Tolerance Bio Licenses TLB-33 to Expand Thymic Health Pipeline

Tolerance Bio has entered into an exclusive licensing agreement with Tanabe Pharma Corporation to develop and commercialize TLB-33, a clinical-stage anti-IL-33 monoclonal antibody, across multiple indications.

Under the agreement, Tolerance Bio will receive worldwide development and manufacturing rights for TLB-33, formerly known as MT-2990. The company will also hold exclusive commercialization rights outside Japan, while Tanabe Pharma will retain commercialization rights in Japan.

Tolerance Bio is developing therapies aimed at preserving and restoring thymic function, which plays an important role in maintaining immune health. The company plans to advance TLB-33 into Phase 2 clinical development to assess its potential to preserve thymic function and support immune resilience. Other immune-related indications are also being considered.

TLB-33 has already been studied in more than 150 people across several clinical trials. According to Tolerance Bio, these studies have generated human safety and biological activity data that support further development of the antibody in new indications.

The addition of TLB-33 expands Tolerance Bio’s clinical pipeline across several therapeutic approaches, including biologics, mRNA and cell therapies. The company recently licensed efineptakin alfa, a long-acting interleukin-7 (IL-7) therapy from NeoImmuneTech, adding another potential approach to preserving and restoring thymic function.

Tolerance Bio CEO Francisco Leon said the company believes blocking IL-33 could help preserve thymic function, particularly in inflammatory conditions where IL-33 signaling may contribute to thymic decline. He also said TLB-33 and efineptakin alfa could provide complementary approaches to supporting immune resilience.

The company said it plans to use an expected financing round to support the development of TLB-33 and efineptakin alfa through planned clinical trials.

Under the licensing agreement, Tanabe Pharma is eligible to receive potential development and sales milestone payments of up to approximately $560 million, along with equity consideration and tiered royalties based on net sales.

With TLB-33 now added to its pipeline, Tolerance Bio aims to build a broader therapeutic platform focused on thymic biology and immune function.