Phase I study of a novel taxane BMS-188797 in adult patients with solid malignancies.

PURPOSE: Preclinical studies show that BMS-188797 has a broad spectrum of antitumor activity in in vitro cytotoxicity assays and tumor xenograft models. We did a phase I trial designed to determine the maximum tolerated dose and the pharmacokinetics of BMS-188797 when administered i.v. MATERIALS AND METHODS: BMS-188797 was administered i.v. over 60 minutes once every 21 days to 51 patients. The initial dose cohort of 3.75 mg/m(2) was set at approximately one third the lethal dose in dogs. Doses were subsequently escalated in cohorts according to a modified Fibonacci design. RESULTS: Fifty-one patients received a total of 160 cycles of therapy. The dose-limiting toxicity of febrile neutropenia occurred in two patients at the 200 mg/m(2) cohort. Moderate to severe sensory neuropathy occurred in 12 patients (24%). Four radiographic partial responses based on the Response Evaluation Criteria in Solid Tumors occurred: two in subjects with breast cancer, one in a subject with non-small cell lung cancer, and one in a subject with renal cell carcinoma. The duration of the partial responses observed were 24.1 months (renal cell carcinoma), 5.7 and 4.3 months (breast cancer), and 4.5 months (non-small cell lung cancer). Pharmacokinetics appear linear at doses through 110 mg/m(2) but not at higher doses. CONCLUSION: The dose-limiting toxicity in this single-agent study of BMS-188797 was febrile neutropenia. The recommended phase II dose of BMS-188797 as a single agent is 175 mg/m(2) i.v. for 1 hour administered every 3 weeks.

Randomized study of three different doses of suramin administered with a fixed dosing schedule in patients with advanced prostate cancer: results of intergroup 0159, cancer and leukemia group B 9480.

PURPOSE: To test the hypothesis that the efficacy and toxicity of suramin in the treatment of patients with hormone-refractory prostate cancer was dose dependent. PATIENTS AND METHODS: Patients were randomized with equal probability to receive low-, intermediate-, or high-dose suramin (total doses 3.192, 5.320, and 7.661 g/m(2), respectively). Overall survival, time to progression, and response rate (prostate-specific antigen [PSA] and objective) for each treatment arm were compared. Relationships between plasma suramin concentrations and response, toxicity, and survival were also evaluated. RESULTS: Three hundred ninety patients were randomized. For the low-, intermediate-, and high-dose arms, the median survival time was 16, 14, and 13 months, respectively (P =.49). The objective response rate was 9%, 7%, and 15%, respectively (P =.10). PSA response rates were 24%, 28%, and 34%, respectively (P =.082). Landmark analyses of a 50% decline in PSA at 20 weeks showed a significant correlation with survival. There was a dose-response relationship between dose and toxicity. After adjusting for treatment arm, the measured suramin concentration was not associated with clinical response, PSA response, survival, or toxicity. CONCLUSION: Although high-dose suramin was associated with higher objective and PSA response rates, these were not statistically significant. Overall, no dose-response relationship was observed for survival or progression-free survival, but toxicity was increased with the higher dose. Patients treated with the low-dose level experienced modest toxicity, making it the preferred arm on this study. The lack of a dose-response relationship and the toxicity profile observed raise questions regarding the utility of suramin, particularly high-dose suramin, as administered on this schedule.

Safety and efficacy of the MDR inhibitor Incel (biricodar, VX-710) in combination with mitoxantrone and prednisone in hormone-refractory prostate cancer.

