Lynk Pharmaceuticals Co., Ltd. ("Lynk Pharmaceuticals"), a clinical-stage innovative drug development company focused on immune and inflammatory diseases, announced that the New Drug Application (NDA) for its core product, zemprocitinib capsules, for the treatment of moderate-to-severe active rheumatoid arthritis (RA) was formally accepted by the Center for Drug Evaluation (CDE) of China's National Medical Products Administration (NMPA) on November 4. This acceptance marks the advancement of zemprocitinib into the regulatory review stage for rheumatoid arthritis, with the potential to offer a new oral treatment option for patients with an inadequate response to biologics.

The NDA submission is supported by positive results from a randomized, double-blind, placebo-controlled Phase III clinical trial conducted across multiple centers in China. The study enrolled 430 adult patients with moderate-to-severe active RA who had an inadequate response or intolerance to prior biologic disease-modifying antirheumatic drugs (bDMARDs). The study demonstrated statistically significant efficacy advantages for zemprocitinib over placebo across the primary and key secondary endpoints (p<0.0001), with an overall favorable safety and tolerability profile.

Long-term follow-up data further confirm the sustained clinical benefit of zemprocitinib. Among patients receiving continuous treatment through Week 76, ACR20 and ACR50 response rates were maintained at 91.8% and 80.5%, respectively, while the ACR70 response rate increased to 62.4%. Additionally, zemprocitinib demonstrated durable and consistent efficacy in disease activity endpoints (DAS28-CRP ≤3.2) and physical function improvements (HAQ-DI improvement ≥0.22).

Differentiated Advantage: Clinical Value of a Highly Selective JAK1 Inhibitor

Zemprocitinib is a second-generation, highly selective oral JAK1 inhibitor with best-in-class potential. Compared with earlier-generation JAK inhibitors with lower selectivity, zemprocitinib has greater selectivity for JAK1, potentially reducing safety risks associated with off-target effects while maintaining efficacy. Preclinical and clinical study results have shown that zemprocitinib can potently inhibit multiple JAK1-related inflammatory signaling pathways in a dose-dependent manner. Across completed or unblinded clinical studies, zemprocitinib has demonstrated an overall favorable safety and tolerability profile, with rates of serious adverse events and adverse events of special interest (AESIs) comparable to those in the placebo group, as well as favorable laboratory safety parameters.

Dr. Aik Goh, Chief Medical Officer of Simcere, said: "Treatment options are very limited for patients with RA who have an inadequate response to biologic therapies. The Phase III clinical data for zemprocitinib have demonstrated significant clinical benefits in this patient population. We look forward to working closely with Lynk Pharmaceuticals to bring this JAK1 inhibitor, with best-in-class (BIC) potential, to patients as soon as possible."

Dr. Zhao-Kui (ZK) Wan, Founder and CEO of Lynk Pharmaceuticals, said: "The acceptance of the NDA for zemprocitinib for the treatment of rheumatoid arthritis marks an important milestone for the company. The 76-week data are encouraging, demonstrating that zemprocitinib achieved favorable efficacy not only in patients who had an inadequate response to prior biologic disease-modifying antirheumatic drugs (bDMARDs), but also showed positive treatment effects in patients who had previously received JAK inhibitors. We look forward to working closely with regulatory authorities to advance the product toward approval and bring its benefits to more patients."