Top-line results from the phase II study of CLR 131 – CLOVER-1

CLR 131 is a radioiodinated phospholipid ether-drug conjugate that utilizes malignant cells selective uptake and retention of phospholipid ethers. The use of CLR 131 is being investigated in the CLOVER-1 study in patients with relapsed/refractory (RR) B-cell hematologic cancers including multiple myeloma (MM). CLOVER-1 is an open-label, multicentre, phase II study. The top-line results from the study in patients with RRMM have been announced and are provided here.¹

Background on the study (NCT02952508)^1,2

• CLR 131 is being investigated in multiple B-cell hematologic cancers
• Enrolled patients with RRMM must have received at least 2 prior regimens including 1 proteasome inhibitor and 1 immunomodulatory agent
• Primary endpoints:
  • Clinical benefit response
  • Overall response rate (ORR)
  • Progression-free survival
  • Median overall survival
• Dose: 15.625 mCi/m² administered intravenously on days 1 and 8
  • Determined based on phase I results of cohort 5 (patients with RRMM)
• Patients also receive 40mg oral dexamethasone weekly for up to 12 weeks

Phase II top-line results¹

• Patients received a dose of 25 mCi/m² of CLR 131, administered as a single 30-minute infusion on days 1 and 8
• Median number of prior lines of therapy: 5
• Efficacy:
  • ORR (N = 10): 30%
  • Very good partial response: N = 1
  • Partial response: N = 2

The pharmaceutical company responsible for the trial continue to dose patients at higher fractionated doses with data from other cohorts expected to be announced later this year.