Lassen Therapeutics Closes Oversubscribed $85 Million Series B Financing

Lassen Therapeutics, a clinical-stage biotech company developing first-in-class antibody therapeutics, announced today the successful closing of an oversubscribed Series B financing, raising $85 million. The financing was co-led by Frazier Life Sciences and new investor Longitude Capital, with participation from new investors BVF Partners and Catalio Capital Management, as well as existing investors Alta Partners and Longwood Capital. Concurrent with this financing, Brian Liu, M.D., from Longitude Capital, and Matthew Hobson, Ph.D., from Catalio Capital Management, have joined the Board of Directors.

The proceeds from this financing will support the LASN01 clinical program and advance IND-enabling activities for LASN500. LASN01 targets the interleukin-11 receptor (IL-11R) as a potential treatment for fibro-inflammatory diseases such as TED and IPF, while LASN500 is a highly potent, first-in-class monoclonal antibody targeting the interleukin-18 binding protein (IL-18BP) as a potential treatment for cancer.

The clinical program for LASN01 is primarily focused on TED, with a cohort in IPF in the Phase 1 program. Lassen recently presented data using orbital fibroblast cells from TED patients, demonstrating that LASN01 suppresses multiple markers associated with TED disease progression, including hyaluronan production, cell proliferation, and other markers such as procollagen.

Maria Fardis, Ph.D., Chief Executive Officer of Lassen, expressed her satisfaction with the recent advancements, stating, “I am very pleased with the recent advancements at Lassen, particularly in successfully concluding the Series B financing round, which will facilitate the continued development of our two pipeline products. The proceeds allow us to advance LASN01 Phase 1 and 2 clinical programs and develop a subcutaneous formulation for LASN01. This antibody has significant potential as a treatment for fibro-inflammatory disorders including TED. Our data in orbital fibroblasts have been highly encouraging and paired with our Phase 1 single and multiple ascending dose safety data, support advancement of LASN01 in Phase 2 for TED.”

Brian Liu, M.D., Managing Director at Longitude Capital, expressed excitement about Lassen and the opportunity to develop two first-in-class programs. He stated, “We are very excited about Lassen and the opportunity to develop two first-in-class programs, one in fibro-inflammatory disorders and the other in cancer, along with the management team’s ability to expeditiously execute these programs in pursuit of new therapeutic options for patients. We are encouraged by the progress of LASN01, the lead program at Lassen, which is entering Phase 2 and is a first-in-class antibody that binds to a novel target, an important differentiator in a broad set of fibro-inflammatory indications addressing serious unmet medical needs.”