A phase 1 study of the PI3Kd inhibitor idelalisib in patients with relapsed/refractory mantle cell lymphoma (MCL)

Brad S. Kahl, Stephen E. Spurgeon, Richard R. Furman, Ian W. Flinn, Steven E. Coutre, Jennifer R. Brown, Don M. Benson, John C. Byrd, Sissy Peterman, Yoonjin Cho, Albert Yu, Wayne R. Godfrey, Nina D. Wagner-Johnston

Research output: Contribution to journalArticle

172 Scopus citations


Idelalisib, an oral inhibitor of phosphatidylinositol-3-kinase d (PI3Kd), 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 receivedmedian 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. Commongrade ≥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 PI3Kd is a viable strategy and worthy of additional study in MCL. This trial was registered at www.clinicaltrials.gov as #NCT00710528.

Original languageEnglish (US)
Pages (from-to)3398-3405
Number of pages8
Issue number22
StatePublished - May 29 2014


ASJC Scopus subject areas

  • Biochemistry
  • Immunology
  • Hematology
  • Cell Biology

Cite this

Kahl, B. S., Spurgeon, S. E., Furman, R. R., Flinn, I. W., Coutre, S. E., Brown, J. R., Benson, D. M., Byrd, J. C., Peterman, S., Cho, Y., Yu, A., Godfrey, W. R., & Wagner-Johnston, N. D. (2014). A phase 1 study of the PI3Kd inhibitor idelalisib in patients with relapsed/refractory mantle cell lymphoma (MCL). Blood, 123(22), 3398-3405. https://doi.org/10.1182/blood-2013-11-537555