Phase 3 Study: Canfosfamide (C, TLK286) plus carboplatin (P) vs liposomal doxorubicin (D) as 2nd line therapy of platinum (P) resistant ovarian cancer (OC)

Abstract

LBA5529 Background: Canfosfamide (C) is a novel glutathione analog prodrug activated by glutathione S-transferase P1–1. C has single agent activity in P resistant OC and is synergistic with P. Methods: Pts with P resistant OC following ≤ 2 P regimens, measurable disease (RECIST) were eligible. Pts received C (750 mg/m2) and P (AUC 5) or D (50 mg/m2) IV q4wks until progression. Randomization was stratified by ECOG PS, best prior P response and bulky disease (≥ 5cm). Results: All 247 P refractory or resistant pts received 505/494 cycles median 3 (range 1–17), CP/D respectively. Most common toxicities for CP were hematologic and as expected for each drug alone. By independent radiologic review (IRR), 25% of pts discontinued treatment without documented progression. Overall ORR varied between clinician and IRR assessments. Overall median PFS was 3.5 mos for both CP and D. Overall median survival (MS) has not been reached. Planned analysis of the effect of time from last P dose to study treatment (TFP; not from time of recurrence) identified a P resistant subgroup for TFP ≥ 6 mos (med 7.1) [ Table ]. Subgroup ORR for CP was 31.6% vs 10.5% for D. Subgroup median PFS for CP has not been reached vs 3.5 mos for D (p=0.0099). Subgroup MS for CP has not been reached vs 11.1 mos for D(p=0.0014). Subgroup CP had superior QOL outcomes per FACIT-FACT-O. Conclusions: Primary endpoint of overall PFS was comparable. Subgroup TFP ≥ 6 mos reported large differences in ORR and QOL and statistical significance in PFS and survival for CP. OC trials with C in combination with other standard agents are in progress. [Table: see text] [Table: see text]