OBJECTIVES: To characterize the treatment patterns of R/M SCCHN patients receiving first (1L) and second line (2L) PPBT in the pre-IO vs. post-IO eras.

METHODS: This retrospective cohort study of Symphony Health claims included adult patients with SCCHN initiating PPBT in the pre-IO era (August 2014 – July 2015) and post-IO era (August 2016 - July 2017); excluded patients with other malignancies, <1 month of follow-up, or on clinical trials.

RESULTS: Of 773 patients initiating 1L PPBT, 490 (63%) were treated post-IO, 214 (28%) received 2L PPBT. By cohort (pre- vs. post-IO) mean age at 1L PPBT was 59.0 vs. 61.4 years; lines of therapy per patient: 2.6 vs. 2.4; follow-up from platinum therapy (PT) start: 30.0 vs. 27.2 months; follow-up from 1L PPBT 18.1 vs. 9.1 months; 80% vs. 79% were male; 56% vs. 47% commercially insured.

Leading 1L PPBT therapies in the pre-IO era were PT retreatment (58%) and cetuximab (30%) with mean duration of treatment (mDoT) of 2.0 and 1.7 months, respectively. Post-IO, 41% 1L patients were retreated with PT, 43% received IO, 13% cetuximab with mDoT of 1.7, 3.7, and 2.3 months, respectively. In 2L pre-IO, 41% were retreated with PT, 23% received cetuximab, 15% methotrexate with mDoT of 1.6, 1.7, and 3.5 months. In 2L post-IO, 27% were retreated with PT, 47% received IO, 14% cetuximab with mDoT of 2.0, 2.6, 1.4 months. Altered regimens were used for patients receiving > 1 line of PT; 25% of 2L PPBT patients pre-IO vs. 9% post-IO received 3 lines of PT. Overall mDoT for 1L PPBT was 2.1 vs. 2.7 (p<0.001), 2L was 2.0 vs. 2.1 months (p=0.983).

CONCLUSIONS: Availability of IO has significantly changed the paradigms in 1L and 2L post-PT management of SCCHN yielding longer DoT. Longer follow-up is needed to evaluate IO impact on OS in real-world data.