925P - Efficacy of 2nd line treatment with chemotherapy (CT) or immune checkpoint inhibitors (ICIs) for patients (pts) with a prolonged objective response (>6 months) after 1st line therapy for recurrent or metastatic head & neck squamous cell carcinoma (R/M-HNSCC)

Background

Pts with R/M-HNSCC have a poor prognosis, and limited therapeutic options. ICIs have shown efficacy after progression within 6 months after platinum based chemotherapy (PBC) but no data concerning pts presenting tumor progression 6 months after the last dose of platinum for 1^st line R/M-HNSCC.

Methods

Retrospective analysis of all consecutive pts treated from 2008 to 2019 in 6 French centers for R/M-HNSCC with PBC as 1^st line and who had progression ≥6 months after last dose of platinum. Primary end-point was Progression-Free Survival (PFS) of 2^nd line. Additional end-points were Overall Survival computed from Day 1 of 1^st line (OS1) and survival computed from Day 1 of 2^nd line (OS2).

Results

A total of 144 pts were included with HNSCC of oropharynx (26%), hypopharynx (22%), larynx (17%), and oral cavity (33%). Six pts (15.8%) had HPV-related oropharyngeal HNSCC. At 1^st line pts received cisplatin (n= 67, 47%) or carboplatin (n= 77, 53%) and 129 pts (90%) received anti-EGF-R treatment. At 1^st line, complete response (CR), partial response (PR) and stable diseases (SD) occurred in 16 pts (11%) 77pts (53%) and 22 pts (15%) respectively. Ninety-five pts (66 %) received as second line a PBC, 25 pts another CT without platinum (17 %), and 24 and ICI (17 %). At 2^nd line start, ECOG was 0, 1 and, ≥2 for n=25 (17%), n=88 (61%), and n=28 (19%), respectively. The median PFS were 5.0 [3.78 – 6.22], 4.0 [0.99 – 7.00] and 2.0 months [0.41 – 3.59] for PBC, CT without platinum and ICIs respectively (p=0.942). OS 1 was 30, 23, and 29 months (p=0.06) and OS 2 was 14, 10, and 16 months (p=0.884) for PBC, CT without platinum, and ICI, respectively. PR occurred in 26%, 16% and 21%, CR in 0%, 8% and 4% and progression diseases in 21%, 44% and 54% for PBC, CT without platinum and ICI, respectively. For subsequent lines, ICIs was administered in 11 pts (12%) and 2 pts (8%) for PBC and CT without platinum respectively. Any predictive factor for PFS, OS was found.

Conclusions

This retrospective study suggested similar efficacy of chemotherapy or ICI as 2nd line therapy for patients progressing 6 months after the last dose of platinum in first line of R/M-HNSCC.

Clinical trial identification

Retrospective multicentric cohort

Editorial acknowledgement

NA

Legal entity responsible for the study

Daste.

Funding

Has not received any funding.

Disclosure

C. Borel: Honoraria (self), Advisory/Consultancy: BMS; Honoraria (self), Advisory/Consultancy, Travel/Accommodation/Expenses: Merck; Honoraria (self), Advisory/Consultancy, Travel/Accommodation/Expenses: AstraZeneca; Honoraria (self): MSD. F. Huguet: Advisory/Consultancy: BMS; Advisory/Consultancy: Merck; Advisory/Consultancy: MSD; Advisory/Consultancy: AstraZeneca; Advisory/Consultancy: Servier. E. Saada-Bouzid: Advisory/Consultancy, Travel/Accommodation/Expenses: BMS; Advisory/Consultancy, Travel/Accommodation/Expenses: AstraZeneca; Advisory/Consultancy, Travel/Accommodation/Expenses: MSD. J. Fayette, A. Daste: Advisory/Consultancy: BMS; Advisory/Consultancy: Merck; Advisory/Consultancy: MSD; Advisory/Consultancy: AstraZeneca. All other authors have declared no conflicts of interest.