RC18 Receives FDA’s Fast Track Designation for Treating SLE

The U.S. Food and Drug Administration (FDA) has granted fast track designation to RemeGen‘s RC18 (telitacicept) to treat people with systemic lupus erythematosus (SLE).

A therapy candidate is put on the FDA’s fast track program if it can treat serious conditions and fill an unmet clinical need, either because no treatments are currently available or because the potential treatment offers significant benefits over approved alternatives.

This designation, which comes on the heels of a $100 million private investment round, is meant to accelerate the development and review of RC18, facilitating discussions with the FDA and enabling the therapy to qualify for priority review and accelerated approval, provided that certain criteria are met.

“With limited treatment options available for patients, the Fast Track designation gives RemeGen the opportunity to help those impacted by offering a therapy with first-in-class and best-in-class potential,” Jianmin Fang, PhD, the company’s founder and CEO , said in a press release.

RC18 is a man-made protein designed to treat people with autoimmune conditions, such as SLE, 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 — which wrongly attack the body’s own cells and tissues — associated with autoimmune disorders.

A pivotal Phase 2b clinical trial (NCT02885610), which included 249 adults with moderate-to-severe SLE, aimed to determine if RC18 plus standard treatment was better at reducing disease activity than standard treatment alone.

Participants were assigned randomly to one of three RC18 doses — 80 mg, 160 mg or 240 mg — or to a placebo, administered weekly for 48 weeks.

Results showed that meaningful reductions in disease activity were more frequent in patients receiving RC18 (68.3% to 75.8% in the three dose groups) compared to those on placebo (33.9%). Safety assessments also showed a good tolerability profile for RC18 in this population.

Based on the findings, RemeGen has a filed a new drug application in China.

The company now is conducting a Phase 3 trial (NCT04082416, and still recruiting) in a larger group of SLE patients with moderate-to-severe disease.

The study is expected to include 318 participants, who will be assigned randomly to RC18 (160 mg) or a placebo while continuing their stable SLE treatment. Treatment will be given weekly for 52 weeks (one year), and as it was in the Phase 2 trial, injected subcutaneously (under-the-skin).

The primary measure of effectiveness is a meaningful reduction in disease activity — defined as a drop of four or more points in SLE Responder Index 4 (SRI4) scores from the study’s start to week 52.

Changes in other measures of disease activity, such as the Safety of Estrogens in Lupus National Assessment-Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI) or the Physician’s Global Assessment, also will be examined. Top-line data is expected by late 2021.