Quality of life impact of three different doses of suramin in patients with metastatic hormone-refractory prostate carcinoma: results of Intergroup O159/Cancer and Leukemia Group B 9480.

BACKGROUND: Research has suggested that men with hormone-refractory prostate carcinoma have a lower quality of life (QOL) compared with men who have hormone-sensitive prostate carcinoma and that quality of life (QOL) steadily declines over the last year of life for men with prostate carcinoma. The primary purpose of the current study was to evaluate whether there was evidence of palliative effects associated with suramin at any of the three doses administered in the original clinical trial. METHODS: Patients with histologically confirmed advanced hormone-refractory adenocarcinoma of the prostate were randomized to receive suramin at a low dose (n = 129; median age, 69 years), an intermediate dose (n = 129; median age, 71 years), or a high dose (n = 127; median age, 70 years) as part of the Intergroup 0159/Cancer and Leukemia Group B 9480 trial. Patients completed a battery of assessment tools, including the Functional Assessment of Cancer Therapy (FACT)-Prostate, the Center for Epidemiological Studies-Depression Scale (CES-D), the Brief Pain Inventory, and an opioid medication log, at baseline, on Day 1 of the sixth week of active therapy, during the second week after treatment termination, and 3 months after administration of the final suramin dose. RESULTS: Patients who received low-dose suramin reported improvement in QOL (FACT-General: P < 0.01; FACT-Treatment Outcome Index: P < 0.01) and decreased levels of depression (CES-D: P < 0.0006) during treatment compared with patients in the intermediate- and high-dose arms. After treatment, all groups experienced equal decreases in FACT and CES-D scores. CONCLUSIONS: The pattern of results suggests that the lowest dose of suramin administered had a palliative effect in terms of improvement in QOL and decreased levels of depression and that this effect was lost once suramin was discontinued.

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.