Telitacicept Reduces SLE Severity in Phase 3 Trial in China

RemeGen is also sponsoring a similar Phase 3 trial in the US

Marisa Wexler, MS avatar

by Marisa Wexler, MS |

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Telitacicept, a B-cell-targeting therapy developed by RemeGen, outperformed a placebo at reducing the severity of systemic lupus erythematosus (SLE) in a Phase 3 clinical trial in China, the company announced.

“We are delighted with the news of the preliminary results of the Phase III confirmatory study of our proprietary novel fusion protein Telitacicept for the treatment of SLE in China,” Jianmin Fang, PhD, CEO and chief scientific officer of RemeGen, said in a press release.

Telitacicept, also known as RC18, is a fusion protein crafted by combining part of a cellular protein receptor with a fragment from an antibody protein. It’s designed to simultaneously block the activity of two proteins — BLyS (B-cell lymphocyte stimulator) and APRIL (a proliferation inducing ligand) — that play a key role in B-cell development.

By blocking these proteins, telitacicept aims to lower the inflammatory activity of B-cells, a type of immune cell with a central role in driving lupus and other autoimmune diseases. The therapy was conditionally approved to treat SLE in China in early 2021 and has been granted fast track status by the U.S. Food and Drug Administration.

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The Phase 3 trial enrolled 335 people with SLE. Participants were randomly assigned to receive telitacicept (160 mg) or a placebo, given via subcutaneous (under-the-skin) injection once weekly for 52 weeks (around one year). Both telitacicept and placebo were given on top of standard treatments.

The study’s main goal was to assess the proportion of patients who responded to treatment, as defined by a clinically significant improvement on a measure of global disease severity called Systemic Lupus Erythematosus Responder Index 4 (SRI-4).

In the primary analysis, the SRI-4 response rate was significantly higher among those treated with telitacicept than in those given a placebo (82.6% vs. 38.1%).

The primary analysis included multiple imputations for missing data. In other words, when data was missing, the primary analysis filled in results based on statistical extrapolations from data that was available. In a separate analysis where all missing data were assumed to be from non-responders, the response rate was still significantly higher with telitacicept compared with placebo (67.1% vs. 32.7%).

RemeGen is currently sponsoring a similarly designed Phase 3 trial (NCT05306574) that’s testing telitacicept against a placebo in people with SLE in the U.S. The trial is enrolling participants, ages 12 to 70, at locations in Texas, Florida, and California.

The company is also sponsoring an open-label Phase 1 trial (NCT05247203) testing multiple doses of telitacicept in adults with SLE at sites in China. Earlier this year, RemeGen was cleared to launch a clinical trial testing the therapy in children with SLE in China.

RemeGen is also investigating the therapeutic potential of telitacicept for other B-cell-driven diseases, including myasthenia gravis and primary Sjögren’s syndrome.

“Our focus has always been the prioritization of indications with high unmet medical needs and sizeable patient populations that can be addressed in the global market. [Immunoglobulin A nephropathy, primary Sjögren’s syndrome and myasthenia gravis] have been a major part of this focus and our portfolio of other indications for which Telitacicept could potentially be the first biologic therapy is expanding rapidly,” Fang said.