SAN DIEGO – A new randomized, double-blind, phase 3 study of the first-in-class drug telitacicept showed efficacy and safety in patients aged 18-65 with rheumatoid arthritis who were resistant to methotrexate, researchers reported at the annual meeting of the American College of Rheumatology.
Telitacicept is a recombinant fusion protein that aims to target and neutralize B lymphocyte stimulator (also known as B-cell activating factor) and a proliferation-inducing ligand (APRIL), both of which are linked to autoimmunity. Per the industry-funded trial, patients who took 160 mg weekly of the drug versus placebo for 24 weeks met the primary endpoint of achieving at least a 20% improvement in ACR response criteria (60.0% vs. 26.9%, respectively, P < .001), researcher Qing Zuraw, MD, MPH, MBA, of drug developer RemeGen, said in her presentation.
Rheumatologist Jeffrey A. Sparks MD, MMSc, of Brigham and Women’s Hospital and Harvard Medical School, both in Boston, who did not take part in the study but is familiar with the findings, said in an interview that the results are promising. “The magnitude of effect is impressive, and it seems it was well tolerated with relatively few serious adverse events. I would want to see this replicated in other patient populations. Also, more data are needed to truly establish safety.”
He added that, “once more data emerges, there would be a debate on where to place this in the treatment lines.”
According to Dr. Sparks, nearly half of patients with RA either cannot tolerate methotrexate or have partial or no response. “There are currently several available treatment options. These patients typically use either [tumor necrosis factor] inhibitors, another targeted medication, or combination therapy.”
Telitacicept is approved in China to treat systemic lupus erythematosus, Dr. Zuraw noted.
The researchers randomly assigned patients with moderate to severe RA at a 3:1 ratio to the drug (n = 360) or placebo (n = 119). The participants were aged 18-65 with a mean age of 49-50 depending on group, and 81.1%-87.4% females depending on group. Ethnicity/race was not reported.
At week 24, patients in the telitacicept group were more likely to achieve an ACR 50 response versus placebo (21.4% vs. 5.9%, respectively; P < .001).
“Significantly more patients in the telitacicept 160 mg group showed no radiographic progression (change in modified Total Sharp Score [mTSS] ≤ 0) at week 24, compared with placebo (90.2% vs. 66.4%; P < .001),” the researchers reported. “Additionally, patients in the telitacicept 160-mg group showed significantly less progression of joint damage (as measured by mTSS, joint space narrowing score, erosion score) from baseline to week 24.”
Treatment-emergent adverse effect levels were similar between the two groups (79.7% in the drug group and 77.3% in the placebo group), as were serious adverse events (6.4% and 6.7%, respectively) and infections/infestations (41.1% and 42.0%, respectively).
Dr. Zuraw noted limitations: The trial lacked a comparator treatment, and the study took place in a Chinese population with limited racial diversity.
In a Q&A session following Dr. Zuraw’s presentation, an audience member offered some perspective instead of a question by noting that most biologic drugs reach an ACR 20 response rate of about 60%, and most fail to move patients to low disease activity. “That’s the case for your product,” he told Dr. Zuraw. “That’s true for basically everything.”
He added that failing to discuss clinical importance is “a flaw of many talks.”
Dr. Zuraw responded that the many drugs do indeed have a response rate in the range of 60%, and she said the company will consider providing information about clinical impact in future talks.
No information is available about the potential cost of the drug. “This targets two proteins, so it is possible that it could have additional costs than typical biologics,” Dr. Sparks said.
RemeGen funded the study. Dr. Zuraw and some other authors disclosed financial relationships with RemeGen. Dr. Sparks reported receiving support from the National Institute of Arthritis and Musculoskeletal and Skin Diseases, the R. Bruce and Joan M. Mickey Research Scholar Fund, and the Gordon and Llura Gund Foundation; research support from Bristol-Myers Squibb; and consulting for AbbVie, Amgen, Boehringer Ingelheim, Bristol-Myers Squibb, Gilead, Inova, Janssen, Optum, Pfizer, Recor, Sobi, and UCB.