Ventyx Bioscience has dropped its TYK2 inhibitor VTX958 after a Phase II Crohn’s disease trial missed its primary endpoint.  

The Phase II Harmony-CD trial (NCT05688852) failed to meet its primary endpoint of change in the mean Crohn’s disease activity index (CDAI) score from baseline to week 12 – a tool used to quantify the symptoms of Crohn’s. According to the 29 July announcement, this was due to a “higher than anticipated placebo response”. 

Shares of the California-based biotech had a 5.8% drop in share price when the markets opened on 29 July before levelling out to $2.28 before closing. 

The Phase II trial enrolled 109 patients randomised to one of two VTX958 doses or a placebo. Despite missing the primary endpoint, the trial showed that VTX958 did cause a dose-dependent effect on the key secondary endpoint of endoscopic response.  

However, Ventyx no longer plans to conduct additional clinical trials of VTX958 with internal resources, but said it intends to conduct further analysis to better understand the discordance between symptomatic and endoscopic response data. Ventyx had $279.7m cash available as of 30 June 2024, which is expected to last until H2 2026.  

It is not the first time that VTX958 has caused the company trouble. Data from a Phase II trial of the candidate in patients with moderate to severe plaque psoriasis was announced in November 2023, with the company saying that the “magnitude of efficacy observed” did not meet its internal target to support advancement of the programme. Despite meeting its primary endpoint, Ventyx dropped ongoing activities in the Phase II plaque psoriasis trial, as well as a Phase II trial of VTX958 in psoriatic arthritis. 

VTX-958 acts by inhibiting non-receptor tyrosine-protein kinase (TYK2). TYK2 controls the JAK-STAT pathway, which is overstimulated in many immune disorders. Bristol Myers Squibb’s TYK2-targeting Sotyktu (deucravacitinib) gained FDA approval in September 2022 to treat plaque psoriasis. GlobalData forecast that Sotyktu will generate $2.24bn in sales in 2030. 

GlobalData is the parent company of Clinical Trials Arena. 

The company’s focus will now move to its other candidates, which includes the ulcerative colitis candidate VTX002, which has been studied in a Phase II trial. Also in its pipeline is an obesity candidate, VTX3232, which is set to move into a Phase IIa study by the end of the year. Topline data are expected in the H1 2025.