Phase II, open-label, randomized trial of the MEK1/2 inhibitor selumetinib as monotherapy versus temozolomide in patients with advanced melanoma

Abstract

Purpose: To compare the efficacy and tolerability of the mitogen-activated protein (MAP)/extracellular signal-regulated (ERK) kinase (MEK) 1/2 inhibitor selumetinib versus temozolomide in chemotherapy-naive patients with unresectable stage III/IV melanoma.

Experimental design: This phase II, open-label, multicenter, randomized, parallel-group study examined the effect of 100 mg oral selumetinib twice daily in 28-day cycles versus oral temozolomide (200 mg/m(2)/d for 5 days, then 23 days off-treatment). The primary endpoint was progression-free survival.

Results: Two hundred patients were randomized. Progression-free survival did not differ significantly between selumetinib and temozolomide (median time to event 78 and 80 days, respectively; hazard ratio, 1.07; 80% confidence interval, 0.86-1.32). Objective response was observed in six (5.8%) patients receiving selumetinib and nine (9.4%) patients in the temozolomide group. Among patients with BRAF mutations, objective responses were similar between selumetinib and temozolomide groups (11.1% and 10.7%, respectively). However, five of the six selumetinib partial responders were BRAF mutated. Frequently reported adverse events with selumetinib were dermatitis acneiform (papular pustular rash; 59.6%), diarrhea (56.6%), nausea (50.5%), and peripheral edema (40.4%), whereas nausea (64.2%), constipation (47.4%), and vomiting (44.2%) were reported with temozolomide.

Conclusions: No significant difference in progression-free survival was observed between patients with unresectable stage III/IV melanoma unselected for BRAF/NRAS mutations, who received therapy with selumetinib or temozolomide. Five of six patients with partial response to selumetinib had BRAF mutant tumors.

Figure 1

Patient disposition.

Figure 2

Comparison of PFS (A) and (C) and of TTD (B) and (D) between selumetinib and temozolomide in the overall population (A) and (C) and BRAF mutant patients (B) and (D). A, Kaplan–Meier comparison of PFS between selumetinib and temozolomide in the overall population (ITT population). B, Kaplan–Meier comparison of TTD between selumetinib and temozolomide in the overall population (ITT population). C, Kaplan-Meier comparison of PFS between selumetinib and temozolomide in the BRAF mutant subpopulation (ITT population). D, Kaplan–Meier comparison of TTD between selumetinib and temozolomide in the BRAF mutant subpopulation (ITT population).

Figure 2

Comparison of PFS (A) and (C) and of TTD (B) and (D) between selumetinib and temozolomide in the overall population (A) and (C) and BRAF mutant patients (B) and (D). A, Kaplan–Meier comparison of PFS between selumetinib and temozolomide in the overall population (ITT population). B, Kaplan–Meier comparison of TTD between selumetinib and temozolomide in the overall population (ITT population). C, Kaplan-Meier comparison of PFS between selumetinib and temozolomide in the BRAF mutant subpopulation (ITT population). D, Kaplan–Meier comparison of TTD between selumetinib and temozolomide in the BRAF mutant subpopulation (ITT population).