Phase I safety, pharmacokinetic and pharmacodynamic study of SAR245409 (XL765), a novel, orally administered PI3K/mTOR inhibitor in patients with advanced solid tumors
Mené sur 83 patients atteints d'une tumeur solide de stade avancé, cet essai de phase I évalue la toxicité, la dose maximale tolérée et l'activité antitumorale d'un composé appelé SAR245409, un inhibiteur de PI3K/mTOR par voie orale
Purpose: This phase I, first-in-human study evaluated the safety, maximum tolerated dose (MTD), pharmacokinetics (PK), pharmacodynamics and preliminary efficacy of SAR245409, an inhibitor of pan-Class I PI3K and mTOR, administered orally once or twice daily in patients with advanced solid tumors. Experimental Design: Eighty-three patients received SAR245409. Doses ranged from 15-120 mg twice daily, and 70-100 mg once daily. A 3+3 dose-escalation design was used to determine the MTD. Patients were evaluated for adverse events (AEs) and response. Assessments included PK, pharmacodynamic impact of SAR245409 on PI3K pathway signaling in hair sheath cells, skin and tumor, and characterization of tumor molecular alterations. Results: The MTDs were 50 mg twice daily and 90 mg once daily. The most frequent treatment-related AEs were nausea (36.1%), diarrhea (21.7%), vomiting (19.3%) and decreased appetite (16.9%). The most frequent treatment-related grade 3/4 AEs were increases in alanine aminotransferase (6.0%) and aspartate aminotransferase (4.8%). SAR245409 had a relatively short plasma half-life (2.96-7.52 hours). At MTDs, once- and twice-daily regimens yielded similar mean steady-state plasma exposure. A reduction in PI3K and mTORC1/mTORC2 pathway signaling was observed in serial hair sheath cells, skin and tumor samples. Best response was stable disease (SD) in 48% of evaluable patients; seven patients had minor tumor regression. Twelve patients with SD were treated for ≥16 weeks. No trend was observed correlating tumor molecular alteration with antitumor activity. Conclusions: SAR245409 had a manageable safety profile, demonstrated reduced PI3K and mTORC1/mTORC2 pathway signaling and was associated with clinically relevant SD.