Phase II trial of flavopiridol, a cyclin dependent kinase inhibitor, in untreated metastatic malignant melanoma

PURPOSE: To test the activity of the cyclin dependent kinase (cdk) inhibitor flavopiridol in malignant melanoma, a disease with frequent abnormalities of the cyclin dependent kinase system. PATIENTS AND METHODS: Patients had histologically proven, unidimensionally measurable malignant melanoma, incurable by standard therapy. Prior adjuvant immunotherapy was allowed, but patients were otherwise untreated for advanced disease. Flavopiridol was administered at a dose of 50 mg/m(2) IV over 1 hour daily x 3 days every 3 weeks. Patients were assessed for response every 2 cycles. RESULTS: 17 patients were accrued over 5 months. No objective responses were documented in the 16 patients evaluable for response. Seven patients (44%) had stable disease after 2 cycles, with a median of 2.8 months (range 1.8-9.2). The most common treatment-related non-hematologic toxicities were diarrhea (82%), nausea (47%), fatigue (41%), anorexia (35%) and vomiting (29%). Most treatment-related toxicities were mild, except for diarrhea (grade 3 in 3 patients, grade 4 in 1 patient), nausea (grade 3 in 1 patient) and tumor pain (grade 3 in 1 patient). Hematologic toxicities were minimal, none worse than grade 2. Eighty-eight percent of patients received >/=90% planned dose intensity; 2 patients had dose reductions for gastrointestinal (GI) toxicity. CONCLUSIONS: Flavopiridol is well tolerated at the dose regimen used in this study, with an acceptable (primarily GI) toxicity profile. Although 7 of the 16 patients had stable disease ranging from 1.8 to 9.2 months in duration, there was no evidence of significant clinical activity in malignant melanoma by objective response criteria.     

The clinical development of new mitotic inhibitors that stabilize the microtubule

Microtubule-stabilizing agents are increasingly studied for cancer treatment based largely on the prior success of paclitaxel and docetaxel. In this review, we focus on the clinical development of epothilones and discodermolide, and we discuss salient preclinical and clinical highlights of these two novel natural products. These agents are distinguished by their biochemical features making them poor P-glycoprotein substrates and capable of inducing cytotoxicity in cell lines or in vivo tumor models harboring mutations in tubulin. There is now considerable data regarding the efficacy of the epothilones in human beings and discodermolide holds such promise, as well.     

Docetaxel,cisplatin, and 5-fluorouracil-based induction chemotherapy in patients with locally advanced squamous cell carcinoma of the head and neck: the Dana Farber Cancer Institute experience

BACKGROUND: The authors conducted a series of four Phase I-II trials of high-dose and intermediate-dose docetaxel, cisplatin, and 5-fluorouracil (TPF)-based induction chemotherapy for patients with advanced squamous cell carcinoma of the head and neck (SCCHN). The chemotherapy regimens and response rates for each trial were published previously. In the current analysis, the authors report the data on long-term survival, patterns of failure, and morbidity among the patients who were treated at their institution. METHODS: A total of 101 patients with previously untreated, locally advanced, curable SCCHN were entered onto the studies. Overall, 68 patients (67%) had N2-N3 disease, and 86 patients (85%) had Stage IV disease. Patients were treated with combinations of TPF with or without leucovorin. Cycles were repeated every 21-28 days for a total of 3 cycles followed by hyperfractionated radiotherapy. RESULTS: After a median follow-up of 49 months, 65 patients (64%) remain alive with no evidence of disease (NED), and 3 patients remain alive with disease, for an overall survival rate of 67% (68 patients). Twenty-six patients had locoregional recurrences (LRR), and 5 patients had both LRR and distant metastasis (DM). Only five patients had DM as the sole site of failure. Four patients underwent salvage surgery at the primary site and remain alive with NED. Excluding 17 patients with nasopharyngeal carcinoma, of 84 patients, 55 patients remain alive with NED (65%). Notably, 43 of 84 patients (51%) had oropharyngeal primary tumors, and 30 of those patients remain alive with NED (70%). Significant morbidity was low, with two treatment-related deaths. All but two of the surviving patients are able to swallow and had their feeding tubes removed. CONCLUSIONS: These data suggest that docetaxel adds incrementally to the efficacy of cisplatin and fluorouracil. Local-regional failures continue to be the major impediment to cure in these patients. Given the increase in local-regional dose intensity with chemoradiation, sequential treatment plans that integrate induction chemotherapy and chemoradiotherapy seem to be the logical next step.     

