Trametinib, a MEK inhibitor, has proven to be a new standard-of-care option for patients suffering from recurrent low-grade serous carcinoma.

• In this international, randomized, open-label, multicenter, phase 2/3 trial, 260 eligible patients with recurrent low-grade serous carcinoma were assigned to the trametinib group (n=130) or the standard-of-care group (n=130).

• In the trametinib and standard-of-care groups, progression-free survival events were 101 [78%] and 116 [89%] respectively at the primary analysis, and median progression-free survival was 13·0 months vs 7·2 months, respectively (hazard ratio 0·48).

• Skin rash (17 [13%] of 128), anemia (16 [13%]), hypertension (15 [12%]), diarrhea (13 [10%]), nausea (12 [9%]), and fatigue (ten [8%]) were the documented most frequent grade 3 or 4 adverse events in the trametinib group.

• In the standard-of-care group, most frequent grade 3 or 4 adverse events comprised abdominal pain (22 [17%]), nausea (14 [11%]), anemia (12 [10%]), and vomiting (ten [8%]).

• No treatment-related deaths occurred.