Despite Biohaven’s bispecific protein degrader cutting autoantibody IgG levels by up to 37% in an early-stage study, investors saw it as “below the high bar” of 60%, according to William Blair analysts.
Biohaven on Wednesday unveiled Phase I data for its protein degrader BHV-1300, touting a rapid, substantial and selective reduction in levels of autoantibody IgG in healthy volunteers. However, investors were not impressed with BHV-1300’s performance as Biohaven’s shares dropped 12.6% in reaction to the readout, according to Investor’s Business Daily.
Within 96 hours of treatment, BHV-1300 elicited a dose-dependent decrease in IgG levels, with preliminary data showing that some patients saw their concentrations drop to as low as 50% to 70% of baseline. In the highest dose cohort, the average reduction was around 37%.
Biohaven also detected no significant impact on albumin, cholesterol and low-density lipoprotein levels, as well as on liver function metrics, vital signs or electrocardiogram outcomes. Most of the side effects were mild or were otherwise deemed unrelated to the study drug. There were no serious or severe adverse events.
Given these early data, CSO Bruce Car in a statement called BHV-1300 “promising” and said the biotech plans to advance it “through upcoming milestones” alongside other candidates. “We are excited about the progress our R&D team is making in pursuing new druggable targets and disrupting older therapies with optimized technology with the goal of changing treatment paradigms.”
William Blair analysts in a Wednesday research note said that Biohaven’s 37% IgG reduction falls “below the high bar for 60% IgG lowering we had heard as a single-dose bogey from many investors.” Nevertheless, the biotech is planning to add two more cohorts to its Phase I single-ascending dose (SAD) study, with modeling data suggesting that these could yield a more than 70% reduction in IgG.
“Overall, we are encouraged by what appears to be a relatively clean safety profile,” William Blair analysts wrote, adding that while the initial SAD data may be disappointing, “we see potential for the product, especially in combination studies” due to its “differentiated mechanism of action.”
BHV-1300 is an investigational bispecific protein degrader that works by seeking out and binding to pathogenic IgG forms and bringing them to the liver for degradation. This mechanism of action gives BHV-1300 therapeutic potential for antibody-driven diseases such as rheumatoid arthritis, myasthenia gravis and systemic lupus erythematosus, according to the biotech’s website.
Biohaven is trying to potentially compete with argenx’s Vyvgart (efgartigimod), which is approved for myasthenia gravis and is being studied for other autoimmune diseases. Vyvgart is currently being reviewed for chronic inflammatory demyelinating polyneuropathy, with a target action date of June 21, 2024. On Wednesday, argenx’s stock rallied 3.1% after Biohaven’s data drop.
Tristan Manalac is an independent science writer based in Metro Manila, Philippines. Reach out to him on LinkedIn or email him at tristan@tristanmanalac.com or tristan.manalac@biospace.com.
