Phase II Evaluation of Docetaxel Plus Exisulind in Patients With Androgen Independent Prostate Carcinoma

OBJECTIVES

In this phase II study, the combination of docetaxel and exisulind (a GMP phosphodiesterase inhibitor) was given to patients with metastatic androgen independent prostate cancer (AIPC) to establish efficacy, assess toxicity, and determine pharmacokinetics of docetaxel administered alone and in combination with exisulind.

METHODS

Fourteen patients with metastatic AIPC were registered to receive weekly docetaxel for 4 weeks, followed by 2 weeks of rest; repeated up to a maximum of 6 cycles. Exisulind 250 mg was given orally twice a day starting on day 8 of the study and taken continuously.

RESULTS

All patients were evaluable for toxicity, response and survival. Grade 3 reversible toxicities included: fatigue, nausea, diarrhea, abdominal pain, rash, syncope, pulmonary edema, deep vein thrombosis, congestive heart failure, and elevations in transaminases, requiring therapy delays and/or dose reductions, or removal from therapy. Only 3 out of 14 patients (21.4%) had a 50% decline in prostate specific antigen (PSA) level that lasted > or =4 weeks; 1 out of 14 patients (7%) had a lymph node response. Median survival was 17.28 months. Docetaxel pharmacokinetics for 11 patients demonstrated mean +/- SD clearance values that were similar during week 1 and week 3 when exisulind had been added.

CONCLUSIONS

: Overall, our trial indicated that the toxicity profile and efficacy of this regimen is unlikely to be substantially better than single agent docetaxel.

A phase II evaluation of imatinib mesylate (G) in stage M0 prostate cancer (PC) patients (pts) on hormonal therapy (HT) with evidence of biochemical relapse

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Background: Imatinib mesylate (Gleevec, G) is a potent inhibitor of the tyrosine kinases and other signaling mediated events. Preclinical models suggest that G inhibits platelet derived growth factor (PDGF) and stem cell factor (SCF) which are important for prostate cancer growth. This trial was designed to evaluate the safety and efficacy of G in PCA pts on HT with stage M0 disease. Methods: Eligible PCA pts included: stage M0 disease with rising PSA levels while on hormonal therapy, no prior chemotherapy. Planned treatment included G 400 mg PO BID given up to a maximum of 12 months. The statistical endpoint for this trial was the% of pts with a ↓ in prostate specific antigen (PSA) ≥ 50% lasting ≥ 4 wks. A 2 stage trial was designed where the study would terminate if the% of pts meeting the endpoint was not convincingly > 30% with 5% chance for error. Pts with a > 50% rise in PSA from baseline were removed from study. Follow-up included monthly toxicities and PSA (specimens frozen/stored until completion of each 3 months of therapy). Results: From 10/1/02–10/11/04, nine pts were enrolled. Pt characteristics included median: age of 67 years (range 52–80), ECOG performance status of 0 (range 0–1), baseline PSA of 29.6 ng/ml (range 2.69–39.52), # prior hormonal manipulations of 3 (1–5). Prior local therapies included: 1 status post (s/p) RP alone, 2 s/p RT alone, 2 s/p neoadjuvant HT plus RP, 2 s/p neoadjuvant HT plus RT. Two pts had no prior local therapy. Two pts had prior salvage RT, 1 had prior palliative RT. Eight of 9 pts evaluable for response and toxicity. One patient never received treatment. None of the pts had a decline 50% decline in PSA level lasting ≥ 4 weeks. Three of 8 pts (38%) had rapid increases in PSA and 4/8 pts (50%) developed metastatic disease after 3 months of therapy. Only one pt completed 12 months of planned therapy. Grade 3/4 toxicities included: fatigue (25%), rash (25%), arthralgias (12.5%), peripheral edema (25%), depression (12.5%), necessitating dose delays and/or discontinuation of G in 4/8 pts (50%). Conclusions: These data suggest significant toxicity and low clinical benefit. Further evaluation of Gleevec in this pt population is not warranted.

No significant financial relationships to disclose.

A Phase I and Pharmacokinetic Study of Short Infusions of UCN-01 in Patients with Refractory Solid Tumors

Purpose: To define the maximum tolerated dose and the dose-limiting toxicity of the kinase modulator UCN-01 administered as a short (1-3 hours) infusion to patients with refractory solid tumors and to evaluate the pharmacokinetics of this novel agent.

Experimental Design: Twenty-four patients (15 men, 9 women; median age, 59 years; Eastern Cooperative Oncology Group Performance Status, 0-2) were treated with UCN-01 in this phase I study. Using an accelerated titration design, six dose levels were evaluated ranging from 3 mg/m2 over 3 hours to 95 mg/m2 over 1 to 3 hours administered every 28 days. Plasma, urine, and saliva samples were collected for pharmacokinetic analysis.

Results: Seventy courses were evaluable for toxicity. The most frequent adverse events were grade 1 to 2 nausea, vomiting, hyperglycemia, and hypotension. Hypotension was dose limiting at 95 mg/m2 when UCN-01 was administered over 1 hour. The recommended dose of UCN-01 as a short infusion is 95 mg/m2 over 3 hours for the first course and 47.5 mg/m2 over 3 hours for second and subsequent courses. No objective responses were observed. Mean (SD) pharmacokinetic variable values in nine patients treated at 95 mg/m2 over 3 hours were volume of distribution at steady state, 14 (5.4) L; β half-life, 406 (151) hours; systemic clearance, 0.028 (0.017) L/h; Cmax, 51 (16) μmol/L; and area under the curve, 19,732 (12,195) μmol/L h.

Conclusions: UCN-01 is well tolerated when given at doses of 95 mg/m2 over 3 hours every 28 days with second and subsequent courses given at 50 % of the first course dose.

A phase I and pharmacologic study of pyrazoloacridine and cisplatin in patients with advanced cancer

Pyrazoloacridine (PZA, NSC366140, PD115934) is an acridine derivative currently undergoing clinical evaluation. In preclinical testing, PZA has shown selectivity for solid tumor cell lines, activity in hypoxic, noncycling, and multidrug-resistant cell lines, and synergy with cisplatin in a variety of lung cancer cell lines. In early phase I clinical studies PZA has shown modest activity in ovarian, cervical, and colon cancer. The purpose of the present study was threefold: to determine the maximally tolerated doses of the combination of PZA (3-h infusion) and cisplatin administered with and without Filgrastim (G-CSF) (Amgen, Thousand Oaks, CA) every 3 weeks in untreated or minimally pretreated patients, to describe and quantify the clinical toxicities of combination chemotherapy with PZA and cisplatin, and to evaluate the effects of drug sequencing on the toxicity profile and pharmacologic behavior of PZA. The starting doses in this dose-escalation trial were PZA 400 mg/m2 as a 3-h intravenous infusion and cisplatin 50 mg/m2 as a 1 mg/min intravenous infusion. The sequence of drugs was alternated with each successive course in each patient treated. Twenty-one patients with refractory solid tumors received 43 courses of therapy through four dose levels. Neutropenia was dose-limiting and defined the maximum tolerated dose of PZA 400 mg/m2 and cisplatin 50 mg/m2 without G-CSF support. With G-CSF support, nausea and vomiting were dose-limiting. The maximum tolerated and recommended doses for further study of this combination are PZA 600 mg/m2 over 3 h and cisplatin 50 mg/m2 followed by G-CSF support. Pharmacokinetic analysis showed that sequence does not impact on the pharmacokinetics of PZA when given in combination with cisplatin.