MILAN – Results of a phase 3 trial with the investigational drug telitacicept show that patients with systemic lupus erythematosus have a significantly greater rate of response to SLE response criteria, compared with placebo, while results from a phase 2 trial of the drug in patients with primary Sjögren’s syndrome (pSS) also show significant improvements versus placebo.
“With only a limited number of treatments available for patients with lupus, this additional option is certainly an advance and the trial shows a strong efficacy result,” said Ronald van Vollenhoven, MD, PhD, who was not an investigator for either trial but presented the results for both at the annual European Congress of Rheumatology. He is professor of clinical immunology and rheumatology at Amsterdam University Medical Center and VU University Medical Center, also in Amsterdam.
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Dr. Ronald van Vollenhoven
Telitacicept is a recombinant fusion protein that targets B-lymphocyte stimulator and a proliferating-inducing ligand. It is currently undergoing testing in another phase 3 trial (REMESLE-1) at sites in the United States, Europe, and Asia. The current SLE results relate to the phase 3 study conducted in China, Dr. van Vollenhoven clarified.
SLE trial
The double-blind, placebo-controlled trial included 335 patients with SLE who had an average age of 35 years, a body mass index of 22-23 kg/m2, and a mean SELENA-SLEDAI (Safety of Estrogens in Systemic Lupus Erythematosus National Assessment–Systemic Lupus Erythematosus Disease Activity Index) score of at least 11.5, indicating high disease activity. Most patients were on glucocorticoids and immunosuppressants.
Patients were randomized 1:1 to weekly subcutaneous injections of telitacicept (160 mg; n = 167) or placebo (n = 168) in combination with standard therapy for 52 weeks. The primary endpoint was the SLE Responder Index-4 (SRI4) response rate at week 52, while key secondary endpoints included SELENA-SLEDAI, physician global assessment, and levels of immunologic biomarkers including C3, C4, IgM, IgG, IgA, and CD19+ B cells. Safety was also assessed.
At week 52, Dr. van Vollenhoven reported that significantly more patients taking telitacicept achieved a SRI4 response, compared with placebo, at 67.1% versus 32.7%, respectively (P < .001). “The difference was seen at 4-8 weeks and stabilized at around 20 weeks,” he said.
Time to first SLE flare was also reduced in patients on the trial drug at a median of 198 days (95% confidence interval, 169-254 days), compared with placebo at 115 days (95% CI, 92-140 days).
“The secondary outcomes also supported efficacy in these patients,” Dr. van Vollenhoven added, noting that there was a rapid and sustained increase of C3 and C4, the latter being significantly greater than placebo, and reduction of IgM, IgG, IgA, and CD19+ B cells observed following telitacicept treatment.
A significantly higher proportion of patients in the telitacicept group showed improvement in SELENA-SLEDAI at week 52, defined as a 4-point or greater reduction, compared with placebo (70.1% vs. 40.5%).
Telitacicept did not increase the risk of infections. Treatment-emergent adverse events occurred in 84.5% with telitacicept versus 91.6% with placebo, with infections (mostly upper respiratory) seen in 65.3% and 60.1%, respectively.