Phase II ECOG trial of atrasentan in advanced renal cell carcinoma

5102

Background: Atrasentan, an oral selective endothelin A receptor antagonist, demonstrated activity in patients with RCC included in Phase I studies. Based on these preliminary findings, a phase II study was undertaken in patients with measurable or nonmeasurable (bone only) metastatic RCC. Methods: Patients with locally recurrent or metastatic disease were stratified on disease status (measurable or bone only metastases) and prior immunotherapy. Eligible patients also had no prior chemotherapy, no more than 1 prior immunotherapy, and ECOG PS 0, 1, or 2. Prior nephrectomy was permitted. Patients received atrasentan 10 mg/day po until progression or unacceptable toxicity. Standard RECIST criteria were used to assess response. The primary endpoint was the progression-free rate at 6 months. Rates of 25% among patients treated with prior immunotherapy and 45% among patients with no prior immunotherapy were considered promising. A two-stage design was used for cohorts with no prior immunotherapy. Results: Between July 2003 and July 2005, 98 patients were registered. Four patients were ineligible and 1 withdrew before treatment. Median duration of treatment was 10 weeks (range, 2 to 107 weeks). Toxicities were mild, with 73% of patients reporting no Grade 3 or higher treatment- related adverse events. Grade 4 adverse events included neutropenia (n=3), dyspnea (n=2), thrombosis and supraventricular arrhythmia (n=1 each). Six-month progression-free rates (90% CI) were 14% (6 - 25%), 0% (0 - 39%), 12% (3 - 28%) and 17% (5 - 38%) respectively for patients with prior immunotherapy and measurable disease (n=44), prior immunotherapy and bone metastases only (n=6), no prior immunotherapy and measurable disease (n=25), and no prior immunotherapy and bone metastases only (n=18). Median progression-free survival was 2.3 months (95% CI, 2.0 - 3.5 months). Conclusions: While well-tolerated, atrasentan did not yield 6-month progression-free rates that would support its use as first-line monotherapy in patients with advanced RCC.

No significant financial relationships to disclose.

A phase II trial of docetaxel plus carboplatin in hormone refractory prostate cancer (HRPC) patients who have progressed after prior docetaxel chemotherapy: Preliminary results

14533

Background: Treatment options for HRPC patients who progress after docetaxel chemotherapy are limited. Carboplatin may enhance the efficacy of docetaxel chemotherapy. Methods: We prospectively treated HRPC patients with documented PSA or radiographic progression during a minimum of 2 cycles of docetaxel-based chemotherapy or within 45 days of completing therapy. No prior platinum was allowed, though patients may have received other prior chemotherapy. Patients received docetaxel 60 mg/m2 and carboplatin AUC (4) every 21 days until progression or unacceptable toxicity. Measurable response was assessed by RECIST criteria. PSA declines were assessed per PSA Working Group; 2 patients were not evaluable as they received only 1 cycle of therapy but are included in the denominator. Results: Interim data is available on the 1st stage of patients (n = 16) enrolled in this ongoing phase II trial. Median age was 69 years (range 46–81), 94% white. Baseline performance status was 0 or 1 in 88%. Prior therapies included antiandrogens (80%) and ketoconazole (47%); docetaxel was used alone (33%), with estramustine (33%) or another agent (33%). Median PSA at baseline was 44 ng/ml (range 4.9–4801). Patients received a median of 3 cycles of docetaxel/carboplatin (range 1–12+). PSA declines of ≥50% were noted in 3 of 16 patients (19%, 90% C.I. 5–42%). In addition, 5 patients had SD, suggesting clinical benefit in 50% (90% C.I. 28–72%). Of 10 patients with measurable disease at baseline, 2 (20%; 90% C.I. 4–51%) had confirmed PR. Therapy was well-tolerated, with no treatment-related deaths and five grade 3 toxicities, including anemia (1), leukopenia (3) and hyperglycemia (1). Median time to progression was 2.7 months (range 0–13.4); median survival was 11.7 months (95% C.I. 6.7–14.0). Conclusions: In preliminary analyses, docetaxel plus carboplatin demonstrated encouraging activity in patients who progressed after docetaxel-based therapy. PSA declines ≥50% were seen in 19%; measurable responses in 20%. Accrual is ongoing. Final analyses will include correlation of response to serum markers of neuroendocrine differentiation. (Supported by BMS).

