Biohaven's Lead Protein Degrader Phase I Data Disappoints Investors

Biohaven revealed promising Phase I results for its experimental protein degrader, BHV-1300, highlighting a rapid and significant reduction in autoantibody IgG levels among healthy participants. Despite these findings, the company’s shares decreased by 12.6%, reflecting investor disappointment.

The Phase I study showcased that within 96 hours of administering BHV-1300, participants experienced a dose-dependent decrease in IgG levels. Preliminary data indicated that some individuals’ IgG concentrations dropped to between 50% and 70% of their baseline levels, with the highest dose group showing an average reduction of approximately 37%.

Importantly, Biohaven reported no significant changes in albumin, cholesterol, or low-density lipoprotein levels. Additionally, liver function tests, vital signs, and electrocardiogram results remained stable. Most side effects were mild or not related to the study drug, and no severe adverse events were observed.

In light of these initial results, Biohaven’s Chief Scientific Officer Bruce Car described BHV-1300 as “promising.” He emphasized the company’s commitment to advancing this candidate through future developmental milestones alongside other investigational drugs. Car expressed enthusiasm about the ongoing efforts to target new therapeutic areas and improve upon existing treatments with innovative technology.

However, some analysts, particularly from William Blair, noted that the 37% reduction in IgG fell short of the 60% reduction that many investors had hoped for from a single dose. Despite this, Biohaven plans to add two more cohorts to its ongoing Phase I single-ascending dose (SAD) study, with predictive models suggesting these additions could achieve over a 70% reduction in IgG levels.

William Blair analysts found the safety profile of BHV-1300 encouraging, noting that while the initial data might be underwhelming, the drug's unique mechanism could make it valuable in combination therapies. BHV-1300 is designed as a bispecific protein degrader that targets pathogenic IgG antibodies for degradation in the liver. This mechanism could be particularly beneficial for treating antibody-mediated diseases such as rheumatoid arthritis, myasthenia gravis, and systemic lupus erythematosus, as per Biohaven’s information.

The biotech firm is eyeing competition with argenx’s Vyvgart (efgartigimod), a drug approved for myasthenia gravis and under investigation for other autoimmune conditions. Vyvgart is currently being reviewed for its efficacy in treating chronic inflammatory demyelinating polyneuropathy, with a decision expected by June 2024. Following Biohaven’s data release, argenx saw a 3.1% increase in its stock price.

Overall, although the initial data from the BHV-1300 study may not have met investor expectations, the drug’s safety profile and its potential in combination treatments highlight its promise. Biohaven remains committed to further exploring BHV-1300’s potential in future clinical trials, aiming to offer new therapeutic options for patients with antibody-driven diseases.