BioPharma, Pharma

Regeneron Jumps Into Cell Therapy via Alliance With Treg Startup Sonoma Bio

Regeneron is paying Sonoma Biotherapeutics $75 million to begin a partnership focused on developing cell therapies based on regulatory T cells, or Tregs. Each company brings technological capabilities to the alliance, which is initially focused on ulcerative colitis and Crohn’s disease.

Regeneron Pharmaceuticals already has a presence in immunology, but nothing in its portfolio or pipeline addresses inflammatory bowel disorders nor does the drugmaker have any cell therapies. The company is checking off both boxes by striking up an alliance with Sonoma Biotherapeutics, a startup working in a hot area of immunology and inflammation drug research.

Sonoma develops therapies based on regulatory T cells, or Tregs. These cells suppress immune responses, and the biotech is developing therapies that leverage that capability as a way of treating autoimmune diseases. According to deal terms announced Tuesday, Regeneron is paying South San Francisco-based Sonoma $75 million up front, which includes a $30 million equity investment in the startup. The first two disease targets for the new partners are ulcerative colitis and Crohn’s disease.

Tregs are like the police officers of the immune system, says Sonoma co-founder and CEO Jeff Bluestone. In autoimmune diseases, effector T cells mistakenly attack healthy tissue. Tregs shut down these rogue responses and restore the immune system to a healthy balance.

Sonoma’s therapies are autologous, meaning they come from the patient. After those cells are harvested, they’re engineered in a lab to go after the right target. The engineered cells are multiplied, then infused back into the patient. Autologous cell therapies have already been validated in cancer. CAR T-therapies are made by harvesting and engineering a patient’s T cells.

Regeneron has capabilities that can contribute to the development of Treg cell therapies. The company’s VelociSuite platform uses mice to discover and develop human antibodies and T cell receptors that address disease targets of interest. The tech platform was used to develop antibodies for its cancer immunotherapy research. Bluestone said the Regeneron technology can be used to rapidly identify receptors and antibodies, enabling the partners to then engineer the receptors that guide the engineered Treg to its target and activate it gets there.

“In our business, the most important thing is the target,” Bluestone said. “It’s got to be right target. It’s got to very specific to the disease.”

The field of Treg research is building momentum. Sangamo Therapeutics has reached Phase 1 testing with a Treg for kidney transplants. Organ transplant patients must receive anti-rejection therapies that circulate systemically. Sangamo’s Treg is engineered with a chimeric antigen receptor that targets an antigen specific to the kidneys, Sangamo Chief Scientific Officer Jason Fontenot told MedCity News in an interview during the J.P. Morgan Health Care Conference in January.

“The innovation here and why we’re so excited is you can target the immune response only to a specific tissue,” he said.

The potential of Tregs has sparked research and investment interest. London-based Quell Therapeutics raised $156 million in 2021 to continue development of a Treg therapy for liver transplant patients. The lead indication for Third Rock Ventures-backed Abata Therapeutics is multiple sclerosis.

Sonoma’s internal research has produced three programs so far, the most advanced of which is a combination drug. While the Treg component of this drug dampens inflammation, the fusion protein part of the therapy depletes and inactivates the effector T cells that are driving the autoimmune response. A Phase 1 test began late last year. A Sonoma Treg therapy for rheumatoid arthritis is approaching the clinic. Bluestone said the startup’s progress sparked partnership discussions in the past year, some of them with big players looking to enter the Treg space.

Along the way, Bluestone said he had conversations with George Yancopoulos, the co-founder, president, and chief scientific officer of Regeneron. The two concluded that their respective companies could bring a synergistic approach to immune regulation. Bluestone said IBD makes sense for a drug research partnership. The applicability of Tregs in these disorders has been validated in preclinical studies, but the large size of the disease area makes it one Sonoma would likely be unable to pursue without a larger partner, Bluestone said.

The agreement calls for both companies to share equally in the R&D costs of the Treg therapies. In addition to ulcerative colitis and Crohn’s disease, the deal covers two additional indications that remain undisclosed. Regeneron also has an option to pursue a fifth indications. Sonoma retains the rights to its internally developed programs.

If the partnership yields any approved products, both companies will share equally in profits from sales. Regeneron has the option to lead late-stage development and commercialization of all potential products stemming from the pact, but Sonoma keeps rights to co-promote these products in the U.S.

As the research progresses, Sonoma is eligible to receive a $45 million milestone payment. Bluestone said the Regeneron deal was not simply about money. The company closed a $265 million Series B financing in 2021, some of which was used to establish an R&D and manufacturing facility in Seattle. Sonoma still has enough money to last “a couple of years,” Bluestone said.

The Regeneron partnership is not an exclusive one, but Sonoma is not looking for more partners. If the company does strike additional deals, they will likely be technology partnerships that bring automation or other advances that improve cell therapy manufacturing, Bluestone said.

Photo by Sonoma Biotherapeutics