Phase I study of apitolisib (GDC-0980), dual phosphatidylinositol-3-kinase and mammalian target of rapamycin kinase inhibitor, in patients with advanced solid tumors

Saoirse O. Dolly, Andrew J. Wagner, Johanna C. Bendell, Hedy L. Kindler, Lee M. Krug, Tanguy Y. Seiwert, Marjorie G. Zauderer, Martijn P. Lolkema, Doris Apt, Ru Fang Yeh, Jill O. Fredrickson, Jill M. Spoerke, Hartmut Koeppen, Joseph A. Ware, Jennifer O. Lauchle, Howard A. Burris, Johann S. De Bono

Research output: Contribution to journalArticlepeer-review

Abstract

Purpose: This first-in-human phase I trial assessed the safety, tolerability, and preliminary antitumor activity of apitolisib (GDC-0980), a dual inhibitor of class I PI3K, and mTOR kinases. Experimental Design: Once-daily oral apitolisib was administered to patients with solid tumors for days 1 to 21 or 1 to 28 of 28-day cycles. Pharmacokinetic and pharmacodynamic parameters were assessed. Results: Overall, 120 patients were treated at doses between 2 and 70 mg. The commonest ≥G3 toxicities related to apitolisib at the recommended phase 2 dose (RP2D) at 40 mg once daily included hyperglycemia (18%), rash (14%), liver dysfunction (12%), diarrhea (10%), pneumonitis (8%), mucosal inflammation (6%), and fatigue (4%). Dose-limiting toxicities (1 patient each) were G4 fasting hyperglycemia at 40 mg (21/28 schedule) and G3 maculopapular rash and G3 fasting hyperglycemia at 70 mg (21/28 schedule). The pharmacokinetic profile was dose-proportional. Phosphorylated serine-473 AKT levels were suppressed by ≥90% in platelet-rich plasma within 4 hours at the MTD (50 mg). Pharmacodynamic decreases in fluorodeoxyglucose positron emission tomography uptake of >25% occurred in 66% (21/32) of patients dosed at 40 mg once daily. Evidence of single-agent activity included 10 RECIST partial responses (PR; confirmed for peritoneal mesothelioma, PIK3CA mutant head-and-neck cancer, and three pleural mesotheliomas). Conclusions: Apitolisib exhibited dose-proportional pharmacokinetics with target modulation at doses ≥16 mg. The RP2D was 40 mg once-daily 28/28 schedule; severe on-target toxicities were apparent at ≥40 mg, particularly pneumonitis. Apitolisib was reasonably tolerated at 30 mg, the selected dose for pleural mesothelioma patients given limited respiratory reserve. Modest but durable antitumor activity was demonstrated.

Original languageEnglish (US)
Pages (from-to)2874-2884
Number of pages11
JournalClinical Cancer Research
Volume22
Issue number12
DOIs
StatePublished - Jun 15 2016
Externally publishedYes

ASJC Scopus subject areas

  • Oncology
  • Cancer Research

Fingerprint Dive into the research topics of 'Phase I study of apitolisib (GDC-0980), dual phosphatidylinositol-3-kinase and mammalian target of rapamycin kinase inhibitor, in patients with advanced solid tumors'. Together they form a unique fingerprint.

Cite this