Abstract
Purpose: This Phase 1/2 study evaluated safety and efficacy of a topical submicron particle paclitaxel (SPP) in an anhydrous ointment base (SOR007), primarily in breast cancer patients with cutaneous metastases (CM).Methods: One of 3 concentrations of SOR007 SPP (0.15%, 1.0%, or 2.0%) was applied twice daily over an area of 50 cm2 under a 3+3 phase I design for up to 28 days, with the option for additional 28 days at the highest dose once safety was established. Efficacy was analyzed by lesion measurements and photographs to determine overall response rate (ORR), complete response (CR) and progression free survival by day 28 or 56.Results: Twenty-three subjects were enrolled, 21 with cutaneous metastases of breast cancer (CMOBC). Four subjects received SOR007 0.15%, three at a dose of 1.0% for a median of 28 days (range = 6 to 29 days), and sixteen at 2.0% for a median of 56 days (range = 42 to 60). All doses were well tolerated, and 19 subjects were evaluable for efficacy. At day 28 across all dose levels, 16% (95%CI: 3.4 to 39.6%) of subjects achieved an ORR and another 63.1% (95%CI: 34.9 to 96.8%) had stable disease (SD). The proportion of patients being progression free at 28 days across all treatments was 79% (95:CI: 54 to 94%). Conclusion: Application of SOR007 0.15%, 1.0%, and 2.0% to CM resulted in lesion stabilization or response in most subjects, with reduced lesion pain, and minimal systemic absorption of paclitaxel. A randomized, placebo-controlled trial to confirm these findings is warranted.NCT: #03101358