No significant financial relationships to disclose.

Phase II study of low dose (LD) and high dose (HD) premarin in androgen independent prostate cancer (AIPC)

4560

Background: Estrogens, including DES, transdermal estradiol, estramustine and PC-SPES, have shown antitumor activity in AIPC. We tested two doses of Premarin to determine efficacy and safety of this commonly available estrogen. Methods: Patients with progressive AIPC were eligible. Prior estrogen use, significant cardiac or thromboembolic disease, and concurrent steroids were not allowed. Patients were randomized to Premarin 1.25 mg once (LD) or 3 times (HD) daily. Prophylactic breast irradiation was encouraged and warfarin 1 mg daily was required, unless contraindicated. After the first stage of accrual, the LD arm was closed because of limited activity, while the HD arm continued to the 2nd stage. Results: 46 patients were enrolled; 17 patients were randomized to LD Premarin, 29 patients assigned to HD Premarin by randomization or direct assignment. One patient withdrew consent prior to therapy. Median follow up is 5.3 months. Median age was 69 years (range 52–86) and median PSA 84.6 ng/ml (range 2.5–794.1). 19 patients (41%) had measurable disease. PSA declines ≥ 50% were seen in 0% (95% C.I., 0–19.5) and 32.1% (95% C.I., 15.9–52.4) of patients treated with LD and HD premarin. 1 patient treated with HD Premarin had a partial measurable response (8.3%; 95% C.I., 0.2–38.5). Median time to progression was 3.3 and 3.2 months in the LD and HD arms, respectively. Premarin was well tolerated in 45 evaluable patients. One grade 4 toxicity was noted, a stroke in the LD arm. Grade 3 toxicity was rare with 1 allergic reaction, 2 DVTs and 3 episodes of GI toxicity in one patient. Two patients experienced grade 3 elevations in PT requiring modification of warfarin dose. No significant gynecomastia was reported. Analysis of serially drawn hormone levels and molecular correlates of treatment response is pending. Conclusions: HD Premarin is associated with a 32.1% PSA response rate, while no responses were seen with LD Premarin. A measurable response was noted in 1 of 12 patients treated with HD Premarin. Toxicity was modest, though thromboembolism was seen even with prophylactic warfarin. Ongoing studies are evaluating molecular and clinical predictors of response.

No significant financial relationships to disclose.

Phase II trial of epothilone B analogue BMS-247550 in advanced carcinoma of the urothelium (E3800): A trial of the Eastern Cooperative Oncology Group

4543

Background: Patients (pts) with advanced urothelial carcinoma who progress following first line therapy have limited effective therapeutic options. The epothilones are a class of antineoplastics with a broad range of antitumor activity. We evaluated BMS-247550 in pts with advanced urothelial cancer having received 1 prior systemic therapy regimen. Methods: Pts with TCC or mixed histologies containing TCC received BMS-247550 40 mg/m2 IV over 3 hours on day 1 of a 3-week cycle. Dose modifications occured for low granulocytes and/or platelets, mucositis, sensory neuropathy, and other Grade 3 or 4 toxicities. Pts remained on treatment until disease progression or unacceptable toxicity. Standard ECOG response criteria were used. Results: Total accrual (allowing for ineligible pts) was 45 pts, of whom 17 had received prior taxanes. One pt was ineligible (2 prior regimens) and was excluded from this analysis. Sixteen pts are still being evaluated for eligibility. The pt cohort was 82% male and 86% Caucasian. The median age was 63 (range 37–81), 70%, 7% and 23% had 1, 2 and 3 MSKCC risk factors respectively. Eighty-two % of pts had distant metastatic disease at study entry. A median of 2 cycles were administered (range, 1–8). The most common reasons for discontinuing treatment were progressive disease (65%) and toxicity (25%). Twelve pts experienced grade 4 toxicity, including leukopenia (n = 5), neutropenia (n = 9), ventricular arrhythmia, hypotension, DIC, stomatitis, elevated bilirubin, dyspnea, febrile neutropenia, hypoxia, acidosis, and elevated creatinine (n = 1 patient each). One pt died of cardiac failure following numerous grade 4 toxicities, including neutropenic infection. Two other deaths due to progressive disease occurred while pts were receiving treatment. Response information is available for 37 of 44 potentially eligible pts. There have been 5 partial responses, 3 among pts who had previously received taxanes, 17 pts had stable disease for at least 6 weeks. Conclusions: BMS-247550 has modest activity in pts with previously treated advanced TCC of the urothelium, but at the cost of modest-significant toxicity. Activity in pts previously treated with paclitaxel is of interest, however its ultimate utility remains undefined.

