ArQule, Inc. announced that the first patient was dosed in the registrational MOSAIC (Miransertib in Overgrowth Syndromes in Adults and Children) trial of its oral, selective pan-AKT inhibitor, miransertib, for the treatment of Proteus syndrome (PS) and PIK3CA-related Overgrowth Spectrum disorders (PROS). The MOSAIC trial represents the first registrational trial of its kind for patients suffering from these rare genetic conditions characterized by mutations in the PI3K/AKT pathway that emerge in childhood and early adolescence. The MOSAIC trial is an international, multi-center, open-label study that will evaluate the objective response to miransertib in patients with PS and PROS. The study will enroll approximately 30-35 patients with documented somatic mutations in the AKT1 or PIK3CA genes in the registrational cohorts for PS and PROS. Thirty to 35 additional patients will be enrolled in 2 other cohorts for patients under compassionate use or those ineligible to enter the registrational cohorts.