Flavopiridol administered using a pharmacologically derived schedule is associated with marked clinical efficacy in refractory, genetically high-risk chronic lymphocytic leukemia

Despite promising preclinical studies with the cyclin-dependent kinase inhibitor flavopiridol in chronic lymphocytic leukemia (CLL) and other diseases, previous clinical trials with this agent have been disappointing. The discovery of differential protein binding of flavopiridol in human and bovine serum contributed to an effective pharmacokinetic-derived schedule of administration of this agent. On the basis of pharmacokinetic modeling using our in vitro results and data from a previous trial, we initiated a phase 1 study using a 30-minute loading dose followed by 4 hours of infusion administered weekly for 4 of 6 weeks in patients with refractory CLL. A group of 42 patients were enrolled on 3 cohorts (cohort 1, 30 mg/m2 loading dose followed by 30 mg/m2 4-hour infusion; cohort 2, 40 mg/m2 loading dose followed by 40 mg/m2 4-hour infusion; and cohort 3, cohort 1 dose for treatments 1 to 4, then a 30 mg/m2 loading dose followed by a 50 mg/m2 4-hour infusion). The dose-limiting toxicity using this novel schedule was hyperacute tumor lysis syndrome. Aggressive prophylaxis and exclusion of patients with leukocyte counts greater than 200x10(9)/L have made this drug safe to administer at the cohort 3 dose. Of the 42 patients treated, 19 (45%) achieved a partial response with a median response duration that exceeds 12 months. Responses were noted in patients with genetically high-risk disease, including 5 (42%) of 12 patients with del(17p13.1) and 13 (72%) of 18 patients with del(11q22.3). Flavopiridol administered using this novel schedule has significant clinical activity in refractory CLL. Patients with bulky disease and high-risk genetic features have achieved durable responses, thereby justifying further study of flavopiridol in CLL and other diseases.     

A phase II study of ixabepilone (BMS-247550) in metastatic renal-cell carcinoma

INTRODUCTION: Ixabepilone (BMS-247550) is a semi-synthetic analog of epothilone B that has been characterized as a microtubule stabilizing agent with a mechanism of action distinct from taxanes. Suggestion of activity in renal cell carcinoma (RCC) has been seen in early clinical studies. METHODS: Eligible patients had metastatic RCC as well as ECOG performance status 0-2 and normal organ function. Patients received ixabepilone at a dose of 40 mg/m2 intravenously over three hours every 21 days. There was no restriction on RCC histology or prior treatment type, but prior treatment with tubule inhibitors was not allowed. The primary endpoint was RECIST defined response and radiographic evaluations were performed every three cycles. Toxicity evaluations utilized CTCAE v3.0 and were performed every cycle. Using a Simon two-stage optimal design with alpha = 0.1, beta = 0.1, a null hypothesized response rate of 0.05 and an alternative response rate of 0.2, an initial 12 patients were to be accrued with full accrual of 37 patients if at least one response were observed. RESULTS: A median of five cycles were administered. No objective responses were observed in the first 12 evaluable patients, and six patients showed stable disease for more than 18 weeks on therapy. Median time to progression among those with objective progression was nine weeks. One patient experienced grade 4 anemia and lymphopenia. Grade 3 adverse events included lymphopenia, neutropenia, leukopenia, diarrhea, and infection. Common grade 2 toxicities included alopecia, fatigue and anemia. CONCLUSION: Ixabepilone administered at a dose of 40 mg/m2 every 21 days should not be advanced for further study in metastatic RCC. Given previous results, however, other dosing schedules may be worthy of further investigation.