Monoclonal Antibodies Make Headway in Sjögren Treatment

VIENNA — Nipocalimab, iscalimab, and tibulizumab, but not lusvertikimab, appear to be promising new agents for Sjögren disease that warrant further investigation, suggest the results of four separate early clinical trials reported at the recent European Alliance of Associations for Rheumatology (EULAR) 2024 Annual Meeting.

This is potentially good news for patients, as discovering new treatments that work for managing the various symptoms of Sjögren disease is a high priority, Jacques-Eric Gottenberg, MD, PhD, said when he presented the results of the phase 2 DAHLIAS study of nipocalimab during a late-breaking abstract session.

“All patients suffer from high burden of symptoms — pain, fatigue, and dryness; nearly 50% of patients have systemic complications; mortality is increased, so there is a high unmet need since no specific drug has been accepted so far,” said Gottenberg, who works at Strasbourg University Hospital in Strasbourg, France.

“The pathogenesis of the disease involves high B-cell activation, resulting in high IgG levels, and secretion of autoantibodies,” such as anti-Ro, anti-La, anti-Sjögren’s syndrome type A (anti-SSA), and anti-Sjögren’s syndrome type B antibodies, Gottenberg said.

Thus, one approach to reducing the disease burden is to try to lower circulating immunoglobulin G (IgG) levels and IgG-associated autoantibodies, which is how the monoclonal antibody nipocalimab works. Nipocalimab essentially blocks the interaction of IgG with the neonatal fragment crystallizable receptor and has already been shown to have efficacy in other autoimmune conditions such as myasthenia gravis and fetal and neonatal hemolytic disease, although not as hoped in rheumatoid arthritis.

The DAHLIAS Phase 2 Study

Now, results from the DAHLIAS study show that nipocalimab may also work in Sjögren disease, with significant improvement vs placebo seen in the primary endpoint of the total EULAR Sjögren’s Syndrome Disease Activity Index (clinESSDAI) at 24 weeks for one of the two doses of the drug that were tested.

The multicenter, placebo-controlled, double-blind study was conducted in 163 patients with moderate to severely active primary Sjögren disease. The latter was determined by having a clinESSDAI of 6 or higher and seropositivity for anti-Ro60, anti-Ro52, or both autoantibodies.

Gottenberg reported that the mean age of patients was 48 years; the majority (92.6%) were women and of White ethnicity (90.8%). The baseline clinESSDAI was a mean of 9.9; 98.1% had anti-Ro60, 80.6% had anti-Ro52, and 71.9% had anti-La antibodies.

In addition to standard of care, patients were randomly allocated to receive intravenous treatment every 2 weeks with nipocalimab 5 mg/kg or 15 mg/kg, or placebo.

At 24 weeks, the least squares mean (LSM) change in clinESSDAI from baseline was −3.74 for placebo, −4.08 for nipocalimab 5 mg/kg (P = not significant vs placebo), and −6.40 for nipocalimab 15 mg/kg (P = .02 vs placebo).

Nipocalimab 15 mg/kg also “demonstrated similar and consistent trends in other key efficacy endpoints,” Gottenberg said. This included improvements in the ESSDAI and EULAR Sjögren’s Syndrome Patient Reported Index (ESSPRI) and composite measures such as the Sjogren’s Tool for Assessing Response (STAR), Composite of Relevant Endpoints for Sjogren’s Syndrome (CRESS), and the Disease Activity Level. There were also improvements in the unstimulated salivary flow rate.

Safety findings showed no new concerns, with adverse events reported in 62.5% of placebo-treated patients and by 79.2% and 79.6% of patients receiving nipocalimab 5 mg/kg and 15 mg/kg, respectively. Serious adverse events were reported in a respective 5.4%, 7.5%, and 7.4%, including severe infections or infections requiring intravenous anti-infectives in 1.8%, 3.8%, and 1.9% of participants, although none were thought to be related to the study treatment. No opportunistic infections or any deaths were reported.

Thomas Schindler, PhD, senior clinical scientist at F. Hoffmann-La Roche Ltd., in Basel, Switzerland, commented from the audience: “This was a very impressive set of results, and I’m very surprised that its safety profile is so benign.”

