CONDOR, CheckMate-141, and Keynote-040 included similar percentages of HPV-positive patients (28.1%, 25.6%, and 24.0%, respectively).32,33 In addition, 74.2% of patients had previously received cetuximab in CONDOR, and 61.3% had previously received cetuximab in CheckMate-141.33 Keynote-040 and CheckMate-141 did enroll all comers in terms of PD-L1 expression; therefore, some patients had high PD-L1 expression according to the specific algorithms used for those studies. The CONDOR study was not powered to compare the combination and monotherapy arms, but addition of tremelimumab did not appear to improve outcomes compared with single-agent durvalumab in patients with PD-L1Clow/negative disease. S3QEL 2 regimens. Abstract Importance Dual blockade of programmed death ligand 1 (PD-L1) and cytotoxic T-lymphocyte associated protein 4 (CTLA-4) may overcome immune checkpoint inhibition. It is unknown whether dual blockade can potentiate antitumor activity without compromising safety in patients with recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC) and low or no PD-L1 tumor cell expression. Objective To assess safety and objective response rate of durvalumab combined with tremelimumab. Design, Setting, and Participants The CONDOR study was a phase 2, randomized, open-label study of Durvalumab, Tremelimumab, and Durvalumab in Combination With Tremelimumab in Patients With R/M HNSCC. Eligibility criteria included PD-L1Clow/negative disease that had progressed after 1 platinum-containing regimen in the R/M setting. Patients were randomized (N?=?267) from April Rabbit Polyclonal to Cytochrome P450 17A1 15, 2015, to March 16, 2016, at 127 sites in North America, Europe, and Asia Pacific. Interventions Durvalumab (20 mg/kg every 4 weeks) S3QEL 2 + tremelimumab (1 mg/kg every 4 weeks) for 4 cycles, followed by durvalumab (10 mg/kg S3QEL 2 every 2 weeks), or durvalumab (10 mg/kg every 2 weeks) monotherapy, or tremelimumab (10 mg/kg every 4 weeks for 7 doses then every 12 weeks for 2 doses) monotherapy. Main Outcomes and Measures Safety and tolerability and efficacy measured by objective response rate. Results Among the 267 patients (220 men [82.4%]), median age (range) of patients was 61.0 (23-82) years. Grade 3/4 treatment-related adverse events occurred in 21 patients (15.8%) treated with durvalumab + tremelimumab, 8 (12.3%) treated with durvalumab, and 11 (16.9%) treated with tremelimumab. Grade 3/4 immune-mediated adverse events occurred S3QEL 2 in 8 patients (6.0%) in the combination arm only. Objective response rate (95% CI) was 7.8% (3.78%-13.79%) in the combination arm (n = 129), 9.2% (3.46%-19.02%) for durvalumab monotherapy (n = 65), and 1.6% (0.04%-8.53%) for tremelimumab monotherapy (n = 63); median overall survival (95% CI) for all patients treated was 7.6 (4.9-10.6), 6.0 (4.0-11.3), and 5.5 (3.9-7.0) months, respectively. Conclusions and Relevance In patients with R/M HNSCC and low or no PD-L1 tumor cell expression, all 3 regimens exhibited a manageable toxicity profile. Durvalumab and durvalumab + tremelimumab resulted in clinical benefit, with minimal observed difference between the two. A phase 3 study is under way. Trial Registration clinicaltrials.gov Identifier: “type”:”clinical-trial”,”attrs”:”text”:”NCT02319044″,”term_id”:”NCT02319044″NCT02319044 Introduction Approximately 60% of patients with head and neck squamous cell carcinoma (HNSCC) present with locally advanced or metastatic disease; survival rates are low and many will experience relapse with locoregional recurrence, S3QEL 2 and/or metastatic disease.1,2 Patients with disease progression after first-line combination chemotherapy with or without biologic therapy have poor prognoses and are typically treated with single agents (eg, methotrexate, docetaxel, or cetuximab), which yield objective response rates (ORRs) of 4% to 13%.3,4,5,6 Agents targeting the antiCprogrammed death 1 (PD-1)/programmed death ligand 1 (PD-L1) pathway have shown promising activity in recurrent/metastatic (R/M) HNSCC with 2 PD-1 monoclonal antibodies (mAbs) approved for treatment of patients with platinum-refractory R/M HNSCC.7,8,9,10 Durvalumab, a human IgG1 mAb that blocks PD-L1 binding to PD-1 and CD80, has also shown antitumor activity as monotherapy in R/M HNSCC. In a phase 1/2 study to evaluate durvalumab,11 an ORR of 11% was achieved with durvalumab monotherapy; in the Phase II Study of Durvalumab Monotherapy in Treatment of Recurrent or Metastatic Squamous Cell Carcinoma of the Head and Neck (HAWK),12 durvalumab demonstrated an ORR of 16.2% with a median duration of response of 10.3 months in patients.