A phase I trial of the HIV protease inhibitor nelfinavir in adults with solid tumors

// Gideon M. Blumenthal 1 , Joell J. Gills 3 , Marc S. Ballas 1 , Wendy B. Bernstein 1 , Takefumi Komiya 1 , Roopa Dechowdhury 1 , Betsy Morrow 1 , Hyejeong Root 1 , Guinevere Chun 1 , Cynthia Helsabeck 1 , Seth M. Steinberg 2 , Jaclyn LoPiccolo 1 , Shigeru Kawabata 3 , Erin R. Gardner 1 , William D. Figg 1 , Phillip A. Dennis 3 1 Medical Oncology Branch, National Cancer Institute, Bethesda, MD 2 Biostatistics and Data Management Section, National Cancer Institute, Bethesda, MD 3 Department of Oncology, Johns Hopkins School of Medicine, Baltimore, MD, USA Correspondence to: Phillip A. Dennis, e-mail: pdennis@jhmi.edu Key words: Nelfinavir, phase I clinical trial, AKT, endoplasmic reticulum stress, neuroendocrine Received: June 30, 2014      Accepted: August 28, 2014      Published: September 05, 2014 ABSTRACT Nelfinavir is an HIV protease inhibitor being repurposed as an anti-cancer agent in preclinical models and in small oncology trials, yet the MTD of nelfinavir has not been determined. Therefore, we conducted a Phase Ia study to establish the maximum tolerated dose (MTD) and dose limiting toxicities (DLT) of nelfinavir in subjects with advanced solid tumors. Adults with refractory cancers were given oral nelfinavir twice daily with pharmacokinetic and pharmacodynamic analyses. Twenty-eight subjects were enrolled. Nelfinavir was generally well tolerated. Common adverse events included diarrhea, anemia, and lymphopenia, which were mostly mild. The DLT was rapid-onset neutropenia that was reversible. The MTD was established at 3125 mg twice daily. In an expansion cohort at the MTD, one of 11 (9%) evaluable subjects had a confirmed partial response. This, plus two minor responses, occurred in subjects with neuroendocrine tumors of the midgut or pancreatic origin. Thirty-six percent of subjects had stable disease for more than 6 months. In peripheral blood mononuclear cells, Nelfinavir inhibited AKT and induced markers of ER stress. In summary, nelfinavir is well tolerated in cancer patients at doses 2.5 times the FDA-approved dose for HIV management and showed preliminary activity in tumors of neuroendocrine origin.