In hopes of challenging Incyte’s topical JAK inhibitor Opzelura, Pfizer is headed to regulators with results from a pair of late-stage studies testing its would-be oral rival Litfulo in nonsegmental vitiligo (NSV).
Pfizer assessed Litfulo—also known as ritlecitinib and first cleared by the FDA to treat severe alopecia areata in in mid-2023—in a pair of phase 3 trials dubbed Tranquillo and Tranquillo 2, focusing on patients ages 12 and older and just adults, respectively. The company said Thursday that it enlisted participants with both active and stable NSV across a broad spectrum of disease severity.
NSV is a chronic autoimmune disease that causes the immune system to attack cells that make melanin, in turn causing loss of pigment that leads to white macules and patches forming on the skin and hair over time. Pfizer noted that although vitiligo is frequently thought of as a cosmetic condition, it is nevertheless “a serious autoimmune disease that can have considerable impact on patients’ lives well beyond the physical symptoms.”
As it stands, Incyte’s Opzelura—applied to the body as a cream—is the only drug approved by the FDA to treat NSV. Pfizer is arguing that patients with NSV could benefit from a new systemic therapy to tackle their autoimmune condition.
Moreover, there are some patients “for whom disease burden warrants more than localized treatment alone,” Iltefat Hamzavi, M.D., a senior staff physician in the dermatology department at Henry Ford Health and Hamzavi Dermatology Specialists, said in Pfizer’s release.
According to topline results from the Tranquillo trials, both a 50 mg and 100 mg dose of Litfulo charted statistically significant improvements over placebo on co-primary endpoints tied to the facial and total body Vitiligo Area Scoring Index (VASI), a clinician-reported tool to assess vitiligo severity and treatment response.
Pfizer noted that in both trials, “significantly more patients” who received Litfulo achieved a 75% or greater improvement on the facial scoring index (F-VASI75) and a 50% or greater improvement on the total vitiligo scoring index (T-VASI50) at the one-year mark versus placebo.
The company noted that its co-primary endpoints in the U.S. are the proportion of patients with F-VASI75 and the proportion of patients with T-VASI50 at 52 weeks, while in countries outside the U.S., F-VASI75 is the sole primary endpoint.
Litfulo’s safety and tolerability were on par with its reputation in alopecia areata, Pfizer said, adding that the proportion of patients with treatment-emergent adverse events was similar across cohorts.
Litfulo in its approved form carries warnings about its potential to lower the immune system’s ability to fight infections, cause cancers, and lead to potential heart issues and blood clots, none of which are uncommon for the JAK inhibitor class at large.
With positive results in hand, Pfizer said it now plans to submit regulatory filings around the world in vitiligo, with the aim to target an approval in adults. The New York pharma also intends to share additional data from the two studies at an upcoming medical meeting.
As for Opzelura, the topical drug received a tailwind recently following a settlement with the Centers for Medicare & Medicaid Services on how the drug was classified in determining its rebate. With that issue resolved, Incyte earlier this week raised its full-year 2026 sales guidance for Opzelura from below $800 million to a blockbuster range of $1.05 billion to $1.1 billion.
Meanwhile, another challenger could be close at hand in AbbVie’s JAK med Rinvoq, which on Wednesday picked up dual approvals in the European Union to treat both alopecia areata and NSV. Stateside, AbbVie submitted Rinvoq for FDA review in vitiligo back in early February.