888P - Clinical predictors for survival with the addition of chemotherapy in patients with recurrent-metastatic squamous cell carcinoma of the head and neck after progression on immune checkpoint inhibitors

Background

Immune checkpoint inhibitors (ICI) are standard of care in treating patients (pts) with recurrent-metastatic (R/M) head and neck squamous cell carcinoma (HNSCC), the majority will progress on ICI. Little is known regarding the impact of subsequent chemotherapy (SC) on outcomes in this population. We report a single institution retrospective analysis of pre-treatment characteristics and overall survival (OS) for pts with R/M HNSCC who received SC vs. those who received hospice only care (HOC) after progression on ICI.

Methods

We analyzed 154 pts with R/M HNSCC who progressed on ICI as a first or second line and beyond between January 15^th, 2016 and April 9^th, 2020. Pts received either SC or HOC after progression on ICI. OS was defined as the time between first day of SC or last day of ICI (for pts who received HOC) and death. Laboratory values were obtained on the day of starting SC or last day of ICI for pts who received HOC. Descriptive statistics and Cox regression were used to explore study variables.

Results

154 pts progressed on ICI, sex M/F: 121/33 (79%/21%). Median age: 61 (IQR: 53-66). Performance status (PS) 0/1: 93 pts (60%), PS 2/3: 61 pts (40%). Tumor site: oropharynx 64 (42%), oral cavity 34 (22%), others 56 (36%). P-16 status: negative 102 (66%), positive 52 (34%). ICI drug: pembro 79 (51%), nivo 69 (45%), ipi+nivo 6 (4%). 90 pts (58%) received HOC and 64 pts (42%) received SC. The most common SC was a combination of weekly carboplatin, paclitaxel and cetuximab 28 pts (44%), 36 pts (56%) received other SC. Median follow up: 8 months (mo) (IQR: 2-16). Pts who received HOC had shorter ICI treatment interval (1.9 mo vs 4.2 mo, p<0.001), higher incidence of negative P-16 (73% vs 56%, p=0.027), low hemoglobin (73% vs 42%, p<0.001), low albumin (54% vs 25%, p<0.001), and PS 2/3 (47% vs 30%, p=0.034). After adjusting for these variables, pts who received SC had better OS compared to pts who received HOC, median OS of 9 mo (CI: 5-13) vs 1 mo (CI: 1-3) p<0.001.

Conclusions

A group of pts with R/M HNSCC will benefit from SC after progression on ICI. ICI treatment interval, P-16, hemoglobin, albumin, and PS should be studied as potential markers for treatment selection in this population.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.