Phase 1 Trial of Tibulizumab
Further positive early trial results were reported by Michael Howell, PhD, chief scientific officer for Zura Bio, a biotech company based in Henderson, Nevada. During a poster tour at EULAR 2024, Dr. Howell presented some preliminary findings from a phase 1 trial of tibulizumab, a dual antagonist of interleukin (IL)-17A and the B-cell–activating factor (BAFF) engineered by fusing elements of ixekizumab (Taltz) and tabalumab together.
“The headline result for me is that the molecule does what it’s supposed to,” Dr. Howell told this news organization. “We have potent engagement of the IL-17 and BAFF pathways, and this sets the tone for additional exploration in rheumatologic diseases where there’s known activation of those two pathways,” he said.
Dr. Howell reported that total B-cell counts and lower levels of type 1 T helper cells were seen during the trial.
Over the years, Dr. Howell, an immunologist, has been involved in the development of many therapeutics, such as risankizumab (Skyrizi) and spesolimab (Spevigo).
“When I look at the molecules and the opportunity we have to do broader antagonism of pathways in a safe aspect, this is probably one of the most exciting,” he said.
The trial he presented included 25 people with a confirmed diagnosis of Sjögren disease and anti-SSA or anti-SSB antibodies. Patients received tibulizumab or a placebo for a total of 12 weeks via a subcutaneous injection. Various doses were tested: 30 mg, 100 mg, or 300 mg every 4 weeks, or 300 mg every 2 weeks.
Serum levels of both BAFF and IL-17A increased as expected in the tibulizumab-treated patients, and Dr. Howell reported that “it’s well tolerated. There’s no adverse event profile that caused any concern.”
As a phase 1 study, it was not powered to look at efficacy, but there were positive signals, Dr. Howell said, meaning that the drug is likely to be tested further in a phase 2 trial.
Lusvertikimab Phase 2 Trial
During the same poster tour, the null findings of a phase 2 trial of the anti-IL-7 monoclonal antibody lusvertikimab were presented by Benjamin Fisher, MD, professor of rheumatology at Birmingham University in Birmingham, England.
Dr. Fisher told this news organization: “It’s a negative study, at least over the 3-month period that we’ve studied it.” Whether longer durations of treatment may be needed is a question that currently cannot be answered, he added.
A total of 48 patients with Sjögren disease had been included in the trial from 19 different centers in Europe, the United States, and Australia. The mean age of the participants was 53.7 years, 87% were women, and the mean duration of disease was 5.0 years. Baseline ESSDAI and ESSPRI were 12.1 and 7.0, respectively. Half were receiving other background treatment, and 72.9% were anti-Ro or anti-SSA positive.
Lusvertikimab 750 mg or a matching placebo was given via intravenous infusion at weeks 0, 2, 4, 7, and 10.
The primary endpoint was the mean change in ESSDAI from baseline to week 13, which was the same, at −3.9, in both groups. There was also no significant difference between the groups in any of the other secondary endpoints that were used, including ESSPRI, Schirmer’s test, the ocular staining score, salivary flow rate, physician and patient global assessment, assessment of fatigue, quality of life, or the composite measures STAR and CRESS.
“This isn’t going anywhere,” said Dr. Fisher, asking what was going to happen next and if this meant the end of IL-7-focused therapy.
“For years, there’s been quite a lot of interest in this,” Dr. Fisher said. Sjögren disease is characterized by a sort of focal inflammation of the saliva glands, which is composed of both T and B cells in the early stages, probably a T-cell component and a B-cell component, he explained.
“IL-7 is thought to be an important cytokine for homeostasis of the T-cell compartment, so for maintenance of T central memory and effector memory cells,” he said. “So, the idea is that, if you block IL-7, you switch off T cells, and you may rebalance the immune system towards a more regulatory phenotype. Just that it didn’t work,” Dr. Fisher said.
“There’s large unmet need,” he said. “Sjögren’s is associated with poor health-related quality of life, [and] a large part that is symptom-driven — dryness and fatigue — which we have no real interventions yet for patients; there’s no licensed therapeutics for it.”
Dr. Fisher cited ianalumab as one of the front-runners for becoming the first licensed treatment for Sjögren disease. The novel BAFF-targeting antibody is already in phase 3 trials and is also showing promise for the treatment of systemic lupus erythematosus.
“Then there are CD40-targeting drugs; the ones most advanced are dazodalibep and iscalimab.” Commenting on the potential of iscalimab, Dr. Fisher said that it “seems to work — it improves systemic disease activity; it also leads to some symptomatic improvement, which has been difficult to demonstrate in Sjögren’s.”
Dr. Fisher added that “the nipocalimab data looks interesting, as do data on TYK2 inhibition.”
The DAHLIAS study was funded by Janssen Research & Development. Dr. Gottenberg has consulted for AbbVie, Bristol Myers Squibb (BMS), Galapagos, Gilead, Janssen, Lilly, Merck Sharp & Dohme, Novartis, Pfizer, Sanofi, and UCB. The TWINSS study was funded by Novartis. Dr. Mariette has consulted for BMS, Galapagos, GlaxoSmithKline, Novartis, Pfizer, and Servier. The tibulizumab phase 1 study was funded by Eli Lilly & Company. Dr. Howell is an employee of the developer, Zura Bio. The Institut de Recherches Internationales Servier sponsored the lusvertikimab trial. Dr. Fisher has consulted for Novartis, Roche, BMS, Galapagos, Janssen, Servier, UCB, and Sanofi and received funding to his institution for collaborative research from Janssen, Celgene, Galapagos, and Servier.
A version of this article first appeared on Medscape.com.