We decided we're not joining Big Pharma. We're going to make our own Big Pharma.”
The two Ashwins entered YC's Winter 2024 batch, with Dustin joining as academic co-founder while remaining a professor of molecular immunology at Oxford and director of research at the Kennedy Institute. Jainarayanan has described the science in personal terms: “I find the human body to be a chaotic yet orderly, stochastic yet organised system of immense complexity and beauty,” he told the iGEM Foundation's blog in September 2024.
Granza incorporated on both sides of the Atlantic: Granza Bio Limited in the UK on January 19, 2024, registered at Oxford's Bioescalator incubator, and Granza Bio Corporation in Delaware, registered in California on July 29, 2024, from its San Francisco office. State filings list Nandakumar as chief executive, chief financial officer and a director, and Jainarayanan as secretary and a director.
A fast, oversubscribed seed
“Our plan initially was to raise $2.5 million to get very crucial experiments done,” Nandakumar told TechCrunch. “We started fundraising on [a] Wednesday and hit that target on a Friday.” Investor demand pushed the round bigger. On July 3, 2024, Granza announced an oversubscribed $7.14 million seed led by Felicis and Refactor, with participation from Y Combinator, Metaplanet, Zeno Ventures, Ritual Capital, Pioneer Fund, Oxford Angel Fund, North South Ventures, and a long list of angels, several former YC partners.
“The research out of Professor Dustin's lab is completely novel,” Felicis deal partner Tobi Coker told TechCrunch. Refactor's Zal Bilimoria said he looks for “technical founders who are experts in their fields,” and that “both Ashwins really fit that perfectly.”
What is proven, and what is still claimed
| Evidence | What the record shows | Source type |
|---|---|---|
| Founding discovery | Balint et al., Science, May 2020, from Dustin's Oxford lab, describing SMAPs as ~120 nanometer particles with a thrombospondin-1 shell around a cytotoxic core. Published four years before Granza was founded and does not list either Ashwin as an author. | Public record |
| Company platform paper | Jainarayanan, Dustin and 30 coauthors, posted a bioRxiv preprint on November 12, 2025, not yet peer reviewed. It reports a chromatography method to isolate SMAPs from NK-92 cells and shows purified SMAPs slowed growth of melanoma and pancreatic tumors injected into mice. Its competing interest statement discloses: “AJ and MLD are co-founders of Granza Bio Ltd.” | Public record |
| Patents | No issued or published patent application naming Granza Bio, Nandakumar, Jainarayanan or Dustin for this platform was found. | Not found |
| FDA record | No 510(k), PMA or IND-related filing found, consistent with a preclinical company. | Not found |
| Registered clinical trials | No ClinicalTrials.gov entry found for Granza Bio as of September 25, 2026. | Not found |
| Platform framing | The July 2024 release described “precision delivery shells” carrying outside cargo. An October 2026 conference listing describes the SMAP-T platform as reprogramming T cells in vivo to enhance their own cytotoxic function. Both company-stated; the emphasis has shifted. | Company-stated |
| Revenue estimate | GetLatka lists an estimated $5 million in 2024 revenue reached in June 2024, a month before the seed round even closed, and separately says the company raised “$0” and was founded in 2023. Both conflict with the company's own release and with the filing dates; no revenue-generating product appears in any other source. | Differs from other records |
Read plainly, the biology underneath Granza is real and independently published: SMAPs are a documented feature of cytotoxic T cells years before the company existed. What is still a bet is whether that biology can become a repeatable platform. The November 2025 preprint is the first public data tying Granza's founders to purified SMAPs slowing tumor growth in mice, and it is a preprint, not a peer-reviewed publication, a clinical result or a cleared product.
What to watch
- Whether the November 2025 bioRxiv preprint clears peer review, and in what journal.
- Any IND filing or first clinical trial registration.
- A named Series A round, following the oversubscribed 2024 seed.
- Whether the company files a patent application tied to the SMAP-T platform.
- Named pharma partnerships or licensing deals, none reported yet.
In their words
“If the cytotoxic proteins are like bullets in the CTL's arsenal then the SMAP is a bomb.”
Mike Dustin, director of research, Kennedy Institute of Rheumatology, Oxford, May 2020 · Independent
“We decided we're not joining Big Pharma. We're going to make our own Big Pharma.”
Ashwin Nandakumar, co-founder and CEO, TechCrunch, July 2024 · Independent
“We started fundraising on [a] Wednesday and hit that target on a Friday.”
Ashwin Nandakumar, TechCrunch, July 2024 · Independent
“With attack particles, we discovered a new feature of the immune system that has the potential to transform the therapeutic landscape.”
Michael Dustin, co-founder, company funding release, July 2024 · Company release
“Through the development of a comprehensive library of engineered shells, we aim to tackle the challenges of tropism, immunogenicity, and stability head-on.”
Ashwin Jainarayanan, co-founder and CSO, company funding release, July 2024 · Company release
“I find the human body to be a chaotic yet orderly, stochastic yet organised system of immense complexity and beauty.”
Ashwin Jainarayanan, iGEM Foundation blog interview, September 2024 · Interview
“The research out of Professor Dustin's lab is completely novel.”
Tobi Coker, deal partner, Felicis, TechCrunch, July 2024 · Investor
Related companies
Sources
- Public recordBalint et al., Supramolecular attack particles are autonomous killing entities released from cytotoxic T cells
- Public recordJainarayanan et al., Isolation of functional supramolecular attack particles (SMAPs)
- Public recordGranza Bio Corporation, California filing record
- Public recordGranza Bio Limited, company filing history
- IndependentNew weapon identified in arsenal against disease
- IndependentGranza Bio grabs $7M seed from Felicis and YC to advance delivery of cancer treatments
- InterviewIn Conversation with the Co-Founder of Granza Bio: From Lab Partners to Biofounders
- IndependentGranza Bio 2026 Company Profile: Valuation, Funding & Investors
- IndependentGranza Bio Funding Rounds & List of Investors
- InvestorGranza Bio: Reengineering How Medicine Reaches the Body
- UnreliableGranza Bio Revenue 2024: $5M Est. ARR
- CompanyGranza Bio Raises $7M+ Seed Funding to Advance the Delivery of Cancer Treatment and Genetic Medicines
- CompanyGranza Bio company page and launch post
- CompanyGranza Bio website and newsroom
- CompanyGranza Bio company presentation
Profile researched and written by Healthcare Discovery. Last updated September 29, 2026.