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Ecteinascidin-743 (ET-743) for chemotherapy-naive patients with advanced soft tissue sarcomas: multicenter phase II and pharmacokinetic study

PURPOSE

To evaluate the response rate, toxicity profile, and pharmacokinetics of ecteinascidin-743 (ET-743) as first-line therapy in patients with unresectable advanced soft tissue sarcoma (STS).

PATIENTS AND METHODS

Thirty-six patients with STS were enrolled onto the study between September 1999 and August 2000. Patients were treated with 1.5 mg/m2 of ET-743 given as a 24-hour continuous intravenous (IV) infusion every 21 days. Pharmacokinetic sampling was performed in 23 patients.

RESULTS

One complete and five partial responses were achieved in 35 assessable patients for an overall response rate of 17.1% (95% CI, 6.6% to 33.6%). In addition, one patient had a minor response, leading to an overall clinical benefit of 20%. Neutropenia and transaminitis were the main grade 3 to 4 toxicities, which occurred in 33% and 36% of the patients. The estimated 1-year progression-free and overall survival rates were 21% (95% CI, 11% to 41%) and 72% (95% CI, 59% to 88%), respectively. Total body clearance (L/h) was not significantly correlated with body-surface area (r = -0.28; P = .21). Mild hepatic impairment or the extent of prior cytotoxic therapy does not seem to contribute significantly to the high interpatient variability (49%) in the clearance of this drug. Severity of treatment-related toxicity was not correlated with pharmacokinetic variables.

CONCLUSION

ET-743 demonstrates clinical activity as first-line therapy against STS with acceptable toxicity. Additional studies to establish empirical dosing guidelines may be necessary to improve the safety of the drug in patients with varying degrees of hepatic dysfunction and definitively establish the role of ET-743 for patients with these malignancies.

Finasteride and bicalutamide as primary hormonal therapy in patients with advanced adenocarcinoma of the prostate

BACKGROUND

Medical or surgical castration is effective in advanced prostate cancer but with profound side-effects, particularly on sexual function. Effective, less toxic therapies are needed. This study examined whether the addition of finasteride to high-dose bicalutamide enhanced disease control, as measured by additional decreases in serum prostate-specific antigen (PSA).

PATIENTS AND METHODS

Forty-one patients with advanced prostate cancer received bicalutamide (150 mg/day). Finasteride (5 mg/day) was added at first PSA nadir. Serum PSA was measured every 2 weeks until disease progression. Questionnaires were administered to assess sexual function.

RESULTS

Median follow-up is 3.9 years. At the first PSA nadir, median decrease in PSA from baseline was 96.5%. Thirty of 41 patients (73%) achieved a second PSA nadir and median decrease of 98.5% from baseline. Median time to each nadir was 3.7 and 5.8 weeks, respectively. Median time to treatment failure was 21.3 months. Toxicities were minor, including gynecomastia. Seventeen of 29 (59%) and 12 of 24 (50%) men had normal sex drive at baseline and at second PSA nadir, respectively. One-third of men had spontaneous erection at both time points.

CONCLUSION

Finasteride provides additional intracellular androgen blockade when added to bicalutamide. Duration of control is comparable to castration, with preserved sexual function in some patients.

Phase II and pharmacokinetic study of ecteinascidin 743 in patients with progressive sarcomas of soft tissues refractory to chemotherapy

PURPOSE

To assess the efficacy of the marine-derived alkaloid ecteinascidin 743 (ET-743) in patients with soft tissue sarcomas that progressed despite prior conventional chemotherapy and to characterize the pharmacokinetic profiles of ET-743 in this patient population.

PATIENTS AND METHODS

Thirty-six previously treated soft tissue sarcoma patients from three institutions received ET-743 as a 24-hour continuous intravenous (IV) infusion at a dose of 1,500 microg/m(2) every 3 weeks. Pharmacokinetic studies were also performed. Patients were restaged every two cycles for response by objective criteria.

