Written By: Pharmacally Medical News Desk
The U.S. Food and Drug Administration has granted Orphan Drug Designation to Envafolimab (also known as KN035) for the treatment of gastric cancer and gastroesophageal junction (GEJ) cancer. The designation was officially recorded on December 12, 2025, under the FDA’s orphan drug program, recognizing the drug’s potential benefit in these rare and serious cancers.
Orphan Drug Designation is aimed at encouraging development of treatments for conditions affecting fewer than 200,000 people in the U.S. It offers incentives such as seven years of market exclusivity upon approval, tax credits for clinical testing, waived FDA fees, and eligibility for accelerated review. This designation is a milestone for Envafolimab but does not by itself mean the drug has been approved for these cancers.
Envafolimab is a subcutaneously administered PD-L1 inhibitor developed through collaboration between Alphamab Oncology, 3D Medicines, and partners including Simcere. It is given by subcutaneous rather than by intravenous infusion, which can make treatment simpler and more accessible for patients who have difficulty with traditional IV therapy.
At the molecular level, Envafolimab is a single-domain antibody Fc fusion protein that blocks the interaction between PD-1 and PD-L1, proteins that tumors often use to suppress the immune system. By inhibiting this interaction, Envafolimab helps reactivate T cells and enhance the body’s immune response against cancer cells.
The FDA’s decision drew support from clinical data showing encouraging antitumor activity in patients with advanced gastric or GEJ cancer. In a Phase II study, Envafolimab combined with FOLFOX chemotherapy achieved an objective response rate (ORR) of 60% and a disease control rate (DCR) of 100% in treated patients, with a favorable safety profile and no treatment-related deaths reported.
These outcomes compare well with historical results seen in advanced stages of these cancers, where standard therapies typically yield modest responses and survival benefits. While more research is needed, the early signals suggest Envafolimab could offer a meaningful alternative or complement to existing treatment options.
This is the third FDA orphan designation for Envafolimab, following earlier designations in advanced biliary tract cancer and soft tissue sarcoma, reflecting a broader interest in exploring its immunotherapy potential across multiple challenging cancers.
Envafolimab’s Orphan Drug Designation highlights the FDA’s recognition of the unmet need in gastric and GEJ cancers and supports continued clinical development of the therapy. The designation does not imply approval, but it provides important incentives that may accelerate studies already underway. As additional data emerge from ongoing trials, the results will clarify Envafolimab’s potential role in treatment and whether its early signals of activity can translate into meaningful outcomes for patients.
References
Envafolimab Granted FDA Orphan Drug Designation for Gastric and GEJ Cancer, Simcare, 25 December 2025, https://en.simcere.com/news/detail.aspx?mtt=1561
Envafolimab, Orphan Drug Designations and Approvals, https://www.accessdata.fda.gov/scripts/opdlisting/oopd/detailedIndex.cfm?cfgridkey=1108425&utm_source=chatgpt.com