Tolerance Bio Licenses Efineptakin Alfa From NeoImmuneTech to Advance Thymus-Targeted Therapies
Tolerance Bio, Inc., a biotechnology company focused on preserving, regenerating, and modulating thymic function to address immune-related diseases and potentially extend healthspan, has entered into an exclusive license agreement with NeoImmuneTech for the development and commercialization of efineptakin alfa, also known as NT-I7. The clinical-stage long-acting interleukin-7 (IL-7) fusion protein will be developed for selected thymus-related indications in the Americas and Europe.
The agreement represents a significant milestone for Tolerance Bio, marking the company’s transition into a clinical-stage biotechnology organization. With efineptakin alfa now added to its development portfolio, Tolerance Bio plans to advance the program toward Phase 2 clinical testing focused on enhancing thymic function and improving immune resilience in populations affected by immune dysfunction.
The company currently expects HIV immunological non-response to be among the initial indications evaluated in Phase 2. This condition represents a potential model of accelerated immune aging in which some individuals living with HIV experience inadequate immune recovery despite effective control of the virus with antiretroviral therapy.
Tolerance Bio believes that studying thymic function in this population could provide important clinical insights into the potential of IL-7-based therapies to restore or strengthen immune capacity.
Focus on Thymic Function and Immune Resilience
The thymus plays a central role in the development and maturation of T cells, which are essential components of the adaptive immune system. However, thymic activity declines with age and can also be impaired by disease, infection, certain treatments, and other physiological stresses.
Reduced thymic function can contribute to diminished immune resilience, potentially leaving individuals less capable of responding effectively to new infections, vaccines, or other immune challenges.
Tolerance Bio is developing therapies designed to address this underlying biology directly. Rather than focusing exclusively on individual diseases or symptoms, the company’s approach centers on preserving, regenerating, and modulating the thymus to improve immune function.
The addition of efineptakin alfa strengthens this strategy by providing the company with a clinical-stage biologic that has already been evaluated in human studies.
Efineptakin alfa is a long-acting IL-7 fusion protein designed to enhance immune cell activity. IL-7 is a naturally occurring cytokine involved in the development, maintenance, and homeostasis of T cells.
The therapeutic potential of IL-7 has been investigated in multiple clinical settings, including situations in which immune recovery or T-cell restoration may be beneficial.
According to Tolerance Bio, the IL-7 therapeutic class has demonstrated evidence of thymic and T-cell stimulation along with a favorable safety history.
Efineptakin Alfa Has Extensive Clinical Experience
One of the key advantages of the licensing agreement is the existing clinical experience associated with efineptakin alfa.
The therapy has been evaluated in more than 800 subjects across multiple clinical studies. These studies have generated human safety, tolerability, pharmacologic, and proof-of-principle information that Tolerance Bio believes can support continued development.
Having an investigational therapy with substantial prior clinical experience could potentially allow Tolerance Bio to move more efficiently toward its planned Phase 2 program.
Instead of beginning development with a newly discovered molecule that has limited human exposure data, the company can build on an existing body of clinical knowledge while focusing its efforts on specific thymus-related indications.
The planned Phase 2 studies will be important for determining whether the biological effects observed with efineptakin alfa can translate into meaningful improvements in thymic function and immune resilience in targeted patient populations.
HIV Immunological Non-Response as an Initial Focus
Tolerance Bio currently expects HIV immunological non-response to be among the first indications investigated in its Phase 2 development program.
For people living with HIV, effective antiretroviral therapy can suppress viral replication and dramatically improve long-term health outcomes. However, not every patient experiences the same degree of immune recovery.
Some individuals continue to have inadequate restoration of CD4 T-cell counts despite sustained viral suppression. This phenomenon, often referred to as immunological non-response, represents an important area of unmet medical need.
The condition also provides a potentially useful clinical setting for investigating approaches aimed at improving immune regeneration.
Because thymic activity and T-cell production are closely connected, Tolerance Bio believes that stimulating thymic function could offer a complementary approach to conventional antiviral treatment.
The company plans to evaluate whether efineptakin alfa can enhance thymic activity and contribute to improved immune recovery in this population.
