title: A phase 1 study of the PI3Kδ inhibitor idelalisib in patients with relapsed/refractory mantle cell lymphoma (MCL).
abstract: Idelalisib, an oral inhibitor of phosphatidylinositol-3-kinase δ (PI3Kδ), was evaluated in a 48-week phase 1 study (50-350 mg daily or twice daily) enrolling 40 patients with relapsed or refractory mantle cell lymphoma (MCL). Primary outcome was safety and dose-limiting toxicity (DLT). Secondary outcomes were pharmacokinetic parameters, pharmacodynamic effects, overall response rate (ORR), progression-free survival (PFS), and duration of response (DOR). Patients without DLT and no evidence of disease progression after 48 weeks enrolled in the extension study. Patients had median age of 69 years (range, 52-83) and received median of 4 prior therapies (1-14); 17 of 40 patients (43%) were refractory to their most recent treatment. Median duration of idelalisib treatment was 3.5 months (range, 0.7-30.7), with 6 (15%) continuing extension treatment. Common grade ≥3 adverse events (AEs) included (total%/grade ≥3%) diarrhea (40/18), nausea (33/5), pyrexia (28/0), fatigue (25/3), rash (23/3), decreased appetite (20/15), upper respiratory infection (20/0), pneumonia (13/10), and alanine transaminase or aspartate transaminase elevations (60/20). ORR was 16 of 40 patients (40%), with CR in 2 of 40 patients (5%). Median DOR was 2.7 months, median PFS was 3.7 months, and 1-year PFS was 22%. These data provide proof of concept that targeting PI3Kδ is a viable strategy and worthy of additional study in MCL. This trial was registered at www.clinicaltrials.gov as #NCT00710528.
authors.affiliation: Department of Medicine, University of Wisconsin Carbone Cancer Center, Madison, WI;
authors.forename: Brad S
authors.initials: BS
authors.lastname: Kahl
authors.affiliation: Department of Medicine, Oregon Health and Sciences University, Portland, OR;
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Spurgeon
authors.affiliation: Department of Medicine, Weill Cornell Medical College, New York, NY;
authors.forename: Richard R
authors.initials: RR
authors.lastname: Furman
authors.affiliation: Sarah Cannon Research Institute, Nashville, TN;
authors.forename: Ian W
authors.initials: IW
authors.lastname: Flinn
authors.affiliation: Stanford University Medical Center, Stanford, CA;
authors.forename: Steven E
authors.initials: SE
authors.lastname: Coutre
authors.affiliation: Dana-Farber Cancer Institute, Boston, MA;
authors.forename: Jennifer R
authors.initials: JR
authors.lastname: Brown
authors.affiliation: Department of Medicine, Ohio State University, Columbus, OH;
authors.forename: Don M
authors.initials: DM
authors.lastname: Benson
authors.affiliation: Department of Medicine, Ohio State University, Columbus, OH;
authors.forename: John C
authors.initials: JC
authors.lastname: Byrd
authors.affiliation: Gilead Sciences, Seattle, WA; and.
authors.forename: Sissy
authors.initials: S
authors.lastname: Peterman
authors.affiliation: Gilead Sciences, Seattle, WA; and.
authors.forename: Yoonjin
authors.initials: Y
authors.lastname: Cho
authors.affiliation: Gilead Sciences, Seattle, WA; and.
authors.forename: Albert
authors.initials: A
authors.lastname: Yu
authors.affiliation: Gilead Sciences, Seattle, WA; and.
authors.forename: Wayne R
authors.initials: WR
authors.lastname: Godfrey
authors.affiliation: Department of Medicine, Washington University School of Medicine, St. Louis, MO.
authors.forename: Nina D
authors.initials: ND
authors.lastname: Wagner-Johnston
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D020522:Lymphoma, Mantle-Cell / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology; D008297:Male; D008875:Middle Aged; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011687:Purines / Q000494:pharmacology / Q000627:therapeutic use*; D052999:Quinazolinones / Q000494:pharmacology / Q000627:therapeutic use*; D012008:Recurrence; D012307:Risk Factors; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011687:Purines; D052999:Quinazolinones; C552946:idelalisib