Tolerance Bio, the Philadelphia-based biopharmaceutical company built around restoring thymus function, has licensed efineptakin alfa (NT-I7), a clinical-stage long-acting interleukin-7 therapy, from Rockville, Maryland-based NeoImmuneTech. The exclusive deal covers thymus-related indications across the Americas and Europe and gives Tolerance Bio a clinical-stage asset it plans to move into Phase 2 trials, a significant acceleration for a company that only launched with seed funding in October 2024. CEO Dr. Francisco Leon called the agreement a turning point for the company’s pipeline: “This agreement represents an important milestone for Tolerance Bio as it allows us to rapidly advance into the clinic and continue to build our thymus-focused pipeline.”
What Tolerance Bio Is Actually Getting
Efineptakin alfa is a long-acting IL-7 fusion protein, engineered with two stabilized IL-7 moieties fused to a hyFc platform designed to extend the drug’s half-life and sustain its activity in the body. It’s not an unproven compound: NeoImmuneTech has evaluated it in more than 800 subjects across multiple clinical studies, including people living with HIV and cancer patients, giving Tolerance Bio a running start with real human safety data rather than a preclinical program. Leon framed the appeal of the drug class in those terms: “Efineptakin alfa is a well-characterized clinical-stage thymus-promoting cytokine. The IL-7 therapeutic class has a proven track record of thymus and T cell boosting as well as a favorable safety track record.”
Where Tolerance Bio Plans to Take It First
The company intends to begin Phase 2 trials evaluating efineptakin alfa specifically for thymic function enhancement, with HIV immunological non-response, a condition where patients on antiretroviral therapy still fail to rebuild healthy T cell counts, among the initial target indications. Leon described the broader ambition behind that starting point: “We believe that long-acting IL-7 offers an opportunity to preserve and regenerate thymic function and improve immune resilience in immunologically vulnerable populations, a stepping-stone into the study of IL-7 to promote healthspan in broader populations.” NeoImmuneTech CEO Taekyung Kim framed the partnership as a natural fit for the compound’s next phase: “We are pleased to partner with Tolerance Bio to advance NT-I7 for thymic insufficiency. Tolerance Bio’s expertise in thymus biology and commitment to addressing immune diseases make it a strong partner for this program.”
The Deal Terms and a Fast-Moving Company
The agreement includes development and sales milestone payments worth up to $260 million, along with equity consideration and tiered royalties on future net sales, structured as a licensing deal rather than an acquisition. It marks a rapid climb for Tolerance Bio, which launched in October 2024 with $17.2 million in seed financing, closed a $20.2 million seed round in December 2024, and has now moved from preclinical thymic organoid research into licensing a clinical-stage asset in under two years. The deal also lands amid growing competitive interest in thymus-targeting biology more broadly; FierceBiotech’s coverage of the transaction noted United Therapeutics’ $140 million acquisition of a thymic cell therapy startup this past July as part of that same wave.
Two Regions the Company Calls Home
This deal quietly connects two of the life sciences hubs this publication covers most closely. Tolerance Bio is headquartered in Philadelphia, while NeoImmuneTech, the company on the other side of the licensing table, is based in Rockville, Maryland, squarely within the BioHealth Capital Region. It’s a reminder that partnerships like this one don’t always travel far to find the right counterpart: two mid-Atlantic biotech hubs, roughly two hours apart by car, are now tied together through a single thymus-focused drug program.
