It was studied in a phase II trial in 30 patients that were HER2-positive (26 MUT, 4 AMP), with limited results in the HER2 MUT subgroup: ORR 12% (two patients with Ex20 insertion), mPFS 3 months, and mOS 9 months; with scarce tolerability, the most commons adverse events (AEs) reported were diarrhoea at 90% (grade 3 or greater [G ≥ 3] 23%) and skin rash at 73% (G ≥ 3 3%) [62]. The gene discussed is ERBB2; the disease is exanthem.