Comparative Bioavailability of a Single Dose of Trametinib (TMT212) Containing 9% Vs 11% Dimethyl Sulfoxide in Randomized Healthy Volunteers to Assess Long-Term Storage at Room Temperature

Storage of trametinib tablets outside of 2-8°C protected from moisture may lead to loss of dimethyl sulfoxide (DMSO) and adversely impact trametinib bioavailability. In this open-label, phase 1, single-dose, randomized, 2-treatment, 2-period crossover study in healthy volunteers, bioavailability of a single 2-mg tablet of trametinib containing 9% DMSO (test formulation), corresponding to the lowest DMSO content in the tablet after storage at 25°C for 36 months, was evaluated vs bioavailability of a 2-mg tablet containing 11% DMSO (reference formulation). Sixty-five percent of subjects (n = 39/65) were men, and mean (standard deviation) age was 45.6 (11.17) years. Time to reach maximum plasma concentration occurred at 1.5 hours after dosing. The geometric mean ratio (90%CI) comparing 2-mg trametinib containing 9% DMSO with 2-mg trametinib containing 11% DMSO for area under the concentration-time curve from time 0 to the last measurable plasma concentration sampling time was 0.890 (0.848-0.935), suggesting the 2 formulations have similar bioavailability. The majority of adverse events were mild, with 1 subject experiencing 1 grade 3 headache. These results indicated that storage of trametinib at room temperatures ≤25°C during the overall shelf life of 36 months would not negatively impact trametinib bioavailability.