A novel composite endpoint, sustained pain-free/no adverse events, was recently proposed as a more rigorous means of capturing in a single measure the attributes of migraine pharmacotherapy that patients consider most important: rapid and sustained pain-free response with no side-effects. Using pooled data from two replicate randomized, double-blind, parallel-group, placebo-controlled studies, this post hoc analysis compared the fixed-dose combination tablet sumatriptan/naproxen sodium (n ¼ 726) with sumatriptan monotherapy (n ¼ 723), naproxen sodium monotherapy (n ¼ 720), and placebo (n ¼ 742) with respect to sustained pain-free/no adverse events and closely related composite measures. Sustained painfree/no adverse events was defined as having both a sustained pain-free response from 2 through 24 hours post-dose with no use of rescue medication and having no adverse events within up to 5 days after dosing with study medication. The percentage of patients with sustained pain-free/no adverse events was 16% with sumatriptan/naproxen sodium compared with 11%, 9% and 7% for sumatriptan, naproxen sodium and placebo, respectively (p50.01 sumatriptan/naproxen sodium versus each other treatment). Sumatriptan/naproxen sodium was also significantly more effective than sumatriptan, naproxen sodium, and placebo for other composite endpoints including the percentages of patients with (1) sustained pain-free/no adverse events within 1 day; (2) sustained pain-free/no drug-related adverse events within up to 5 days; (3) sustained pain-free/no drug-related adverse events within 1 day; (4) sustained pain relief/no adverse events within up to 5 days; and (5) sustained pain relief/no adverse events within 1 day. The results demonstrate the superiority of sumatriptan/naproxen sodium to sumatriptan monotherapy, naproxen sodium monotherapy and placebo with respect to the rigorous and clinically relevant endpoint of sustained pain-free/no adverse events and reinforce the usefulness of utilizing this new composite endpoint.