Ianalumab

Astellas’ ASP5502 is one of the few molecules in the clinic targeting the STING pathway, which plays a key role in promoting inflammation.\n Astellas Pharma has become the latest company to pull back from a potential treatment for Sjögren’s syndrome, an autoimmune disease that still lacks any dedicated medicines.The Japanese drugmaker has terminated a phase 1 study of ASP5502, a small-molecule inhibitor of a protein called “stimulator of interferon genes” or STING. The cancellation “was a business decision and not related to safety or efficacy observed in the study,” an Astellas spokesperson told Fierce Biotech.The study, which enrolled 116 people, will complete its current cohort, the spokesperson added, while the future of ASP5502 “will be disclosed at the appropriate time.”The trial was designed in three parts. Part one was meant to test a single oral dose of the ASP5502 tablet in healthy volunteers, with part two then progressing to daily treatment for two weeks, also with healthy volunteers. Part three would then follow up with daily doses of the molecule for four weeks in patients with Sjögren’s syndrome.Astellas has completed the single-ascending dose and multiple-ascending dose portions of the trial, the spokesperson added. Sjögren’s syndrome is an autoimmune disease in which the patient’s immune system attacks the tear and salivary glands, leading to dry eyes and mouth. Those primary symptoms can also be accompanied by issues affecting the joints, nerves, lungs and other organs. Symptoms are typically managed with anti-inflammatory medications, but the FDA has never approved a drug specifically designed to treat Sjögren’s.Astellas’ trial termination follows other Big Pharmas that have ditched assets in the indication. At the beginning of 2025, Novartis gave up on an anti-CD40 antibody, iscalimab, that had shown some promise at treating Sjögren’s. The Swiss pharma is still pursuing a different antibody, ianalumab, for Sjögren’s and other autoimmune diseases. Ianalumab scored a breakthrough therapy designation from the FDA for Sjögren’s in January.Bristol Myers Squibb, Sanofi and Kiniksa Pharmaceuticals have all similarly stepped away from anti-CD40 antibodies for Sjögren’s in recent years.Astellas’ ASP5502 is one of the few molecules in the clinic targeting the STING pathway, which plays a key role in promoting inflammation. Other STING assets have also proven unsuccessful, with none surviving to phase 3 trials.The Sjögren’s setback comes mere weeks after Astellas nixed a $1.6 billion T-cell engager partnership with CytomX Therapeutics.Editor\'s note: This story was updated at 10:30 a.m. ET on March 31 with more information about the trial.

Astellas Pharma (Japan) has terminated its Phase I clinical trial of ASP5502, an oral small-molecule STING (Stimulator of Interferon Genes) inhibitor, in healthy adults and patients with primary Sjögren’s syndrome. The clinical trial terminated before completion, according to an updated record on ClinicalTrials.gov (NCT06544642), with the status verified as of March 2026. The study, which began enrolling participants in August 2024 at a Fortrea Clinical Research Unit in Daytona Beach, Florida, had been designed as a first-in-human evaluation of the compound. No results have been posted to the registry. The study was a randomized, double-masked, placebo-controlled Phase I trial with a three-part design: single ascending doses (including a food-effect cohort), multiple ascending doses in healthy volunteers over 14 days, and a 28-day repeated-dose cohort in adults with primary Sjögren’s syndrome without a placebo comparator. The trial planned to enroll 116 participants aged 18–65, with primary endpoints focused on safety and tolerability (adverse events, laboratory abnormalities, vital signs, and ECGs) and secondary endpoints assessing pharmacokinetics and cardiac safety. The Sjögren’s cohort required a diagnosis based on 2016 ACR-EULAR criteria and excluded patients receiving immunosuppressive or B-cell–targeting therapies or with other systemic autoimmune conditions. Termination context The study was terminated for strategic reasons, according to the ClinicalTrials.gov NCT06544642 entry, with no indication of safety concerns or lack of efficacy. The decision comes amid Astellas’ broader efforts to prioritize late-stage and core therapeutic areas, although the company has not publicly linked those changes to ASP5502 specifically. ASP5502 was positioned within Astellas’s immune homeostasis research area, which sits outside the company’s four declared primary focus areas: immuno-oncology, targeted protein degradation, genetic regulation, and blindness and regeneration. Astellas has been executing a systematic drug development pipeline update over the past two years, driven in large part by the approaching patent cliff for enzalutamide (Xtandi), its largest revenue-generating product, with generic competition expected around 2027. The company has concentrated resources on late-stage oncology assets — enfortumab vedotin (Padcev), zolbetuximab (Vyloy), and several degrader and antibody-drug conjugate programs — while pruning early-stage assets in non-core therapeutic areas. Prior discontinuations include a CAR-T program derived from the Xyphos acquisition and a KRAS G12D pancreatic cancer program (ASP4396), with the company recording approximately JPY 12.8 billion in discontinuation-related losses. A February 2025 management restructuring created a new Chief R&D Officer role consolidating oversight of research and development divisions, a move interpreted as tightening portfolio governance. AllSci lists no other active clinical trials for ASP5502, although Astellas has not confirmed the molecule’s discontinuation publicly. The Sjögren’s syndrome landscape Primary Sjögren’s syndrome affects an estimated 0.5% to 1.0% of the adult population, predominantly women, and is characterized by lymphocytic infiltration of exocrine glands leading to sicca symptoms — dry eyes and dry mouth — along with systemic manifestations including fatigue, arthralgia, and organ involvement. Despite its prevalence and burden, no therapy has received FDA approval specifically for the treatment of primary Sjögren’s syndrome. Current management relies on symptomatic relief and off-label use of immunosuppressants. The therapeutic landscape has seen repeated clinical failures. Bristol Myers Squibb’s abatacept did not meet its primary endpoint in a Phase III trial. Novartis tested ianalumab (an anti-BAFF receptor antibody) and reported mixed results, though development continues. GSK’s belimumab, approved for lupus, has been explored in Sjögren’s syndrome without regulatory success in that indication. Horizon Therapeutics (now Amgen) evaluated teprotumumab but in a different autoimmune context. The BAFF/APRIL axis, B-cell depletion, and T-cell co-stimulation blockade have all been pursued with limited translational success in this disease. STING inhibition represented a mechanistically distinct approach. The STING pathway, part of the innate immune system’s cytosolic DNA sensing machinery, has been implicated in the pathogenesis of several autoimmune conditions, including Sjögren’s syndrome, where aberrant type I interferon signaling is a recognized feature. Preclinical rationale for targeting STING in Sjögren’s syndrome rests on the observation that chronic activation of the interferon pathway contributes to glandular inflammation and tissue damage. However, translating STING pathway modulation into clinical benefit in autoimmune disease remains unproven, and ASP5502 was among the first oral STING inhibitors to enter human testing for this indication. Your email address will not be published. Required fields are marked * Comment * Name * Email * Website