Incyte's Phase 3 Results for Povorcitinib in Hidradenitis Suppurativa Fall Short of Expectations

Incyte Corporation has announced the results of two pivotal Phase 3 trials for its oral JAK1 inhibitor, povorcitinib, in the treatment of hidradenitis suppurativa (HS). While the trials met their primary endpoints, the efficacy data fell short of expectations, leading to a significant drop in the company's stock price.

Trial Results and Market Reaction

The two Phase 3 studies evaluated povorcitinib's efficacy in reducing total abscess and inflammatory nodule count in patients with HS. In the first study, approximately 40% of patients on both low and high doses achieved the primary endpoint, compared to 30% on placebo. The second study showed similar results, with 42% of treated patients meeting the criteria versus 29% on placebo.

However, the placebo-adjusted response rates of 10.5% and 10.9% for low and high doses in the first trial, and 13.7% for both doses in the second trial, were notably lower than the 17.3% and 27.7% observed in the earlier Phase 2 study. This discrepancy led to a sharp 15% decline in Incyte's share price, with the stock trading at around $58 in early premarket trading.

Comparative Landscape and Market Implications

The underwhelming results have raised concerns about povorcitinib's potential market position, especially when compared to existing biologic treatments. UCB's Bimzelx, recently approved for HS, demonstrated placebo-adjusted response rates of 19% and 20% in its Phase 3 trials. Novartis's Cosentyx is another approved biologic for this indication.

While povorcitinib offers the advantage of oral administration, the lower efficacy rates may limit its market opportunity. Incyte had positioned the drug as a potential oral alternative to biologics in multiple indications and as a partial offset to the anticipated loss of exclusivity for its JAK inhibitor, Jakafi, later this decade.

Additional Findings and Safety Profile

Despite the disappointing primary outcome, Incyte reported some positive secondary findings. The drug showed higher placebo-adjusted results in a predefined subgroup of patients who had previously taken biologics. Additionally, more patients on povorcitinib experienced a 75% or greater improvement, reduction in flares, and significant pain relief compared to placebo.

The company stated that the overall safety profile of povorcitinib was consistent with previous data, although specific details were not provided in the initial announcement.

As the pharmaceutical industry continues to seek effective treatments for hidradenitis suppurativa, Incyte's mixed results highlight the challenges in developing therapies for this complex inflammatory skin condition. The company will likely need to conduct further analysis and possibly additional studies to determine povorcitinib's future in the HS treatment landscape.