Phase 3 data for Pfizer’s oral drug Litfulo, known generically as ritlecitinib, could pave the way for regulatory submissions to treat nonsegmental vitiligo, a condition affecting about 70 million people worldwide. The company presented detailed trial results Friday at the European Academy of Dermatology and Venereology annual meeting in Vienna, Austria. Based on these findings, Pfizer plans to submit the data to health authorities for approval in this indication.
How the Immune System Attacks Melanin
Vitiligo occurs when the immune system targets cells that produce melanin, the pigment responsible for skin color. This autoimmune reaction leads to visible patches of skin discoloration. While the disorder can appear anywhere on the body, the changes are most noticeable on the face, neck, and hands. The disease manifests in two main forms: segmental vitiligo, which affects only one side of the body, and nonsegmental vitiligo, or generalized vitiligo, which develops on both sides.
The Global Vitiligo Foundation estimates that 1% to 1.5% of the global population lives with this chronic condition. Currently, patients have limited treatment options available to them. Pfizer’s Litfulo is an oral small molecule designed to block the JAK3 and TEC proteins, which are involved in the immune response driving autoimmune disease. The FDA first approved Litfulo in 2023 for the treatment of alopecia areata.
Trial Results Show Significant Improvement
Pfizer advanced Litfulo in two global Phase 3 studies, enrolling a total of 2,174 patients. The trials assessed both a high dose and a low dose of the drug. In the U.S., the primary goals were measuring the percentage of patients who achieved 75% or greater improvement in facial re-pigmentation and 50% improvement across the entire body. Both measures were assessed at week 52. Outside the U.S., the 75% facial measure was the primary endpoint.
The data presented Friday showed that 21.8% of patients receiving the high dose met the facial measure, compared to 12.4% in the low dose group. Placebo recipients achieved this goal at a rate of about 2.4%. On the measure of total body pigment improvement, 13% in the high dose cohort reached the trial goal, versus 8.9% in the low dose group and 1.9% of those on placebo. Improvement began at week 24 and continued through week 52 in both studies.
Related Treatments and Industry Revenue
Other JAK inhibitors carry a black box warning for cancer and heart issues. Opzelura is a topical cream for vitiligo. Pfizer’s Litfulo is an oral pill. Incyte reported $678.5 million in Opzelura revenue for 2025. This figure is a 33.4% increase from the prior year.
Market Competition and Safety Profile
Dr. Iltefat Hamzavi, a senior staff physician at Henry Ford Health and Hamzavi Dermatology Specialists, commented on the results. “Research has shown that Litfulo not only significantly improved facial and total body repigmentation, but also resulted in greater disease stabilization compared to the placebo,” Hamzavi said in a prepared statement. “The results solidify the potential of Litfulo to support a new treatment paradigm rooted in systemic treatment that can address underlying disease drivers for people living with nonsegmental vitiligo.”
Regulatory Pathways and Future Rivals
Pfizer plans to submit the Phase 3 results for review by both the FDA and the European Medicines Agency. If approved, Litfulo would face an increasingly competitive market. In July, AbbVie added nonsegmental vitiligo to the label of its JAK inhibitor Rinvoq in Europe. The pill is currently under FDA review for this indication.
More competition is on the horizon. Teva Pharmaceutical is developing an antibody designed to inhibit the signaling protein IL-15 to treat autoimmune disease. Following encouraging Phase 1b results reported in July, Teva said it plans to advance this drug to Phase 2b testing in vitiligo. Meanwhile, Argenx aims to address the skin disorder with a drug from its recent Forte Biosciences acquisition. Forte’s antibody blocks IL-2 and IL-15 signaling to activate immune cells, and the company was developing this treatment for both vitiligo and celiac disease.
