Phase II multicenter trial of bevacizumab plus fluorouracil and leucovorin in patients with advanced refractory colorectal cancer: an NCI Treatment Referral Center Trial TRC-0301.

PURPOSE: To provide bevacizumab (BV) -based therapy to patients with advanced colorectal cancers (CRC) who had exhausted standard chemotherapy options, and to evaluate the response to BV combined with fluorouracil (FU) and leucovorin (LV) in this patient population. PATIENTS AND METHODS: This was a multicenter, single-arm treatment trial conducted under the National Cancer Institute Treatment Referral Center network nationwide. Patients were treated with BV 5 mg/kg every 2 weeks combined with FU/LV; FU was administered by bolus or continuous infusion. Eligibility criteria included advanced CRC that had progressed after irinotecan- and oxaliplatin-based chemotherapy, Eastern Cooperative Oncology Group performance status 0 to 2, and absence of thromboembolism. The primary end point was objective response rate (RR) in the first 100 assessable patients. All patients received follow-up for toxicity and survival. RESULTS: Due to rapid accrual, a total of 350 patients were enrolled at 32 participating sites nationwide by October 2003. In the initially planned cohort of 100 assessable patients, the objective RR was 4% (95% CI, 1.1% to 9.9%) by investigators' assessment and 1% (95% CI, 0% to 5.5%) based on independent review; median progression-free survival was 3.5 months and median overall survival was 9.0 months. The safety profile was similar to prior BV trials in CRC. Grade 3 to 4 hemorrhage occurred in 5% of patients, including 3.8% with bleeding in the GI tract. Other adverse events such as hypertension, thrombosis, and bowel perforation were also observed at rates consistent with other studies. CONCLUSION: For patients with advanced CRC that had progressed after both irinotecan-based and oxaliplatin-based chemotherapy regimens, the combination of BV and FU/LV was associated with rare objective responses.

Phase I and pharmacologic study of 17-(allylamino)-17-demethoxygeldanamycin in adult patients with solid tumors.

PURPOSE: To determine the clinical toxicities of 17-(allylamino)-17-demethoxygeldanamycin (17-AAG) given as a 1-hour infusion daily for 5 days every 3 weeks. PATIENTS AND METHODS: Nineteen patients received 17-AAG over six dose levels (10 to 56 mg/m(2)) using an accelerated titration scheme. Drug levels of 17-AAG were determined by high-performance liquid chromatography. Biologic effects of 17-AAG were monitored by changes in the content of target proteins by immunoblot analysis of lysates prepared from peripheral-blood mononuclear cells. RESULTS: Toxicity was acceptable at doses up to 28 mg/m(2). The cohort was expanded to three patients at 40 mg/m(2) because a second occurrence of grade 2 hepatic transaminitis occurred. Two of six assessable patients who received 56 mg/m(2) had reversible, grade 3 hepatic transaminitis. Five additional patients were enrolled at 40 mg/m(2); none had dose-limiting toxicity. The maximum plasma concentrations (C(max)) of 17-AAG at 40 and 56 mg/m(2) were 1,724 and 2,046 ng/mL, respectively; the average plasma exposures (AUC) were 2,809 and 6,708 hours.ng/mL, respectively. Less than 3% of the daily dose was excreted into the urine. Clearance did not correlate with body-surface area. Possible biologic activity was suggested by apparent increased protein content of either glucose-related 78 kd protein or heat shock protein 70 with >/= 14 mg/m(2) and decreased protein content of either Lck or Raf1 with >/= 28 mg/m(2) of 17-AAG. CONCLUSION: 17-AAG 40 mg/m(2) (median dose, 70 mg) was well tolerated when given daily for 5 days every 3 weeks.

Risks and benefits of phase 1 oncology trials, 1991 through 2002.

