920P - Envafolimab plus chemoradiotherapy for locally advanced nasopharyngeal carcinoma (NPC), a prospective, single-armed phase II trial

Background

Gemcitabine plus cisplatin (GP) prior to concurrent chemoradiotherapy (CCRT) has favorable survival outcomes with acceptable toxicity in patients with locoregionally advanced nasopharyngeal carcinoma (LANPC). Immune checkpoint blockade therapy plus GP has been shown to improve the survival in recurrent or metastatic NPC. We aim to evaluate the efficacy and safety of envafolimab (PD-L1) with curative chemoradiotherapy in previously untreated LANPC.

Methods

In this single-arm, phase 2 study, eligible patients were of age 18-65, diagnosed with staged TxN2-3M0 or T4N1M0(AJCC 8^th) non-keratinizing LANPC. Enrolled patients received 3 cycles of intravenous gemcitabine (1000 mg/m², d1/8, Q3W)+cisplatin (80 mg/m², d1, Q3W), in combination with subcutaneous envafolimab injections (300mg, d1, Q3W) for induction chemotherapy, followed by CCRT, during which, every patient would receive 2 cycles of DDP (100 mg/m², d1, Q3W)+envafolimab (300mg, d1, Q3W). Then patients would receive envafolimab (300mg, d1, Q3W) for maintenance treatment for a year, until disease progression or intolerance of treatment. The primary endpoint was 3-year progress-free survival, the secondary endpoints included objective response rate (ORR), the disease control rate (DCR), locoregional failure-free survival, distant metastasis-free survival, and toxicity. All enrolled patients have finished induction chemotherapy treatment, the study is ongoing.

Results

From June 14th 2022 to December 13th, 2022, a total of 36 patients (median age 44y, 63.9% male) were enrolled at Sun Yat-sen University Cancer Center. As of May 4th, 2023, the median follow-up is 7.38 months. The ORR and DCR rate were 94.4%(95%CI: 81.3%, 99.3%) and 97.2%(95%CI: 85.5%, 99.9%).Compared to standard regimen, in combination with envafolimab did not increase the incidence of hematological toxicity events., and no irAEs for grade 3/4 were observed.. Long-term efficacy is awaited.

Conclusions

Envafolimab plus chemoradiotherapy was effective and safety in the treatment of LANPC. Further follow-up is needed to confirm the long-term efficacy.

Clinical trial identification

NCT05397769.

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Xiansheng.

Disclosure

All authors have declared no conflicts of interest.