6052 Background: In patients with locally advanced oral squamous cell carcinoma (LAOSCC), major pathologic response (MPR) to induction therapy may translate into improved survival. The induction therapy using chemo-free drugs, such as the combination of anti-PD1 and anti-VEGFR drugs, has not been well issued in LAOSCC. Methods: A prospective single arm trial (NCT04393506) has been performed to evaluate the induction therapy of anti-PD1 and anti-VEGFR protocol in LAOSCC patients at clinical stage III and IVA. The patients received three cycles of intravenous Camrelizumab (PD-1 antibody, 200mg) on d1, d15, d29; and oral Apatinib (anti-VEGFR inhibitor, 250mg) daily, initiating on d1, ending on the 5th day before surgery. Radical surgery was planned on d42-d45. Post-operative radiotherapy was planned within 1.5 months after surgery, based on clinical and pathological stage. The primary endpoints were MPR and safety; primary tumors were assessed for the percentage of residual viable tumor that was identified on HE staining, and tumors with no more than 10% viable tumor cells were considered as MPR. This study has been approved by institutional ethics committee at Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine. Results: From April to December 2020, 21 patients were enrolled in this trial, and one patient withdraw from the trial at the beginning of treatment. The induction therapy was well-tolerated with no grade 3-4 toxicity or serve induction therapy-related AEs. One patient required surgery delay for 7 days due to unexplainable cTnI elevation. One patient put off Camrelizumab for 14 days due to grade 2 thrombocytopenia. One patient suspended Apatinib for 21 days due to grade 2 Hyperbilirubinemia. The induction therapy did not effect on the subsequent standard treatment. MPR rate was 40% (8/20), including 5% (1/20) pCR. Radiological evaluation of response to induction therapy showed 3 PR, 10 SD, 5 PD and 2 NA. Weak correlation was found between pathologic and radiological evaluation on induction therapy. Combined positive score (CPS) of PD-L1 expression in biopsy was evaluated in 19 patients; all 4 patients with CPS≥ 20 had MPR, 3 out of 11 patients with 1≤CPS < 20 had MPR, and 1 out of 4 patients with CPS < 1 had MPR. Conclusions: The chemo-free protocol of induction therapy using Camrelizumab and Apatinib is safe and well-tolerated for the patients with LAOSCC. The MPR rate is much higher using the anti-PD1 and anti-VEGFR protocol than the traditional induction chemotherapy protocol in LAOSCC. Clinical trial information: NCT04393506.
Correction to: Superselective intra-arterial chemoradiotherapy using altered blood flow compared to conventional systemic chemoradiotherapy for locally advanced oral squamous cell carcinoma: a single-center retrospective study