BACKGROUND: Previous reviews of phase 1 oncology trials reported a rate of response to treatment of 4 to 6 percent and a toxicity-related death rate of 0.5 percent. These results may not reflect the rates in current phase 1 oncology trials. METHODS: We reviewed all nonpediatric phase 1 oncology trials sponsored by the Cancer Therapy Evaluation Program at the National Cancer Institute between 1991 and 2002. We report the rates of response to treatment, of stable disease, of grade 4 toxic events, and of treatment-related deaths. RESULTS: We analyzed 460 trials involving 11,935 participants, all of whom were assessed for toxicity and 10,402 of whom were assessed for a response to therapy. The overall response rate (i.e., for both complete and partial responses) was 10.6 percent, with considerable variation among trials. "Classic" phase 1 trials of single investigational chemotherapeutic agents represented only 20 percent of the trials and had a response rate of 4.4 percent. Studies that included at least one anticancer agent approved by the Food and Drug Administration constituted 46.3 percent of the trials and had a response rate of 17.8. An additional 34.1 percent of participants had stable disease or a less-than-partial response. The overall rate of death due to toxic events was 0.49 percent. Of 3465 participants for whom data on patient-specific grade 4 toxic events were available, 14.3 percent had had at least one episode of grade 4 toxic events. CONCLUSIONS: Overall response rates among phase 1 oncology trials are higher than previously reported, although they have not changed for classic phase 1 trials, and toxicity-related death rates have remained stable. Rates of response and toxicity vary, however, among the various types of phase 1 oncology trials.

Role of body surface area in dosing of investigational anticancer agents in adults, 1991-2001.

The prescribed dose of anticancer agents is most commonly calculated using body surface area as the only independent variable, and it has been shown that this approach still results in large interpatient variability in drug exposure. Here, we retrospectively assessed the pharmacokinetics of 33 investigational agents tested in phase I trials from 1991 through 2001, as a function of body surface area in 1650 adult cancer patients. Twelve of the drugs were administered orally, 19 were administered intravenously, and two were administered by both routes. Body surface area-based dosing was statistically significantly associated with a reduction in interpatient variability in drug clearance for only five of the 33 agents: docosahexaenoic acid (DHA)-paclitaxel, 5-fluorouracil/eniluracil, paclitaxel, temozolomide, and troxacitabine. These results do not support the use of body surface area in dose calculations and suggest that alternate dosing strategies should be evaluated. We conclude that body surface area should not be used to determine starting doses of investigational agents in future phase I studies.

Impact of prolonged infusions of the putative differentiating agent sodium phenylbutyrate on myelodysplastic syndromes and acute myeloid leukemia.

The aromatic fatty acid sodium phenylbutyrate (PB) promotes cytostasis and differentiation in a wide variety of tumor types; among several molecular activities, inhibition of histone deacetylase (HDAC) may account for many of its pharmacodynamic effects. A Phase I study demonstrated promising preliminary evidence of clinical activity in acute myeloid leukemia and myelodysplastic syndrome; however, plasma concentrations achieved at the maximum tolerated dose were less than those targeted based on in vitro studies. Because prolonged exposure to suboptimal concentrations of PB in vitro led to pharmacodynamic changes similar to a more brief exposure to higher concentrations, a study of the feasibility of prolonged administration of sodium PB was performed. Selected patients with acute myeloid leukemia and myelodysplastic syndrome were treated with sodium PB as a continuous i.v. infusion via ambulatory infusion pump. Sequential cohorts were treated for 7 consecutive days out of 14 or with 21 consecutive days out of 28. Prolonged infusions were well tolerated; dose-limiting central nervous system toxicity developed in 1 of 23 patients treated. End-of-infusion plasma concentrations were maintained within a range sufficient to inhibit HDAC. Two patients on the 21/28 schedule developed hematological improvement. Prolonged infusions of PB are well tolerated making this an attractive platform for the clinical investigation of HDAC inhibition.

Phase II Trial of Paclitaxel in Patients with Advanced Colon Cancer Previously Untreated with Cytotoxic Chemotherapy: An Eastern Cooperative Oncology Group Trial (PA286).

Paclitaxel was administered as a 24-h continuous infusion at 250 mg/m(2) in this Phase II trial in patients with adenocarcinoma of the colon or rectum. Nineteen patients were evaluated for toxity and 15 were assessable for response. There were no complete or partial responses, and toxicity present was primarily neutropenia. This study found that paclitaxel as a single agent does not have activity in adenocarcinoma of the colon or rectum.