Ventyx Biosciences is terminating most work on its lead drug candidate for inflammatory diseases despite achieving the main goal of a mid-stage study in plaque psoriasis. The results fall short of those posted by one approved medicine and others still in development in an increasingly competitive field. Ventyx said late Monday that it will no longer continue developing the molecule for plaque psoriasis and psoriatic arthritis.
The Ventyx drug, VTX958, is a small molecule designed to selectively block TYK2, an enzyme that mediates signaling pathways involved in inflammation. It’s the same target hit by Bristol Myers Squibb’s Sotyktu, which last year became the first FDA-approved TYK2 inhibitor for plaque psoriasis, a chronic autoimmune condition affecting the skin.
Ventyx’s placebo-controlled Phase 2 test evaluated four doses of VTX958 in patients with plaque psoriasis. The main goal was to measure the proportion of study participants achieving 75% reduction at week 16 according to the Psoriasis Area and Severity Index (PASI 75), a rating scale used to assess the severity of symptoms.
According to an investor presentation from San Diego-based Ventyx, 49% of patients in the two highest dose groups achieved the main study goal. Nevertheless, those results were short of an internal goal to justify advancing the molecule to Phase 3 testing. Ventyx did not specify that goal, but the company was likely looking to be in the neighborhood of BMS’s Sotyktu. In that drug’s pivotal trial, 58% of patients achieved PASI 75 at week 16; 69% met that mark at week 24.
Other companies are vying to compete on the TYK2 target. Takeda Pharmaceutical’s contender, TAK-279, is a small molecule acquired from Nimbus Therapeutics. Earlier this year, Takeda reported Phase 2 data showing that at the two highest doses, 68% and 67% of patients respectively achieved PASI 75. Takeda said Tuesday it plans to advance this drug to Phase 3 testing in plaque psoriasis in its 2023 fiscal year. TYK2 is also attracting startups into the field, such as Sudo Biosciences and Neuron23.
Cross-trial comparisons are tricky, but investors and biotech companies make them anyway. In a prepared statement, Ventyx CEO Raju Mohan said VTX958’s results do not support further development of the molecule in “the highly competitive psoriasis and psoriatic indications.”
“While the Phase 2 trial of VTX958 in plaque psoriasis met the primary and key secondary endpoints, we are disappointed by the magnitude of efficacy observed, despite having achieved target levels of drug exposure in the trial,” he said.
VTX958 is not completely finished. Ventyx said an ongoing Phase 2 test in Crohn’s disease will continue to enroll patients. An interim efficacy analysis is planned for the first quarter of 2024. Also on track for updates in the first quarter are VTX002, an S1P1R modulators in Phase 2 testing for ulcerative colitis; the peripheral NLRP3 inhibitor VTX2735, which is in Phase 2 testing in familiar cold autoinflammatory syndrome; and brain-penetrating NLRP3 inhibitor VTX3232 in Phase 1 testing in healthy volunteers.
Shares of Ventyx opened Tuesday at $2.90 each, down more than 79% from Monday’s closing price. When Ventyx went public in 2021, it priced its shares at $16 apiece.
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