Written by Marc Chatenay-Lapointe, Ph.D. and Jason Jardine

On July 13, 2017, the U.S. Food and Drug Administration approved Tremfya (guselkumab), a biologic manufactured by Janssen Biotech, for the treatment of moderate-to-severe plaque psoriasis patients who are candidates for systemic therapy or phototherapy.

Plaque psoriasis is a chronic autoimmune disease characterized by elevated patches of inflamed and itchy skin called plaques. Interleukin-23 (IL-23) is a cytokine that promotes inflammation and immune responses, and its dysregulation is implicated in the pathogenesis of various autoimmune diseases, including plaque psoriasis. According to Tremfya’s Prescribing Information, this biologic is “a human monoclonal IgG1λ antibody that selectively binds to the p19 subunit of IL-23 and inhibits its interaction with the IL-23 receptor” and “inhibits the release of proinflammatory cytokines and chemokines.” It was noted in a National Psoriasis Foundation press release that “not all patients respond similarly to currently available treatments,” and that “[f]or the more than one million Americans living with moderate to severe plaque psoriasis, the approval of Tremfya offers physicians and patients an effective new therapy.” (Quoting Michael Siegel, Ph.D., Vice President of Research Programs for the National Psoriasis Foundation).

The FDA approval of Tremfya was based on data derived from three Phase 3 studies: VOYAGE 1, VOYAGE 2 and NAVIGATE. According to a Janssen press release, “at 16 weeks, at least seven out of ten TREMFYA™-treated patients achieved at least 90 percent clearer skin, and more than 80 percent demonstrated cleared or almost cleared skin.” Janssen further noted that, “more than seven out of ten patients treated with TREMFYA™ reported at least 90 percent clearer skin compared with more than four out of ten patients treated with Humira®.”

The FDA’s regulatory review of Tremfya was expedited due to Janssen’s use of a priority review voucher that it had been awarded in 2012 for approval of Sirturo, a treatment for multi-drug-resistant tuberculosis. Under a system created to incentivize drug development for particular diseases prevalent in poor countries, FDA guidance explains that sponsors of approved tropical disease product applications are “eligible for a voucher that can be used to obtain a priority review for a subsequent human drug application.” The FDA further notes that the human drug application for which the voucher can be used is not limited to tropical disease therapeutics, and that the voucher is also transferable (including by sale) to another of a human drug application sponsor. This voucher program has since been extended to sponsors of rare pediatric disease product applications. Thus far, fourteen priority review vouchers have been granted by the FDA: ten for rare pediatric disease drugs and four for tropical disease therapeutics. On the secondary market the vouchers have purchased for prices as high as $350 million by drug manufacturers seeking to obtain earlier market entry of their blockbusters via priority review of their FDA applications.