Telitacicept Shows Promise in Primary Sjögren’s in Phase 2 Study
Telitacicept (RC18), an experimental therapy being developed by RemeGen, significantly eased disease activity in people with primary Sjögren’s syndrome in a Phase 2 clinical trial, the company announced.
“We are very excited to see the positive results from the Phase II clinical trial of telitacicept,” Jianmin Fang, founder and CEO of RemeGen, said in a press release. “Telitacicept has the potential to bring a new therapy to the patient population suffering from Sjögren’s syndrome, an autoimmune disease, to address an urgent clinical need.”
Sjögren’s syndrome is caused by the body’s immune system erroneously launching an inflammatory attack that damages healthy tissues, particularly the tear and salivary glands. According to RemeGen, the number of people living with Sjögren’s around the world is expected to exceed 4 million in the next few years.
Telitacicept is a man-made (synthetic) protein that contains pieces of two different proteins that have been attached together: a piece of an antibody called immunoglobulin G, and part of a protein called TACI, or human transmembrane activator and calcium modulator and cyclophilin ligand interactor.
The therapy is designed to treat people with autoimmune conditions such as Sjögren’s by blocking the activity of two disease-causing proteins — the lymphocyte stimulator (BLyS) and the A proliferation-inducing ligand (APRIL).
Both proteins are involved in the development and survival of mature B-cells and in the production of autoantibodies that contribute to autoimmune disorders. By modulating these cells’ activity, telitacicept is expected to reduce the inflammatory attack that drives Sjögren’s.
RemeGen’s Phase 2 clinical trial (NCT04078386), completed in October, had enrolled 42 people with primary Sjögren’s who were randomly assigned to receive a placebo or telitacicept at one of two doses (160 or 240 mg). Treatment was given via weekly under-the-skin (subcutaneous) injections, for 24 weeks or about six months.
The study’s main goal was to determine the impact of telitacicept on the European League Against Rheumatism (EULAR) Sjögren’s syndrome disease activity (ESSDAI) score, a measure of disease activity that assesses symptoms across a dozen different bodily systems. ESSDAI is the “gold standard” for measuring the Sjögren’s severity in trials, according to RemeGen.
Secondary goals included changes in other measures of disease activity, such as the EULAR Sjögren’s syndrome patient reported index (ESSPRI) and a Visual Analogue Scale score defined by patients and their healthcare practitioners. Changes in quality of life and fatigue were other secondary goals.
Results announced by the company showed the change in ESSDAI from the start of the trial to its end was significantly better in the lower-dose telitacicept group than in the placebo group. However, in the per-protocol-set analysis — which removes data from patients who failed to comply with the treatment protocol — both dosage groups were statistically different from the placebo group.
Yet, RemeGen did not specify the magnitude of difference in ESSDAI scores, nor discuss safety data in its announcement.