Faculty Collaboration Database

First-in-Human Phase I Study of GSK2126458, an Oral Pan-Class I Phosphatidylinositol-3-Kinase Inhibitor, in Patients with Advanced Solid Tumor Malignancies. Clin Cancer Res 2016 Apr 15;22(8):1932-9

Date

11/26/2015

Pubmed ID

26603258

DOI

10.1158/1078-0432.CCR-15-1665

Scopus ID

2-s2.0-84966292102 (requires institutional sign-in at Scopus site)   75 Citations

Abstract

PURPOSE: GSK2126458 (GSK458) is a potent inhibitor of PI3K (α, β, γ, and δ), with preclinical studies demonstrating broad antitumor activity. We performed a first-in-human phase I study in patients with advanced solid tumors.

MATERIALS AND METHODS: Patients received oral GSK458 once or twice daily in a dose-escalation design to define the maximum tolerated dose (MTD). Expansion cohorts evaluated pharmacodynamics, pharmacokinetics, and clinical activity in histologically and molecularly defined cohorts.

RESULTS: One hundred and seventy patients received doses ranging from 0.1 to 3 mg once or twice daily. Dose-limiting toxicities (grade 3 diarrhea,n= 4; fatigue and rash,n= 1) occurred in 5 patients (n= 3 at 3 mg/day). The MTD was 2.5 mg/day (MTD with twice daily dosing undefined). The most common grade ≥3 treatment-related adverse events included diarrhea (8%) and skin rash (5%). Pharmacokinetic analyses demonstrated increased duration of drug exposure above target level with twice daily dosing. Fasting insulin and glucose levels increased with dose and exposure of GSK458. Durable objective responses (ORs) were observed across multiple tumor types (sarcoma, kidney, breast, endometrial, oropharyngeal, and bladder cancer). Responses were not associated withPIK3CAmutations (OR rate: 5% wild-type vs. 6% mutant).

CONCLUSIONS: Although the MTD of GSK458 was 2.5 mg once daily, twice-daily dosing may increase duration of target inhibition. Fasting insulin and glucose levels served as pharmacodynamic markers of drug exposure. Select patients achieved durable responses; however,PIK3CAmutations were neither necessary nor predictive of response. Combination treatment strategies and novel biomarkers may be needed to optimally target PI3K.

Author List

Munster P, Aggarwal R, Hong D, Schellens JH, van der Noll R, Specht J, Witteveen PO, Werner TL, Dees EC, Bergsland E, Agarwal N, Kleha JF, Durante M, Adams L, Smith DA, Lampkin TA, Morris SR, Kurzrock R

Author

Razelle Kurzrock MD Center Associate Director, Professor in the Medicine department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Administration, Oral
Adult
Aged
Aged, 80 and over
Antineoplastic Agents
Class I Phosphatidylinositol 3-Kinases
Drug Monitoring
Female
Humans
Male
Maximum Tolerated Dose
Middle Aged
Neoplasm Staging
Neoplasms
Pyridazines
Quinolines
Risk Factors
Sulfonamides
Treatment Outcome
Young Adult