Telitacicept is both effective and safe among individuals with moderate-to-severe rheumatoid arthritis (RA) who are shown have to inadequately responded to methotrexate (MTX), according to late-breaking data presented at the American College of Rheumatology (ACR) 2023 Convergence in San Diego, California.¹

This trial data demonstrated the efficacy of the drug through ACR20, ACR50, and DAS28-ESR responses. The drug itself, known as telitacicept, is a recombinant fusion protein which was formulated to target and neutralize BLyS and APRIL.

The treatment was put under examination in this randomized, double-blind, phase 3 study. The investigators sought to look into the impact at a dosage of 160 mg versus the use of a placebo in among those with insufficient responses to MTX that had diagnoses of RA.

The study was presented by Qing Zuraw, MD, MPH, MBA, from RemeGen Biosciences in Wayne, Pennsylvania. Zuraw and colleagues used a randomized, placebo-controlled, double-blind study design and their research took place over 24 weeks.

The investigators later implemented an open-label follow-up to the treatment period which took place from week 25 - 48. Those with moderate-to-severe RA diagnoses who also reported a poor response to receiving MTX were recruited for the study.

These study subjects were randomized by the team into a 3:1 ratio, with the 2 different arms being given either 160 mg of telitacicept or a placebo once-per-week over the course of 24 total weeks. Following the end of the initial 24 week course, the participants who had first been assigned to the placebo arm were switched to telitacicept 160 mg once weekly for a further 24 week course.

The main efficacy endpoints used by the research team were aimed at the proportion of subjects reporting an ACR20 response at the 24-week mark. The secondary efficacy endpoints determined by the team included ACR50 and ACR70 response rates, DAS28-ESR, distinct components of the ACR response, and radiographic joint damage which was assessed by the mTSS at the 24-week mark.

The investigators ended up recruiting 479 total participants for this research, treating 360 with the drug and 119 with the placebo.

Overall, the team reported that both demographic data and disease qualities were found to be mostly similar between both arms of the study. The exception to these notable similarities was the higher CRP level in those treated with the drug compared to placebo (22.856 mg/L versus 17.287 mg/L, respectively).

A much higher percentage of subjects in the 160 mg treatment arm were shown to have reported an ACR20 response at 24 weeks compared to the placebo arm. The percentages worked out to be 60.0% versus 26.9%, respectively (P< 0.001), meaning that the drug achieved its primary endpoint.

The participants in the treatment arm were also shown to have a much greater number of subjects achieving ACR50 at 24 weeks, with 21.4% compared to 5.9% in the placebo group (P< 0.001). The investigators also found that reductions from the point of baseline in DAS28-ESR and individual components of the ACR criteria were shown to be much greater in the treatment arm as opposed to placebo.

Furthermore, a greater number of patients in the 160 mg treatment group were shown not to have radiographic progression (△mTSS ≤0) at the 24-week mark versus placebo, with 90.2% versus 66.4%, respectively (P< 0.001).

Furthermore, the investigators noted that there was far less progression of damage to joints in the treatment arm, as measured joint space narrowing score, by mTSS, and by erosion score, from baseline to 24 weeks. Both groups saw comparable scores of treatment-emergent adverse events (TEAEs), serious adverse events (SAEs), TEAEs resulting in discontinuation, and infections.

References

1. ^{L. Wang, D. Xu, Q. Zuraw, et al. Telitacicept, a Human Recombinant Fusion Protein Targeting and Neutralizing B Lymphocyte Stimulator (BlyS) and a Proliferation-Inducing Ligand (APRIL), in Rheumatoid Arthritis (RA) Patients with an Inadequate Response to Methotrexate (MTX): A Randomized, Double-Blind, Phase 3 Study. Presented at: American College of Rheumatology Convergence 2023. San Diego, CA. November 10-15, 2023.}