A First-in-Human Phase I Study of Subcutaneous Outpatient Recombinant Human IL15 (rhIL15) in Adults with Advanced Solid Tumors

Clin Cancer Res. 2018 Apr 1;24(7):1525-1535. doi: 10.1158/1078-0432.CCR-17-2451. Epub 2017 Dec 4.


Purpose: Preclinical data established IL15 as a homeostatic factor and powerful stimulator of NK and CD8+ T-cell function, the basis for clinical testing.Experimental Design: A first-in-human outpatient phase I dose escalation trial of subcutaneous (SC) rhIL15 was conducted in refractory solid tumor cancer patients. Therapy consisted of daily (Monday-Friday) subcutaneous injections of rhIL15 for two consecutive weeks (10 total doses/cycle). Clinical response was assessed by RECIST. Pharmacokinetics of rhIL15 and immune biomarkers were evaluated.Results: Nineteen patients were treated with rhIL15 at dose levels of 0.25, 0.5, 1, 2, and 3 mcg/kg/day. Fourteen patients completed ≥ 2 cycles of therapy that was well tolerated. One serious adverse event (SAE), grade 2 pancreatitis, required overnight hospitalization. Enrollment was halted after a patient receiving 3 mcg/kg/day developed a dose-limiting SAE of grade 3 cardiac chest pain associated with hypotension and increased troponin. No objective responses were observed; however, several patients had disease stabilization including a renal cell carcinoma patient who continued protocol treatment for 2 years. The treatment induced profound expansion of circulating NK cells, especially among the CD56bright subset. A proportional but less dramatic increase was found among circulating CD8+ T cells with maximal 3-fold expansion for the 2 and 3 mcg/kg patients.Conclusions: SC rhIL15 treatment was well tolerated, producing substantial increases in circulating NK and CD8+ T cells. This protocol establishes a safe outpatient SC rhIL15 regimen of 2 mcg/kg/day dosing amenable to self-injection and with potential as a combination immunotherapeutic agent. Clin Cancer Res; 24(7); 1525-35. ©2017 AACR.

Trial registration: ClinicalTrials.gov NCT01727076.

Publication types

  • Clinical Trial, Phase I
  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural

MeSH terms

  • Adult
  • Aged
  • CD8-Positive T-Lymphocytes / drug effects*
  • Carcinoma, Renal Cell / drug therapy*
  • Drug Administration Schedule
  • Humans
  • Interleukin-15 / administration & dosage*
  • Kidney Neoplasms / drug therapy*
  • Killer Cells, Natural / drug effects*
  • Middle Aged
  • Outpatients
  • Recombinant Proteins / administration & dosage*
  • Treatment Outcome


  • IL15 protein, human
  • Interleukin-15
  • Recombinant Proteins

Associated data

  • ClinicalTrials.gov/NCT01727076