Clinical Experience and Real-world Safety and Effectiveness of Envafolimab: Patient Access Program

Clinical Experience and Real-world Safety and Effectiveness of Envafolimab: Observational, Non-interventional Outcomes From a Multi-country Named Patient Access Program (ENCOMPASS STUDY)

Envafolimab is a novel PD-L1 inhibitor administered via subcutaneous (SC) injection - notably the first such checkpoint inhibitor approved for use worldwide.[1] In November 2021, Envafolimab received its first approval in China for adults with advanced microsatellite instability-high or mismatch repair-deficient (MSI-H/dMMR) solid tumors that have progressed after standard therapies. This SC route offers substantial practical advantages, significantly shortening treatment administration time and sparing patients from the adverse effects associated with intravenous infusions. Early clinical trials have demonstrated that Envafolimab can induce durable tumor responses, with objective response rates ~45% (including ~12% complete responses) observed in dMMR/MSI-H cancers. The therapy has also shown a favorable tolerability profile, with no infusion-related reactions and low rates of severe immune-mediated adverse events reported in initial studies.

The ENCOMPASS Study, designed to evaluate the real-world safety and effectiveness of Envafolimab in patients with advanced solid tumors. It is an observational, non-interventional, multicenter study sponsored by Glenmark Pharmaceuticals and will collect retrospective patient data from five countries: Kenya, Mauritius, Saudi Arabia, Philippines, and Sri Lanka. Approximately 120 adult patients treated under the Named Patient Program between June 2025 and December 2026 will be included. The primary endpoints focus on treatment effectiveness through Objective Response Rate (ORR), Disease Control Rate (DCR), Progression-Free Survival (PFS), and Overall Survival (OS). Secondary endpoints assess safety outcomes such as adverse events, serious adverse events, immune-related toxicities, and treatment discontinuation. Data will be gathered from anonymized medical records using electronic case report forms without any direct patient intervention. Statistical analysis will mainly be descriptive, with Kaplan-Meier methods used for survival outcomes. The study aims to generate evidence on Envafolimab use in non-Chinese populations where limited data currently exist. Ethical approvals, patient confidentiality, and regulatory compliance will be strictly maintained throughout the study.

Inclusion Criteria:

1. Adult patients (≥ 18 years) who received at least one dose of Envafolimab under the NPP between June, 2025 and Dec 31, 2026.
2. Histologically or cytologically confirmed diagnosis of a malignancy for which Envafolimab was prescribed under the NPP (e.g., an advanced solid tumor with MSI-H/dMMR or other approved/compassionate indications).
3. Measurable or evaluable disease at baseline, with at least one disease assessment (e.g. imaging or clinical evaluation) performed within 8 weeks before the first Envafolimab dose (to establish baseline tumor status).
4. At least one post-baseline disease assessment after starting Envafolimab, and a minimum follow-up duration of 6 months from the first dose (unless the patient has documented disease progression or died within 6 months).
5. Availability of sufficient clinical data in the medical records to evaluate baseline characteristics, treatment administration, tumor response, and safety outcomes. This includes baseline demographics, disease status, treatment dates, and follow-up assessments as required by the CRF.
6. Permission/approval for data use: Patient data can be utilized for research as per local ethical and regulatory requirements (e.g., institutional review board approval or waiver of consent for retrospective data collection, and compliance with data privacy laws).

Exclusion Criteria:

1. No evidence of Envafolimab administration: Patients for whom Envafolimab was requested or planned under NPP but never actually received a dose.
2. Insufficient follow-up: Patients with no post-baseline tumor assessment and less than 6 months of follow-up without documented disease progression or death. (Such patients would not contribute evaluable data for effectiveness.)
3. Missing critical baseline information in records, such as unknown index (start) date of Envafolimab therapy or lack of documented cancer diagnosis, precluding assessment of outcomes.
4. Prior Envafolimab exposure outside the NPP (e.g., via a clinical trial or other program) before the index date, unless specifically allowed (pre-specified exceptions, if any, will be outlined for instance, patients who switched from a clinical trial to NPP might be handled on a case by case basis).
5. Concurrent participation in any other interventional clinical trial at the time of starting Envafolimab (index date), to avoid confounding effects of other investigational treatments on outcomes.
6. Legal or ethical prohibitions on using the patient's data for research. For example, if local regulations or the patient's prior consent status prevent inclusion of their de-identified data in this study, they will not be enrolled.