Expanding a Thymus-Focused Pipeline
The licensing agreement also expands Tolerance Bio’s broader therapeutic pipeline.
The company is developing multiple approaches directed toward thymus biology, including biologic therapies, thymus-targeting messenger RNA technologies, and thymus cell therapies.
These modalities are intended to address different aspects of thymic biology while pursuing the overarching goal of preserving, regenerating, and modulating thymic function.
The addition of efineptakin alfa gives the company an established biologic platform alongside its emerging technologies.
Tolerance Bio believes the combination of these approaches could enable it to build a comprehensive therapeutic platform focused specifically on thymic biology and immune resilience.
The company’s strategy is based on the idea that improving thymic function could have applications across a range of diseases and populations characterized by immune vulnerability.
Potential future applications may extend beyond the initial Phase 2 indications as the company develops a deeper understanding of how thymus-targeted therapies affect immune function.
Transition to Clinical-Stage Development
For Tolerance Bio, the transaction represents more than the addition of another program. It marks the company’s transition into the clinical development stage.
Moving from preclinical research into human trials is a major milestone for biotechnology companies because it provides an opportunity to directly evaluate the safety, pharmacology, and therapeutic potential of a technology in patients.
Tolerance Bio intends to use the existing clinical experience with efineptakin alfa as a foundation for its next development phase.
Francisco Leon, MD, PhD, chief executive officer of Tolerance Bio, described the agreement as an important step in the company’s efforts to advance its thymus-focused pipeline.
Leon emphasized that efineptakin alfa is a well-characterized clinical-stage cytokine with the potential to promote thymic and T-cell activity.
He also highlighted the potential role of long-acting IL-7 in preserving and regenerating thymic function in immunologically vulnerable populations.
According to Leon, research in these populations could serve as an important stepping-stone toward investigating whether IL-7-based therapies might eventually contribute to maintaining immune health more broadly as people age.
Partnership With NeoImmuneTech
The license agreement brings together Tolerance Bio’s expertise in thymus biology and NeoImmuneTech’s experience with efineptakin alfa.
NeoImmuneTech has been developing NT-I7 as a long-acting IL-7-based therapeutic candidate and has generated clinical data across multiple disease areas.
Taekyung Kim, chief executive officer of NeoImmuneTech, said the company was pleased to partner with Tolerance Bio to advance NT-I7 in the area of thymic insufficiency.
Kim highlighted Tolerance Bio’s focus on thymus biology and its commitment to addressing immune diseases as important reasons for the collaboration.
Under the agreement, Tolerance Bio will receive exclusive rights to develop and commercialize efineptakin alfa for certain thymus-related indications in the Americas and Europe.
NeoImmuneTech will continue to support the program as the therapy moves forward under Tolerance Bio’s development strategy.
Financial Terms of the Agreement
The agreement includes potential development and sales milestone payments of up to $260 million.
In addition to these potential milestone payments, the transaction includes equity consideration and tiered royalties based on net sales.
The financial structure aligns the interests of the companies around the continued development and potential commercialization of efineptakin alfa.
For Tolerance Bio, the transaction provides access to a clinical-stage therapeutic candidate without requiring the company to discover and develop a new molecule from the earliest stages of research.
For NeoImmuneTech, the agreement provides an opportunity to advance the potential of NT-I7 in thymus-related indications through a partner specifically focused on thymic biology.
Potential Role in Immune Aging
The company’s broader vision extends beyond treating specific immune diseases.
Tolerance Bio believes that declining thymic function may be an important component of biological aging and reduced immune resilience.
As the thymus naturally becomes less active with age, the production of new T cells can decline. This may affect the ability of the immune system to respond to emerging threats and maintain a diverse repertoire of immune cells.
By developing therapies that preserve or restore thymic function, Tolerance Bio is exploring whether it may be possible to improve immune resilience over a longer period.
Efineptakin alfa could become an important component of this strategy if future clinical studies demonstrate that its effects on thymic biology translate into meaningful improvements in immune function.
The company is therefore positioning the current development program as an opportunity to generate clinical evidence in immunologically vulnerable populations while potentially establishing a foundation for broader healthspan applications.
