Cell therapy gets plenty of attention for its science: engineered immune cells that hunt tumors; treatments that can put terminal cancer patients into remission; therapies that address diseases conventional medicine has never been able to touch.
What gets talked about less is the part that happens before – the grinding, expensive, frequently failing process of actually making those cells in quantities large enough to treat people.
Such is the problem ImmuneBridge was built around. And this week, after years of developing its approach internally, the company said it’s ready to open it up.
The San Francisco biotech announced a second seed round of $7.7 million USD, led by NFX – the venture firm behind Lyft, DoorDash, and Mammoth Biosciences, with over $1.5 billion USD under management – alongside One Way Ventures, M Ventures, Insight Partners, LongGame Ventures, T.Rx Capital, Healthspan Capital, Sand Hill Angels, and two independent investors.
Total seed funding now sits at nearly $20 million USD. The raise also marks the single largest investment LongGame Ventures has made to date.
The capital will fund both ImmuneBridge’s internal pipeline and a new push to offer its platform to outside partners – biotech startups and pharmaceutical companies that want to develop allogeneic immune therapies without having to reinvent the manufacturing process to do it.
Why manufacturing has been such a wall
Allogeneic cell therapy – building treatments from healthy donor cells that can be stored and used across many patients rather than custom-made for each one – has long been considered the model that could make cell medicine genuinely scalable.
Autologous therapies, which require harvesting cells from the patient, modifying them, and re-infusing them, can take over a month per treatment, and cannot realistically be mass-produced. Allogeneic approaches promise to change the equation.
But the manufacturing reality has been messier than the theory. Donor cells don’t perform consistently, as their potency and expansion potential varies significantly from person to person – making reliable large-scale production difficult.
Beyond this, cells from different donors have differing propensities for expansion – and therefore different yields – thus creating inconsistencies that can derail downstream processing.
Then, there’s the pluripotency problem: immune stem cells cultured in a lab tend to lose the ability to develop into the specific cell types needed for therapy as they replicate. Once this happens, the cells become far less therapeutically useful – and far more expensive to work with. Most companies in the field can produce only tens of doses from a single donor.
The industry remains far from a repeatable, standardized manufacturing process which could support broader clinical and commercial deployment, with manufacturing fragmented, inconsistent and economically misaligned.
ImmuneBridge’s two-part fix
ImmuneBridge’s platform attacks both problems. First, the company uses a disease-specific donor screening system – the first of its kind – that uses machine learning to identify which donors’ cells are most likely to be effective against a particular condition.
Rather than selecting donors based on general health markers and hoping for the best, the system narrows the field at the earliest stage of development, curing waste and improving the odds of building something that actually works.
Second, the firm’s proprietary small molecule keeps stem cells pluripotent even after repeated rounds of replication – meaning that cells stay capable of developing into whatever immune cell type a given therapy requires, including T cells for cancer, NK cells for autoimmune disorders, macrophages for liver fibrosis, neutrophils for severe infections.
This twofold system allows the company to produce thousands – and more targeted – therapeutic doses from a single donor, compared to tens most competitors can manage.
“Cell therapy has incredible potential to further revolutionize the treatment of cancer and a number of other diseases, but manufacturing has been a huge impediment,” said Dr. Nina Horowitz, ImmuneBridge’s newly-appointed CEO.
“If you can’t make these therapies reliably and at scale, they won’t reach the people who need them.”
The people behind it
Horowitz didn’t arrive at this work through a career plan alone. At age eight, she was rushed to the ER with an ovarian teratoma – a rare tumor that can turn malignant. She recovered, however, and the experience quietly shaped her professional ambitions.
After her PhD from Stanford, she joined ImmuneBridge as head of research, built the donor screening system, rose to Chief Scientific Officer, and was named CEO last year.
Joining her as CTO is Rui Tostoes, who has spent his career on a single question: “How do we make these therapies cheaper and reliable enough to help everyone – not just a handful of patients?” he said. “At ImmuneBridge, we’re finally aligning the biotechnology with the engineering, and we’re seeing true scalability as a result.
The market waiting on the other side
The stakes for getting this right are considerable: the global cell therapy market was valued at $8.88 billion USD in 2025, and is projected to reach $190 billion USD by 2034, as per a March 2026 study.
Manufacturing capacity is consistently cited as one of the primary growth constraints. In other words, the one thing standing between the therapies being developed and the patients who could benefit from them.
“Manufacturing is the difference between hypotheticals and saving lives,” said Semyon Dukach, founding partner at One Way Ventures.
“ImmuneBridge is putting in place the systems that could make an entire class of therapies affordable and accessible.”
Conversely, Dr. Robert Lanfer, institute professor at MIR and executive chairman of T.Rx Capital, put it simply: “Every emerging field matures by strengthening its foundation. In cell therapy, that foundation is manufacturing.”
ImmuneBridge currently works with more than a dozen partners across multiple cell types, and is targeting ten therapies in the clinic over the next ten years. They expect animal efficacy data later this year, and have human trials penciled for 2028.
Featured image: Courtesy of ImmuneBridge
Disclosure: This article mentions clients of an Espacio portfolio company
