Background: The hematopoietic growth factor P-100 is a monocyte-colony stimulating factor purified from human urine and has been reported to reduce neutropenia following chemotherapy. In this study the effect and toxicity of P-100 was evaluated in 26 patients receiving intensive chemotherapy for SCLC.
Study design: Chemotherapy consisted of four 28 day cycles of carboplatin (C) 600 mg/m2 i.v. on day 1 of cycle 1 + 2 and 300 mg/m2 i.v. on day 1 of cycle 3 + 4 and etoposide (E) 120 mg/m2 i.v. on day 1-3 of each cycle. Patients were randomised to receive P-100 for ten days following chemotherapy during either the first or second cycle. 12 Patients received P-100 with the first and 12 with the second cycle. For each group cycles with P-100 were compared to cycles without P-100.
Results: P-100 was well tolerated but no significant differences between cycles with and without P-100 were seen in the administered chemotherapy dose, depth and duration of neutropenia, number of blood or platelet transfusions, WHO grade 3-4 infection or requirement for intravenous antibiotics. Of 24 evaluable patients 14 (58.3%) achieved CR and 4 (16.6%) PR. Patients achieving CR received radiotherapy. The median time to progression was 169 days (range 38-995+ days) and the median survival time was 305 days (range 42-1052+ days). Three patients are alive after 2 years (11.5%), 2 without relapse (7.7%). Alopecia, nausea and vomiting occurred in all patients but no treatment related deaths occurred.
Conclusion: In this study P-100 did not significantly influence the myelotoxicity associated with carboplatin-etoposide chemotherapy in the treatment of SCLC.