Systemic therapies for recurrent/metastatic nasopharyngeal carcinoma (RM NPC).

6031 Background: No randomized trials exist to guide clinical trial designs in RM NPC. As all published studies are single-arm trials, reliable historical progression-free survival (PFS) and overall survival (OS) data are not available. We aim to analyze existent literature to estimate the relative efficacy of available systemic regimens in RM NPC, as well as provide estimates of historical PFS and OS. Methods: We conducted a systematic search of MEDLINE, EMBASE and the Cochrane Library to March 2015. Clinical trials (in English only) investigating systemic therapies in adult patients (pts) with RM NPC were included. All relevant studies were assessed for quality using Downs and Blacks (DB) checklist (scored out of 27). Aggregate data analysis and student t-test were performed for all identified studies (model A). For studies that published analyzable Kaplan-Meier (KM) curves, survival data were extracted and marginal proportional hazards models were constructed (model B). Results: A total of 56 studies were identified and included in model A, 26 of which had analyzable KM curves and were included in model B. The 26 studies had significantly higher mean DB scores than the remaining 30 (17.3 [95% CI 15.5-19.0] vs 13.7 [95% CI 12.2-15.1], p = 0.002). For 2nd line+ pts, the estimated median OS [mOS] by model A is 11.5 mo (95% CI 10.1-12.9), while model B estimated this at 12.5 mo (95% CI 11.9-13.4). Table 1 presents the relative efficacy for first-line [FL] treatment regimens: combination [C] vs single-agent [S], and platinum [P] vs non-platinum [NP] based therapies. Conclusions: Our analysis supports the use of platinum-based combination chemotherapy in the first-line setting. We present the first aggregate estimates of OS for patients in 2nd line+ setting, which could inform the design of future clinical trials for RM NPC. Model A/mo (95% CI) P-value Model B/HR (95% CI) P-value FL C mPFS 8.4 (6.9-9.8) 0.007 0.48 (0.41-0.56) < 0.0001 FL S 3.5 (1.1-5.9) FL P mPFS 8.3 (7.0-9.6) 0.007 0.48 (0.41-0.56) < 0.0001 FL NP 3.5 (1.1-5.9) FL C mOS 17.8 (14.2-21.4) 0.020 1.16 (0.98-1.38) 0.084 FL S 8.2 (0.0-16.7) FL P mOS 17.4 (13.9-20.8) 0.023 1.16 (0.98-1.38) 0.080 FL NP 8.2 (0.0-16.7)