Advancing a New Therapeutic Strategy
The focus on thymic biology represents a relatively differentiated approach within the biotechnology industry.
Many immune-related therapies target individual immune cells, inflammatory pathways, or disease-specific mechanisms. Tolerance Bio is instead seeking to address the organ responsible for a critical stage of T-cell development.
The company believes that strengthening thymic function could have broader effects on immune system health.
Its pipeline of biologics, mRNA-based approaches, and cell therapies reflects an effort to develop multiple technologies around this central biological target.
The acquisition of exclusive development and commercialization rights to efineptakin alfa provides an opportunity to test this strategy in human clinical trials using a therapeutic candidate with significant previous clinical exposure.
Following the completion of the licensing agreement, Tolerance Bio plans to prepare for Phase 2 clinical development of efineptakin alfa in thymus-related indications.
HIV immunological non-response is expected to be among the initial areas of investigation, providing a clinically relevant population in which immune recovery remains an important challenge.
Future studies will help determine whether efineptakin alfa can enhance thymic function, increase T-cell production, and ultimately improve immune resilience.
The results will also help guide the potential expansion of the program into other populations affected by thymic dysfunction or immune aging.
For Tolerance Bio, the agreement with NeoImmuneTech represents a major step toward establishing a clinical platform focused on thymic biology. With efineptakin alfa joining its pipeline alongside thymus-targeting mRNA and cell therapy programs, the company is seeking to develop a comprehensive portfolio aimed at preserving and restoring immune function.
As the global population ages and immune resilience becomes an increasingly important area of research, therapies capable of supporting thymic function could have broad potential. The upcoming clinical studies will be critical in determining whether this biological strategy can translate into meaningful benefits for patients and, ultimately, support the company’s longer-term ambition of using thymus-focused therapies to address immune disease and potentially extend healthy lifespan.
About efineptakin alfa and the thymus
Efineptakin alfa (NT-I7) is a clinical-stage long-acting interleukin-7 (IL-7), a next-generation fusion protein with two IL-7 moieties stabilized by N-terminal engineering and genetically fused to the hyFc long-acting platform, designed to extend half-life and support sustained IL-7 activity.
Efineptakin alfa has been evaluated in over 800 subjects across fifteen clinical studies, generating safety, tolerability, pharmacologic and clinical data that support further clinical development.
The thymus plays a central role in T-cell maturation and immune competence but progressively involutes with age and in the context of acute and chronic inflammatory triggers such as infection. This decline contributes to increased susceptibility to additional infections, cancer, autoimmunity and reduced vaccine responsiveness.
IL-7 stimulates thymic function as well as T cell differentiation, proliferation and survival. Its deficiency leads to T cell decline, while its pharmacological administration has been found to increase thymic and T cell function in humans, including people with cancer and people living with HIV who are immunological non-responders, a model of accelerated immune aging and an unmet medical need.
Tolerance Bio plans to advance efineptakin alfa in new indications aligned with its strategy to preserve thymic T cell output and enhance immune resilience in immunologically vulnerable populations.
About Tolerance Bio
Tolerance Bio is a biotechnology company focused on preserving, regenerating and modulating thymic function to address immune diseases and extend healthspan. The Company is developing a pipeline of therapies targeting thymus biology, including biologics, thymus-targeted mRNA and thymus cell therapies. Tolerance Bio is backed by leading life-sciences investors, including Columbus Venture Partners, Criteria Bio Ventures, Pacific 8 Ventures, and BioAdvance Capital. Learn more at www.tolerancebio.com
About NeoImmuneTech
NeoImmuneTech, Inc. (NIT) is a global biotechnology company focused on T-cell-based immunotherapies. NIT is developing NT-I7 (efineptakin alfa), a long-acting human interleukin-7 designed to enhance and restore T-cell function, for oncology, infectious diseases, and other immune-related indications. NeoImmuneTech is advancing NT-I7 both as a monotherapy and in combination with various immunotherapeutic approaches, including CAR-T cell therapies. Learn more at www.neoimmunetech.com