Biohaven’s extracellular protein degradation platform has moved into pivotal development after BHV-1300 produced greater than 80% mean reductions in disease-driving autoantibodies in patients with Graves’ disease.
In an ongoing Phase 1b study, weekly 1,000 mg subcutaneous doses of BHV-1300 reduced pathogenic TSHR-IgG1 autoantibodies by more than 80% by week 12 in patients with Graves’ hyperthyroidism. Among participants who continued to have elevated thyroid hormones despite anti-thyroid drug therapy, free T4 normalized at a median of three weeks and free T3 normalized at a median of five weeks following the first dose.
Biohaven said BHV-1300 was safe and well tolerated through 12 weeks, with most adverse events mild and self-resolving and no serious adverse events reported. The company also reported no clinically significant reductions in several other immunoglobulins, supporting its goal of selectively eliminating pathogenic antibodies while preserving broader immune function.
Based on the Phase 1b results, Biohaven initiated a randomized, double-blind, placebo-controlled Phase 3 study in approximately 300 adults with Graves’ hyperthyroidism. The study will evaluate normalization of T3, T4 and TSH at 26 weeks without an anti-thyroid drug.
The company’s broader extracellular degrader platform is also advancing in IgA nephropathy. BHV-1400 produced greater than 60% mean reductions in pathogenic Gd-IgA1 within 48 hours and approximately 70% during the first month of dosing. Biohaven said the early reductions were deeper than those reported with BAFF/APRIL inhibitors, APRIL inhibitors and CD38 inhibitors at comparable early time points.
Biohaven said nearly 200 individuals have now received its first extracellular protein degraders in clinical studies. The company plans to initiate a pivotal study of BHV-1400 in IgA nephropathy during the second half of 2026 and is advancing additional degrader candidates targeting IgG4-mediated disease, PLA2R autoantibodies, pro-insulin autoantibodies and other pathogenic extracellular proteins.
Biohaven ended Q2 with approximately $270.5 million of cash, cash equivalents, marketable securities and restricted cash. Q2 R&D expenses declined to $100.8 million from $184.4 million a year earlier, primarily because of lower direct program and preclinical spending following a strategic reprioritization.
KEY QUOTES:
“What excites me most about Biohaven today is that we’re no longer talking about scientific promise, we’re watching new therapeutic approaches begin to work in patients. This year we’ve crossed important milestones across our portfolio, including advancing BHV-1300 into pivotal development for Graves’ disease and generating compelling patient data from both our Graves’ disease and IgA nephropathy programs.”
“We believe our MoDE and TRAP platforms are doing something fundamentally different: selectively removing the proteins that drive disease while preserving normal immune function. If these data continue to translate into larger studies, extracellular protein degradation has the potential to reshape how autoimmune diseases are treated.”
Vlad Coric, M.D., Chairman And Chief Executive Officer Of Biohaven
