Zura Bio Limited (NASDAQ:ZURA) announced that its Phase 2 TibuSHIELD trial evaluating tibulizumab (ZB-106) in adults with moderate-to-severe hidradenitis suppurativa (HS) failed to meet its primary and key secondary efficacy endpoints.
The biotechnology company said neither the 300 mg nor the 150 mg dose achieved the study’s primary endpoint of percentage change from baseline in abscess and inflammatory nodule (AN) count at Week 16.
Secondary endpoints, including HiSCR50 and HiSCR75 response rates, were also not met. Following the results, Zura has decided to discontinue development of tibulizumab for hidradenitis suppurativa.
Phase 2 Trial Shows Limited Differences Versus Placebo
The randomised, double-blind, placebo-controlled TibuSHIELD study enrolled 247 adults with moderate-to-severe HS, evaluating two tibulizumab doses against placebo.
At Week 16, patients receiving the 300 mg dose experienced a 56.0% reduction in AN count, compared with 58.1% for the 150 mg group and 52.5% for placebo.
HiSCR50 response rates were 48.0% and 52.7% for the respective treatment groups, versus 45.5% for placebo.
HiSCR75 response rates reached 35.3% and 34.0%, compared with 28.1% in the placebo group.
Zura said it is conducting additional analyses to assess pharmacokinetic and pharmacodynamic findings, treatment exposure and disease-specific factors that may have influenced the results.
Safety Findings Consistent With Established Treatment Profiles
Both tibulizumab doses were generally well tolerated, according to the company, with safety findings consistent with the established profiles of IL-17 and BAFF inhibition.
Treatment-emergent adverse events were reported in 52.4% of participants in each tibulizumab group, compared with 46.3% receiving placebo.
Serious treatment-emergent adverse events occurred in 6.1% of patients receiving 300 mg, 3.7% receiving 150 mg and 1.2% receiving placebo.
One death from cardiac arrest occurred in the 300 mg group and was assessed by the site investigator as unrelated to treatment. An exacerbation of pre-existing inflammatory bowel disease was also reported in the same treatment group.
Development Continues in Systemic Sclerosis and Polymyalgia Rheumatica
Despite discontinuing the HS programme, Zura plans to continue evaluating tibulizumab in other autoimmune and inflammatory conditions.
The ongoing Phase 2 TibuSURE trial in systemic sclerosis is expected to report topline results during the first half of 2027.
The company also intends to initiate its Phase 2 NEXUS-PMR study in polymyalgia rheumatica by the end of 2026, with results anticipated in the fourth quarter of 2028.
Chief Executive Officer Sandeep Kulkarni said the company would continue investigating dual IL-17 and BAFF inhibition in systemic sclerosis and polymyalgia rheumatica, which involve different disease mechanisms from hidradenitis suppurativa.
Cash Position Expected to Support Operations Through 2028
Zura reported cash and cash equivalents of $187.7 million as of September 30, 2026.
The company expects its existing cash resources to fund planned operations through at least the end of 2028.
In addition to tibulizumab, Zura’s development portfolio includes torudokimab (ZB-880) and crebankitug (ZB-168), both of which have completed Phase 1/1b clinical studies.