RESULTS

Objective responses were observed in three patients, with one complete response and two partial responses, for an overall response rate of 8% (95% CI, 2% to 23%). Responses were durable for up to 20 months. Two minor responses (43% and 47% tumor reduction) were observed, for an overall clinical benefit rate of 14%. The predominant toxicities were neutropenia and self-limited transaminitis of grade 3 to 4 severity in 34% and 26% of patients, respectively. The estimated 1-year time to progression and overall survival rates were 9% (95% CI, 3% to 27%) and 53% (95% CI, 39% to 73%), respectively. The maximum observed plasma concentration and total plasma clearance of ET-743 (mean +/- standard deviation), 1.04 +/- 0.48 ng/mL and 35.6 +/- 16.2 L/h/m(2), respectively, were consistent with previously reported values from phase I studies of the drug given as a 24-hour IV infusion.

CONCLUSION

ET-743 is a promising new option for the management of several histologic subtypes of sarcoma. Durable objective responses were obtained in a subset of sarcoma patients with disease progression despite prior chemotherapy. Additionally, the relatively high survival rate noted in this series of previously treated patients further justifies development of this agent.

A practical method to achieve prostate gland immobilization and target verification for daily treatment

PURPOSE

A practical method to achieve prostate immobilization and daily target localization for external beam radiation treatment is described.

METHODS AND MATERIALS

Ten patients who underwent prostate brachytherapy using permanent radioactive source placement were selected for study. To quantify prostate motion both with and without the presence of a specially designed inflatable intrarectal balloon, the computerized tomography-based coordinates of all intraprostatic radioactive sources were compared over 3 consecutive measurements at 1-min intervals.

RESULTS

The placement and inflation of the intrarectal balloon were well tolerated by all patients. The mean (range) displacement of the prostate gland when the intrarectal balloon was present vs. absent was 1.3 (0-2.2) mm vs. 1.8 (0-9.1) mm (p = 0.03) at 2 min respectively. The maximum displacement in any direction (anterior-posterior, superior-inferior, or right-left) when the intrarectal balloon was inflated vs. absent was reduced to < or =1 mm from 4 mm.

CONCLUSIONS

Both prostate gland immobilization and target verification are possible using a specially designed inflatable intrarectal balloon. Using this device, the posterior margin necessary on the lateral fields to ensure dosimetric coverage of the entire prostate gland could be safely reduced to 5 mm and treatment could be set up and verified using a lateral portal image.

Ovarian failure after adjuvant chemotherapy is associated with rapid bone loss in women with early-stage breast cancer

PURPOSE

We sought to evaluate the effects of chemotherapy-induced ovarian failure on bone loss and markers of skeletal turnover in a prospective longitudinal study of young women with breast cancer receiving adjuvant chemotherapy.

PATIENTS AND METHODS

Forty-nine premenopausal women with stage I/II breast cancers receiving adjuvant chemotherapy were evaluated within 4 weeks of starting chemotherapy (baseline), and 6 and 12 months after starting chemotherapy with dual-energy absorptiometry and markers of skeletal turnover osteocalcin and bone-specific alkaline phosphatase. Chemotherapy-induced ovarian failure was defined as a negative pregnancy test, greater than 3 months of amenorrhea, and a follicle-stimulating hormone > or = 30 MIU/mL at the 12-month evaluation.

RESULTS

Among the 35 women who were defined as having ovarian failure, highly significant bone loss was observed in the lumbar spine by 6 months and increased further at 12 months. The median percentage decrease of bone mineral density in the spine from 0 to 6 months and 6 to 12 months was -4.0 (range, -10.4 to +1.0; P =.0001) and -3.7 (range, -10.1 to 9.2; P =.0001), respectively. In contrast, there were no significant decreases in bone mineral density in the 14 patients who retained ovarian function. Serum osteocalcin and bone specific alkaline phosphatase, markers of skeletal turnover, increased significantly in the women who developed ovarian failure.

CONCLUSION

Chemotherapy-induced ovarian failure causes rapid and highly significant bone loss in the spine. This may have implications for long-term breast cancer survivors who may be at higher risk for osteopenia, and subsequently osteoporosis. Women with breast cancer who develop chemotherapy-induced ovarian failure should have their bone density monitored and treatments to attenuate bone loss should be evaluated.