Schindler wanted to know if there were any changes in the serum albumin level and if this manifested as any laboratory abnormalities, but there were no reported cases of severe hypoalbuminemia in the study.

The TWINSS Phase 2 Study

Similarly hopeful results were reported for iscalimab, a fully human IgG1 anti-CD40 monoclonal antibody that is given by subcutaneous injection, during a clinical abstracts session. Xavier Mariette, MD, PhD, head of the Rheumatology Department at Bicêtre Hospital, Paris-Saclay University in Paris, France, reported updated results of the phase 2b dose-ranging TWINSS study, showing sustained benefits at 48 weeks. The primary endpoint results at 24 weeks were recently published in The Lancet.

TWINSS was set up to assess the safety and efficacy of iscalimab given every 2 weeks vs placebo in two distinct cohorts of patients with Sjögren disease — one with moderate to severe disease with both systemic and symptomatic involvement and the other with low systemic involvement but high symptom burden.

Whereas patients in the first cohort who had moderate to severe disease (n = 173) were randomly allocated to one of three doses (150, 300, and 600 mg) of iscalimab or placebo for the initial 24 weeks, those in the second cohort (n = 100) were randomly allocated to a 600-mg dose or placebo. After the double-blind period ended, patients taking iscalimab continued on the dose they were taking for another 24 weeks, with those in the placebo arms switching to the 600-mg dose in cohort 1 and the 300-mg dose in cohort 2.

Topline results for those in cohort 1 with moderate to severe Sjögren disease were that the significant improvements in ESSDAI that had been seen at week 24 were maintained in those who continued iscalimab and improved in those who had switched from placebo.

LSM change from baseline in ESSDAI vs placebo at week 24 had been −3.0, −1.4, and −2.9 for the 150-, 300-, and 600-mg doses of iscalimab, respectively. Results at week 48 were a respective −7.6, −5.7, and −7.9. The LSM change for the placebo-treated patients who had switched to the 600-mg dose was −6.7.

Mariette reported “consistent improvement” in patient-reported outcomes, including ESSPRI, the Sjögren’s Syndrome Symptom Diary, Functional Assessment of Chronic Illness Therapy-Fatigue measure, and the Impact of Dry Eye on Everyday Life instrument. There was also a significant improvement in stimulated salivary flow rates.

Similar benefits were seen in the second cohort of patients who did not have systemic involvement but had a high burden of symptoms, with improved ESSPRI scores of a LSM change from baseline vs placebo of −2.29 for patients continuing iscalimab 600 mg treatment and −1.14 for those taking the 300-mg dose after being treated with placebo. Improvements were also seen in the other patient-reported outcomes used.

Regarding safety, Mariette reported that there were “no specific issues” seen in the patients who switched from placebo to iscalimab, either at the 300-mg or 600-mg dose. Any adverse event occurred in around 80% of placebo-treated patients and roughly 90% of those given iscalimab, and serious adverse events occurred in 11.4%, 14.3%, and 11.4% pf patients treated with iscalimab 150, 300, and 600 mg, and 4.9% of those given placebo and then 600 mg iscalimab.

“The safety seems equivalent to patients having received iscalimab from the beginning of the trial,” Mariette said, adding “the risk-benefit [analysis] seems positive in patients up to week 48.”

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, 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,” Howell told Medscape Medical News. “We have potent engagement of the IL-17 and BAFF pathways, and that this sets the tone for additional exploration in rheumatologic diseases where there’s known activation of those two pathways,” he said.

Howell reported that total B-cell counts and lower levels of type 1 T helper cells were seen during the trial.

Over the years, 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 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, 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.

Fisher told Medscape Medical News: “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 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,” 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,” 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.”

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, 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.”

Fisher added that “the nipocalimab data looks interesting, as do data on TYK2 inhibition.”

The DAHLIAS study was funded by Janssen Research & Development. 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. Mariette has consulted for BMS, Galapagos, GlaxoSmithKline, Novartis, Pfizer, and Servier. The tibulizumab phase 1 study was funded by Eli Lilly & Company. Howell is an employee of the developer, Zura Bio. The Institut de Recherches Internationales Servier sponsored the lusvertikimab trial. 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.

Sara Freeman is a medical journalist and writer based in London. She is a regular contributor to Medscape Medical News, Medscape News UK, and other specialist healthcare media outlets.