PURPOSE: VX-710 (biricodar, Incel) restores drug sensitivity to cells expressing P-glycoprotein (P-gp) and multidrug resistance-associated protein (MRP1). MRP1 is expressed in a high proportion of prostate tumors while P-gp expression is variable. Since mitoxantrone (M) and prednisone (P) are substrates for MDR transporters, we initiated a study to evaluate the safety, pharmacokinetics, and efficacy of VX-710 plus M/P in patients with hormone-refractory prostate cancer (HRPC). PATIENTS AND METHODS: Eligible patients had progressive HRPC (defined as new lesions, new disease-related pain, or 50% increase in PSA within 6 weeks of entry), testosterone <30 ng/ml, no prior chemotherapy, ECOG performance status of 0-3, and adequate organ function. Patients received VX-710 (120 mg/m(2) per h) as a 72-h continuous intravenous infusion with intravenous bolus mitoxantrone (12 mg/m(2)) administered 4 h after VX-710 was started and prednisone (5 mg twice daily) administered throughout the study treatment. Endpoints included serum PSA response, PSA response duration, time to PSA progression, pain reduction, and quality of life measures. RESULTS: Enrolled in the study were 40 patients and 184 courses of VX-710 plus M/P were administered. Intensive pharmacokinetics, which were performed on six patients who received one cycle of M/P alone, followed by VX-710 plus M/P for all other cycles, showed that VX-710 did not alter mitoxantrone clearance. VX-710 blood concentration at the time of mitoxantrone administration averaged 4.52 microg/ml. VX-710 plus M/P was well tolerated. Transient nausea/vomiting and mild neutropenia were the principal treatment toxicities. Five patients experienced an uncomplicated febrile neutropenic episode (12%), three had severe nausea/vomiting, and two experienced transient moderate to severe ataxia. Of the 40 patients, 12 (30%, 95% confidence interval 16-44%) had a reduction in PSA of >/=50% and 9 of the 12 patients (23% overall, 95% CI 10-35%) achieved a reduction in PSA of >/=80% that was sustained for the duration of treatment with M/P plus VX-710. The median time to PSA progression was 41 weeks (95% CI 34-68 weeks). Of the 40 patients, 15 completed treatment with stable disease and 13 had progressive disease with increasing serum PSA during study treatment. Median survival was 48 weeks for the intent-to-treat population of 40 patients. CONCLUSIONS: The addition of VX-710 to M/P therapy did not appear to increase the proportion of patients with significant serum PSA reductions compared to M/P alone. However, the duration of PSA response observed for the 12 PSA responders suggests that MDR inhibition may benefit some patients with HRPC. In addition to MRP1 or P-gp expression, other mechanisms of drug resistance are probably associated with the relative insensitivity of HRPC to cytotoxic therapy.

Higher doses of mitoxantrone among men with hormone-refractory prostate carcinoma: a Cancer and Leukemia Group B study.

BACKGROUND: Mitoxantrone in combination with a low-dose glucocorticoid has been shown to produce more favorable outcomes among men with hormone-refractory prostate carcinoma than glucocorticoid alone. Therefore, the authors sought to determine the safety and activity of higher doses of mitoxantrone in combination with granulocyte-macrophage colony-stimulating factor (GM-CSF) and a glucocorticoid in preparation for a possible Phase III trial comparing standard to dose-escalated mitoxantrone. METHODS: This Phase II trial enrolled 45 patients from October 1996 to March 1998. Twenty-one patients without pelvic irradiation (Arm I) received 21 mg/m(2) of mitoxantrone every 3 weeks, and 24 patients who had received pelvic irradiation (Arm II) were given 17 mg/m(2) on the same schedule. All patients received 40 mg of hydrocortisone in divided doses daily and GM-CSF at 500 microg/daily for a minimum of 10 days per cycle beginning on the third day of the cycle. RESULTS: In Arm I, 33% of assessable patients achieved a partial response, 50% had a > or = 50% decline in their PSA, and 35% had a > or = 75% decline in PSA values. The comparable numbers in Arm II were 24%, 48%, and 35%, respectively. The median survival times were 12 months in Arm I and 14 months in Arm II. Treatment had to be discontinued in 13% of patients because of thrombocytopenia. No other significant toxicities were encountered. CONCLUSIONS: Higher doses of mitoxantrone (17 and 21 mg/m(2)) were associated with activity comparable to many estramustine combinations and generally were well tolerated. However, because the degree and frequency of thrombocytopenia were greater than that observed with standard dose mitoxantrone (12-14 mg/m(2)), and because the median survival is apparently comparable to standard dose mitoxantrone, this approach to HRPC cannot be recommended for Phase III testing.