Purpose: This first-in-human Phase I study investigated the safety, pharmacokinetics (PK), pharmacodynamic profile, and preliminary efficacy of CC-115, a dual inhibitor of mammalian target of rapamycin (mTOR) kinase and DNA-dependent protein kinase., Patients and Methods: Patients with advanced solid or hematologic malignancies were enrolled in dose-finding and cohort expansion phases. In dose-finding, once-daily or twice-daily (BID) ascending oral doses of CC-115 (range: 0.5-40 mg/day) in 28-day continuous cycles identified the maximum-tolerated dose for cohort expansion in 5 specified tumor types. Twelve additional patients with mixed solid tumors participated in a bioavailability substudy., Results: Forty-four patients were enrolled in the dose-finding cohort. Dose-limiting toxicity included thrombocytopenia, stomatitis, hyperglycemia, asthenia/fatigue, and increased transaminases. CC-115 10 mg BID was selected for cohort expansion (n=74) in which fatigue, nausea, and decreased appetite were the most frequent toxicities. Dose-proportional PK was found. CC-115 distributed to glioblastoma tissue (mean tumor/plasma concentration ratio: 0.713). Total exposure of CC-115 was similar under fasting and fed conditions. A patient with endometrial carcinoma remained in complete remission >4 years. Partial response (PR; n=2) and stable disease (SD; n=4) were reported in the bioavailability substudy; SD was reached in 53%, 22%, 21%, and 64% of patients with head and neck squamous cell carcinoma, Ewing sarcoma, glioblastoma multiforme, and castration-resistant prostate cancer, respectively. Chronic lymphocytic leukemia/small lymphocytic lymphoma showed 38% PR and 25% SD., Conclusion: CC-115 was well-tolerated, with toxicities consistent with mTOR inhibitors. Together with biomarker inhibition and preliminary efficacy, oral CC-115 10 mg BID is a promising novel anticancer treatment., Clinical Trial Registration: NCT01353625., Competing Interests: CM reports grants, personal fees and is a PI/CoPI for Amgen, Astella, Astra Zeneca, Bayer, BeiGene, BMS, Genentech, Janssen, Lilly, MedImmune, MSD, Novartis, Pfizer, Roche, Sanofi, Orion, and Abbvie; grants and is a PI/CoPI for Celgene, Debiopharm, Ipsen; is a PI/CoPI for Aduro, Agios, Argenx, Astex, AVEO, Blueprint, Boehringer Ingelheim, Chugai, Clovis, Daiichi Sankyo, Eisai, Exelixis, FORMA, GSK, Incyte, H3 Biomedicine, Innate Pharma, Kura Oncology, Loxo, Merus, Nektar Therapeutics, OCTIMET, Oncoethix, Pharmamar, Pierre Fabre, Servier, Taiho, Takeda, TESARO and Xencor, during the conduct of the study. LP-A reports personal fees from Roche, Lilly, Novartis, AstraZeneca, Boehringer Ingelheim, Amgen, Pfizer, MSD, BMS, Pharmamar and Takeda, outside the submitted work. DR reports grants from Gateway for Cancer Research and research funding from Celgene, during the conduct of the study. GB reports grants from Celgene, during the conduct of the study; grants, personal fees from Bristol-Myers Squibb, Bayer, Celgene, Merck, Genentech, Novartis, Xcovery, AstraZeneca, Roche, MedImmune, Clovis Oncology, Abbvie, ARIAD, Adicet, Amgen; grants from GlaxoSmithKline, Adaptimmune, Macrogenics, Kite Pharma, Immatics, Torque, Incyte, Exelixis, and Immunocore; personal fees from Maverick Therapeutics, outside the submitted work. DCS reports grants from Celgene, during the conduct of the study; grants from Medarex, Medivation, Eli Lilly & Co, Genentech, Astellas Pharma, Medimmune, Bayer HealthCare, Seattle Genetics, Millennium Pharmaceuticals, Incyte Pharmaceuticals, Novartis Pharma, F. Hoffman-La Roche AG, ESSA Pharmaceuticals, OncoMed Pharmaceuticals, Merck, outside the submitted work. BE reports personal fees from Celgene, during the conduct of the study; grants and personal fees from Roche, Janssen, Abbvie, Gilead, and personal fees from Novartis, outside the submitted work. TC reports grants and personal fees from Celgene, during the conduct of the study; In addition, Dr Cloughesy has a patent 62/819,322 pending; has received fees for consulting services from Tocagen, Karyopharm, GW Pharma, Kiyatec, Abbvie, Boehringer Ingelheim, VBI, Dicephera, VBL, Agios, Merck, Roche, Genocea, Celgene, Puma, Lilly, BMS, Cortice, Wellcome Trust, Novocure, Novogen, Boston Biomedical, Sunovion, Human Longevity, Insys, ProNai, Pfizer, Notable labs, and Media; has contracts with UCLA for Brain tumor program, Amgen, Abbvie, DNAtrix, BMS, AstraZeneca, Kazia, Agios, Boston Biomedical, Deciphera, Tocagen, Orbus, and Karyopharm; stock options with Notable Labs and is a Board member for 501c3: Global Coalition for Adaptive Research. DHF reports that one or more patent applications related to the work disclosed in this paper, may be planned, pending, and/or granted; is as an employee of Celgene and owns Celgene stock. SL is an employee of Celgene and owns stock. HR is an employee of Celgene. HdH reports personal fees from Celgene Corporation, during the conduct of the study. KH is an employee of Celgene and owns stock. JCB reports grants from Celgene, during the conduct of the study; grants and payment made to institution for consulting services and services as PI from Genentech/Roche, Bristol Myers Squibb, Five Prime, Lilly, Merck, MedImmune, Celgene, Taiho, Marcogenics, GSK, Novartis, OncMed, LEAP, TG Therapeutics, Astra Zeneca, BI, Daiichi Sankyo, Bayer, Incyte, Apexigen, Array, Sanofi, Agios, ARMO, Ispen, Merrimack, Oncogenex, Pieris, FORMA, Innate, Arch Oncology, Prelude Oncology, Amgen, Phoenix Bio; grants and payment made to institution for services as PI for EMD Serono, Koltan, SynDevRex, Forty Seven, AbbVie, Onyx, Takeda, Eisai, Celldex, Cytomx, Nektar, Boton Biomedical, Tarveda, Tyrogenex, Marshall Edwards, Pieris, Mersana, Calithera, Blueprint, Evelo, Merus, Jacobio, Effector, Novocare, Arrys, Tracon, Sierra, Unum Therapeutics, Vyraid, Harpoon, ADC, Pfizer, Millennium, Imclone, Acerta Pharma, Rgenix, Bellicum; grants and payment made to institution for consulting services from Cyteir, Molecular Partners, Torque, Tizona, Translational Drug Development, Seattle Genetics, Moderna Therapeutics, Tanabe Research Laboratories, Beigene, Continuun Clinical, outside the submitted work. PM, MM, AM, JN, TM, CC, and MH report no conflicts of interest in this work., (© 2019 Munster et al.)