Secukinumab is a fully human monoclonal antibody that selectively neutralizes IL-17A and shows long lasting efficacy and safety in plaque psoriasis. More evidence is required to optimize secukinumab dosing according to clinical response.GAIN compared the efficacy and safety of secukinumab 300 mg every two weeks (q2w) with 300mg every 4 weeks (q4w) in patients achieving PASI75 but not PASI90 after 16 weeks.772 patients with moderate to severe plaque psoriasis received secukinumab 300mg s.c. at baseline, Weeks 1, 2, 3 and 4, then q4w until Week 16. At Week 16, patients with PASI≥75 to PASI<90 were randomized 1:1 to continue q4w (n=162) or switch q2w (n=163) to Week 32. Primary endpoint was superiority of q2w to q4w dosing for PASI90 response at Week 32.PASI90 response at Week 32 was numerically greater with secukinumab 300mg q2w than with 300mg q4w in suboptimal responders, not reaching statistical significance (64.4% vs. 57.4%, OR0.64 95%CI[0.39, 1.07], p=0.087). Though the primary endpoint was not met, absolute PASI was significantly lower at Week 32 in q2w vs. q4w patients (2.14 vs.2.81, p=0.024). Significantly more patients with q2w vs. q4w dosing showed minimal disease activity (IGA0/1, 71.2% vs. 61.7%, p<0.05) and improved QoL (DLQI0/1, 58.9% vs. 50.5%, p<0.05) at Week 32. No new or unexpected safety signals arose.Most patients achieved PASI90 response with secukinumab q4w. There was potential benefit of q2w dosing in some suboptimal responders. Continued q4w treatment can improve response even after 16 weeks.