Phase I single dose, two-period and two-sequence cross-over trial to evaluate the relative bioavailability of two oral pimasertib formulations in advanced cancer patients

Purpose: A phase I two-period two sequence cross-over study compared the bioavailability of two pimasertib (MSC1936369B/AS703026) formulations (capsule versus tablet) in advanced cancer patients. Methods: Patients with advanced solid tumors were randomized to one of two treatment sequences utilizing pimasertib tablet (test; 3 × 20 mg, PO QD) and capsule (standard; 2 × 30 mg, PO QD). The trial comprised a screening and baseline period, two time periods or parts A and B, and a trial extension phase. Results: N = 38 patients were randomized to two treatment sequences S1 and S2. PK parameters t_1/2, CL/f, and V_z/f were within the same range for the two formulations. Tablet had bioavailability comparable to capsule based on the analysis of AUC_0–t, however, tablet administration resulted in an increase of ~25% in C_max versus capsule. Common predicted adverse events of pimasertib included ocular events, diarrhea and creatine phosphokinase elevation. Disease control rate was ~29% with 1 partial response and 4 of 10 patients with stable disease >4 months. Conclusions: Pimasertib tablet was overall well tolerated, had a similar safety and efficacy profile to standard capsule formulation and had bioavailability comparable to capsule.