Phase II trial of sagopilone, a novel epothilone analog in metastatic melanoma

Abstract

Background: Sagopilone is a novel fully synthetic epothilone with promising preclinical activity and a favourable toxicity profile in phase I testing.

Methods: A phase II pharmacokinetic and efficacy trial was conducted in patients with metastatic melanoma. Patients had measurable disease, Eastern Cooperative Oncology Group performance status 0-2, adequate haematological, and organ function, with up to 2 previous chemotherapy and any previous immunotherapy regimens. Sagopilone, 16 mg m⁻², was administered intravenously over 3 h every 21 days until progression or unacceptable toxicity.

Results: Thirty-five patients were treated. Sagopilone showed multi-exponential kinetics with a mean terminal half-life of 64 h and a volume of distribution of 4361 l m⁻² indicating extensive tissue/tubulin binding. Only grade 2 or lower toxicity was observed: these included sensory neuropathy (66%), leukopenia (46%), fatigue (34%), and neutropenia (31%). The objective response rate was 11.4% (one confirmed complete response, two confirmed partial responses, and one unconfirmed partial response). Stable disease for at least 12 weeks was seen in an additional eight patients (clinical benefit rate 36.4%).

Conclusion: Sagopilone was well tolerated with mild haematological toxicity and sensory neuropathy. Unlike other epothilones, it shows activity against melanoma even in pretreated patients. Further clinical testing is warranted.

Figure 1

Mean plasma concentration–time curve of sagopilone after single intravenous infusion of 16 mg m⁻² sagopilone over 3 h (N=9–10).

Figure 2

Progression-free survival (PFS) and overall survival (OS) in 33 evaluable patients.

Figure 3

Overall survival in patients with progressive disease vs patients with stable disease (N=21), partial treatment response, or complete treatment response as the best response to sagopilone (N=12).