358MO - Quality-adjusted life-year and life-year estimates for patients with recurrent/metastatic squamous cell carcinoma of the head and neck in the combined positive score 1-19 subgroup treated with pembrolizumab +/- chemotherapy vs cetuximab-containing regimens

Background

KEYNOTE-048 (NCT02358031) compared pembrolizumab (P) +/- chemotherapy (CT) with cetuximab + platinum-based CT for patients with recurrent and/or metastatic (R/M) squamous cell carcinoma of the head and neck (SCCHN). The estimated effect size for PFS and OS varied by combined positive score (CPS) subgroup. Focusing on CPS 1-19, we performed (in)direct treatment comparisons to quantify differences in quality-adjusted life-year (QALY) and life year (LY) gains for P +/- CT vs. cetuximab-containing regimens, EXTREME and TPEx (CCRs).

Methods

Five published trials reporting relevant data were identified (KEYNOTE-048 [CPS 1-19], EXTREME [all patients, NCT00122460], TPEXTREME [all patients, NCT02268695], GORTEC [all patients, NCT01289522], and CHECKMATE-651 [all patients, NCT02741570]). To estimate QALY gains, parametric models were fitted to digitized OS and PFS data from each trial, extrapolated to a lifetime horizon and combined with published utility values, accounting for time-preference discount rates from an Italian perspective. We compared incremental QALYs and LYs for P +/- CT and P, vs. both CCRs for the CPS 1-19 subgroup.

Results

Applying parametric models with the best statistical goodness-of-fit scores, changing the source of data for CCRs yielded LY and QALY gains in the range of -0.63 to +0.60 and -0.35 to +0.39, respectively, when compared with P+CT. Versus P alone, the corresponding ranges were -0.72 to +0.50 (LYs) and -0.45 to +0.29 (QALYs).

Conclusions

Since variability in outcomes for CCRs has been observed between trials, incremental QALY and LY estimates for subgroup analyses differ depending on the trial data used to project them. Additional evidence from indirect comparisons could better inform the relative effectiveness of P +/- CT vs. CCRs, for patients with CPS 1-19 R/M SCCHN, with important clinical implications.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Merck Healthcare KGaA, Darmstadt, Germany.

Funding

Merck Healthcare KGaA, Darmstadt, Germany (CrossRef Funder ID: 10.13039/1000099450.

Disclosure

P. Ivanyi: Financial Interests, Personal, Advisory Role: BMS, Bayer, Clinsol, Deciphera, Eisai, EMD Serono Inc., EUSA Pharma, H5-Oncology, Ipsen, Merck Serono (Global), Metaplan, MSD, Onkowissen, Pfizer, Roche; Financial Interests, Personal, Invited Speaker: AIM, Apogepha, AstraZeneca, Astella, BMS, Bayer (+ Europe, Global), CORE2ED, Deciphera, DKG-Onkoweb, Eisai, EUSA Pharma, FoFM, Id-Institut, Ipsen (Europe), Merck Serono (+ Europe, Global), MSD, MedKom, MTE-Academy, MedWiss, New Concept Oncology, Onkowissen-tv.de, Pharma Mare, Pfizer, Roche, ThinkWired!, Schmitz-Communikation, StreamedUP!, Solution Academy, Vivantis; Financial Interests, Personal, Research Grant: AIO, AstraZeneca, BMS, GSK, Ipsen, Lilly, Merck Serono, Niedersächsische Krebsgesellschaft, Novartis, EUSA, Eisai, Pfizer, MSD, Roche, Stiftung Immunonkologie, Wilhelm Sander Stiftung; Financial Interests, Personal, Funding: BB-Biotech, BMS, Bayer, Deutsche Gesellschaft für Thoraxchirurgie, EUSA, EUSA, Merck, Pharma Mare; Non-Financial Interests, Personal, Member: Member of Germen Working Party Medical Oncology (AIO), Member of the German Cancer Society, ASCO Member, ESMO Member, Member of Oncological Working Party Hannover (OAK), Spokesman Interdisciplinary Working Party – Kidney Cancer (IAGN-DKG); Non-Financial Interests, Personal, Steering Committee Member: Immunooncology Cooperative Group (ICOG-H), Clinical Trial Steering Committee CCC-H. A. Bullement, J. Naik: Financial Interests, Personal, Affiliate: Delta Hat . M. Schlichting, C.P. Pescott: Financial Interests, Personal, Affiliate: Merck Healthcare KGaA.