From one donor, thousands of doses: Meet the startup making cell therapy accessible

Living therapies, made of engineered immune cells – and capable of hunting down cancer, reversing autoimmune disease and fighting infections that antibiotics can’t touch – is a version of medicine most have never heard about. And yet, it exists. Some, with Food and Drug Administration (FDA) approval. 

The problem is that most people who need them will never get them. Not because the science doesn’t work, but because making these therapies is extraordinarily difficult – and the industry hasn’t solved it yet. 

ImmuneBridge, a San Francisco-based biotech company, is working to change that. This week, the company announced it’s ready to bring more of the industry along with it. 

A bottleneck holding back a revolution 

Cell therapy works by using living immune cells to fight disease in ways traditional drugs cannot. Such an approach has produced genuine breakthroughs, including patients with terminal cancers entering remission, and children with rare genetic disorders stabilized for the first time. 

However, these therapies come with an enormous practical burden: the most common approach – autologous therapy, which uses the patient’s own cells – can take over a month to produce from a single treatment for an individual. It requires collecting cells from an already-sick patient, modifying them in a lab, and re-infusing them, for which it cannot be mass produced. 

Although six autologous CAR-T cell immunotherapy products have been approved by the FDA since 2017, high levels of customization and lengthy manufacturing processes have limited widespread adoption. Meanwhile, high costs pose challenges in positioning it as a viable first-line treatment, according to biotech philanthropist Anshul Mangal. 

Allogenic therapy, which uses cells from healthy donors to create treatments that can be stored and used across several patients – is widely seen as the answer; think of it as the difference between a custom-tailored garment made from scratch for one person, and a well-designed one made in a range of sizes that fits thousands. 

But, allogeneic manufacturing has serious challenges of its own: the quality and composition of the donated cellular starting material are of paramount importance, and cells from different donors have different propensities for expansion – creating variability that can derail downstream processing. 

And when immune stem cells lose pluripotency in the lab, as often happens during replication, they become far less useful therapeutically, driving up costs and limiting how many doses can be produced per donor. 

With only two allogeneic cell therapies on the market so far, manufacturing remains fragmented, inconsistent, and economically misaligned. 

ImmuneBridge’s solution 

ImmuneBridge built a two-part platform to address these problems simultaneously. First, a machine learning-powered donor screening system – the first of its kind designed around specific diseases – identifies which donors are more likely to be effective upfront, rather than selecting them based on general health criteria with the hopes their cells perform well against a particular condition. 

This dramatically reduces the guesswork that has made early-stage cell therapy development slow and costly. 

The second component is the real breakthrough: a proprietary small molecule that preserves stem cell pluripotency even through multiple rounds of replication. With it, ImmuneBridge can produce thousands of therapeutic doses from a single donor – compared to the tens of doses most competitors can manage at best. 

These cells can then be developed into T cells for cancer, NK cells for autoimmune disorders, macrophages to treat liver fibrosis, neutrophils for severe infections, and more. 

The woman behind the mission 

ImmuneBridge’s new CEO, Dr. Nina Horowitz, didn’t come to this work through a career plan. She came through a hospital room. 

At eight years old, Horowitz was rushed to the emergency room with an ovarian teratoma – a rare tumor that can turn malignant. While she recovered, her experience shaped everything that followed. 

After earning her PhD from Stanford, she joined ImmuneBridge as head of research, built the startup’s donor screening system, and steadily rose to Chief Scientific Officer before being named CEO last year. 

“If you can’t make these therapies reliably and at scale, they won’t reach the people who need them. That’s the problem we’re trying to solve,” she said. 

Rui Tostoes, who was recently appointed Chief Technology Officer at ImmuneBridge, has spend his career designing cell therapy manufacturing systems. 

“At ImmuneBridge, we’re finally aligning the biology with the engineering, and we’re seeing true scalability as a result,” he added. 

Opening the doors 

Until now, ImmuneBridge’s platform was used exclusively for its own pipeline. That changed yesterday, upon the company’s announcement that it will offer external co-development partnerships to biotechs and pharma companies who want to build on the platform rather than starting one from scratch.  

Supporting the expansion is a second seed round of $7.7 million USD, led by NFX – a venture firm with over $1.5 billion USD under management, known for backing Lyft, DoorDash, and Mammoth Biosciences Pulse 2.0, – alongside One Way Ventures, M Ventures, Insight Partners, LongGame Ventures, T.Rx Capital, Healthspan Capital, Sand Hill Angles, and two independent investors. 

Total seed funding now stands at nearly $20 million USD. 

The market backdrop underscores the urgency: the global cell therapy market was estimated at $7.21 billion USD in 2025, and is projected to reach $55.72 billion USD by 2035, growing at a compound annual growth rate of 22.69%. 

Manufacturing capacity is widely cited as one of the key constraints of that growth – which is exactly where ImmuneBridge is planting its flag. 

“Manunfacturing is the difference between hypotheticals and saving lives,” said Semyon Dukach, founding partner of One Way Ventures. 

“ImmuneBridge is putting in place the systems that could make an entire class of therapies affordable and accessible.” 

ImmuneBridge currently partners with more than a dozen organizations, expects animal data later this year, and plans to begin human trials in 2028, with a goal of ten therapies in the clinic over the next decade. 

For Dr. Horowitz, the mission is simple: make sure that the next eight-year old who ends up in a hospital room has access to every tool medicine has to offer, regardless of where they live or what the treatment costs. 

Featured image: Courtesy of ImmuneBridge

Disclosure: This article mentions clients of an Espacio portfolio company.