phosphomannopentaose-sulfate and Thrombocytopenia

Treatment options for advanced melanoma are limited. PI-88, a potent inhibitor of heparanase, demonstrates anitangiogenic properties and has shown activity against melanoma in phase I studies. This was an open-label, multicenter, phase II study of PI-88 in patients with advanced melanoma. Patients received a fixed-dose of 250 mg/day given subcutaneously for four consecutive days followed by three drug-free days per week in a 28-day cycle. A total of 44 patients were enrolled in the intent to treat population, with 59.1% having received previous therapy. The median time to progression and overall survival was 1.7 months and 9 months, respectively. Forty-one patients are included in the efficacy analysis. One (2.4%) patient achieved a partial response, six (14.6%) patients had stable disease as best response, and 30 (73.2%) had progressive disease. At the end of six cycles of treatment, three of the 41 evaluable patients had non-progressive disease. Treatment was generally well tolerated. Injection site bruising occurred in 45% of patients. Serious bleeding did occur in two patients and three patients developed a positive anti-platelet antibody test during the study. One of these four patients experienced an associated thrombosis. In patients with advanced melanoma, PI-88 demonstrates an overall survival and time to progression similar to standard chemotherapy. Although the current study did not meet the primary end-point of progression free survival of >or=20%, there is some evidence of activity and further investigation is warranted.

Topics: Adult; Aged; Alanine Transaminase; Contusions; Drug Administration Schedule; Fatigue; Female; Glucuronidase; Humans; Injections, Subcutaneous; Kaplan-Meier Estimate; Male; Melanoma; Middle Aged; Nausea; Neoplasm Metastasis; Oligosaccharides; Pain; Severity of Illness Index; Thrombocytopenia; Treatment Outcome

The novel molecule PI-88 is a highly sulfonated oligosaccharide which inhibits heparanase activity and competes with heparan sulfate binding of growth factors such as FGF and VEGF. Preclinical data demonstrates that PI-88 inhibits angiogenesis and has anti-metastatic effects. The aim of this phase I study was to determine the recommended dose and toxicity profile of PI-88.. PI-88 was given intravenously in increasing duration of administration (0.57 mg/kg for 2 h, 0.57 mg/kg/day for 1 day, 4, 7 and 14 consecutive days) and then increasing dose for 14 consecutive days (1.14 mg/kg/day and 2.28 mg/kg/day) in patients with advanced malignancies until dose-limiting toxicity (DLT) was observed. Fourteen assessable patients with advanced malignancies received PI-88 intravenously.. DLT was thrombocytopenia. The thrombocytopenia appeared to be immunologically mediated with the development of anti-heparin platelet factor 4 complex antibodies. There were no other significant toxicities. At the final dose and schedule (2.28 mg/kg/day for 14 days), there was limited evidence of biological activity as measured by the surrogate marker activated partial thromboplastin time (APTT), although two patients had stabilisation of disease.. In conclusion, PI-88 at a dose of 2.28 mg/kg/day for 14 days resulted in dose-limiting thrombocytopenia which appeared to be immune related. Limited evidence of biological activity was noted. Alternate scheduling and routes of administration are now being explored.

Topics: Adult; Aged; Dose-Response Relationship, Drug; Drug Administration Schedule; Female; Follow-Up Studies; Humans; Incidence; Infusions, Intravenous; Male; Maximum Tolerated Dose; Middle Aged; Neoplasm Staging; Neoplasms; Oligosaccharides; Risk Assessment; Survival Analysis; Thrombocytopenia; Treatment Outcome