A differential response to cetuximab in patients with recurrent unresectable or metastatic head and neck cancer following immunotherapy (IO) exposure: An institutional experience
Ali HY, Rahman ZA, and Sheqwara J. A differential response to cetuximab in patients with recurrent unresectable or metastatic head and neck cancer following immunotherapy (IO) exposure: An institutional experience. J Clin Oncol 2019; 37.
J Clin Oncol
Background: Metastatic head and neck cancer is a diagnosis with poor prognosis and very little in terms of available active therapy. Until recently the mainstay of therapy was chemotherapy with or without cetuximab. The regimen of cetuximab (C), platinum (P) and 5FU has a response rate(RR) of 36% in the first line setting, and a PFS of 5.6 months and OS of 10.1 months. In the setting of post first line therapy immunotherapeutic agents (IO) have average RR of 15% and median OS of 8 months. Methods: We studied all patients with metastatic or recurrent head and neck cancer who were treated with an IO at our institution between May 2016 and July 2018 evaluating their entire history of therapy. 19 patient were treated with IO at our institution in the designated period of whom 9 received nivolumab (N) and 10 received pembrolizumab ( P ). Patients treated on trials were excluded. Patients who received less than 1 cycle of therapy were also excluded. 7 of the 19 patients received an IO in the first line setting after being refractory or resistant to platinum containing definitive therapy, 7 received the IO after a cetuximab (C) containing first line regimen, 1 patient received IO in second line but was naive to C and 4 received IO in the third line setting. Results: 3 of 19 patients treated with IO had partial response, there were no complete responses, 6 patients had stable disease as their best response and 10 patients progressed at the time of their first evaluation. 11 of 19 patients received additional therapy post IO. 10 patients received taxane based therapy 5 of whom the taxane was combined with C. Of the 5 patients who received a taxane and C combination 2 had CR, 2 had PR and one had PD. Of the 5 who received other taxane regimens, 1 had PR 1 had SD and 1 had PD, 2 expired prior to their first evaluation. The patient who received a non taxane regimen all had progressive disease. Of the 4 responding patients to C regimens 1 had SD during IO therapy and 3 had PD. The longest response duration to a C regimen post IO was 628 days. Conclusions: We observe an unusual response rate among patients treated with a combination of taxanes and cetuximab after IO therapy. This finding may relate to a modifying effect of IO on sensitivity to subsequent therapy. This observation merits further investigation.