Efficacy of Anti-PD1 Blockade in Treating Recurrent or Metastatic Nasopharyngeal Cancer: A Systematic Review and Meta-analysis

Abstract

ObjectivesAnti-PD1 antibody has emerged as a promising immunotherapeutic option in patients with recurrent and/or metastatic nasopharyngeal cancers (RM-NPC). We aim to summarise existing evidence on the use of anti-PD1 antibodies in the treatment of these patients and compare its effectiveness with standard-of-care palliative chemotherapy. Our secondary aim is to explore potential combination therapies with anti-PD1 antibodies. Materials and MethodsPubMed, Embase and Cochrane databases were systematically searched for studies comparing the efficacy of various anti-PD1 antibodies in the treatment of RM-NPC (either as first or second line treatment) from inception to 2 September 2022. Meta-analyses were performed to correlate the various anti-PD1 antibodies with primary endpoints including overall response rate disease control rate (DCR), progression free survival (PFS) and overall survival (OS). ResultsEighteen studies with 1,887 patients met the inclusion criteria. The use of anti-PD1 antibody monotherapy as second-line treatment of RM-NPC revealed an ORR of 23 % (95 % CI = 19 %-28 %) and DCR of 51 % (95 % CI = 42 %-60 %). The ORRs for first-line as well as a combination of first and second-line treatments were 21 % (95 % CI = 15 % − 30 %) and 22 % (95 % CI = 6 % − 56 %, I2 = 75 %) respectively. The 12-month PFS and 12-month OS was also 27 % (95 % CI = 21 %–33 %) and 63 % (95 % CI = 53 %-72 %) respectively. ORR was much higher at 73 % (95 % CI = 32 %-94 %) when anti-PD1 antibodies were combined with Gemcitabine plus Cisplatin. ConclusionAnti-PD1 antibody demonstrate considerable activity in previously treated RM-NPC patients. Combining anti-PD1 antibodies with gemcitabine and cisplatin chemotherapy enhanced the efficacy of treatment.