Argo Biopharmaceuticals released new data from a Phase II study on its preventative therapy, BW-20805, for hereditary angioedema (HAE). The multi-national, open-label trial involved 25 patients and aimed to establish how the drug acts in the body while evaluating its potential to reduce swelling episodes. According to the results presented at the Bradykinin Symposium in Berlin, 300mg of BW-20805 dosed once every 24 weeks reduced the average monthly rate of HAE attacks by 96%. This positive impact was consistent across other tested doses, with a 600mg dose every 24 weeks and a 300mg dose every 12 weeks leading to an 83% and 93% drop in attack rates, respectively.
Patient outcomes improved significantly with the treatment. Depending on the dosage, between 50% and 75% of patients remained attack-free between day 29 and day 169. The drug demonstrated rapid and sustained pharmacodynamic activity over the study period. Researchers noted that treatment-emergent adverse events were generally mild, with most being injection site reactions. No serious adverse events led to discontinuation or withdrawal from treatment.
How the mechanism works
Hereditary angioedema is a genetic disorder that causes unpredictable, recurring episodes of severe swelling. It affects roughly one in every 50,000 people globally, typically impacting the hands, feet, face, genitals, and the intestinal tract. BW-20805 is a silent interfering RNA (siRNA) therapy designed to target the mRNA behind the plasma prekallikrein protein (PKK). By durably disabling PKK’s mRNA, Argo claims the therapy addresses the root cause of the condition.
The HAE market is currently dominated by Takeda’s Takhzyro (lanadelumab), a blockbuster preventative therapy that contributed to the Japanese pharma company’s $62bn takeover of Shire in 2019. While Takhzyro is well established, it requires twice-monthly dosing. Argo’s data suggests BW-20805 could offer a significant advantage through its less frequent schedule, though analysts have previously noted that siRNA platforms may provide meaningful differentiation in this competitive setting. Currently, just under half of the innovator drugs in development for HAE are in Phase III.
It is worth noting that emerging therapies in this space often face a long road to approval. The current best-seller’s dominance is built on years of clinical data and patient familiarity, a hurdle that new entrants must clear to gain significant market share. Even with promising Phase II results, the path to Phase III and eventual regulatory approval involves rigorous testing to confirm long-term safety and consistent efficacy across diverse patient populations.
Sensorion Wins Approval for HearConnex Trial in France represents a parallel advancement in therapeutic trials. This approval highlights the increasing focus on specialized treatments for rare conditions. The rigorous process required to reach such milestones ensures that only therapies with proven potential proceed to later stages of development.
