Allen S. Melemed

Gemcitabine Plus Paclitaxel Versus Paclitaxel Monotherapy in Patients With Metastatic Breast Cancer and Prior Anthracycline Treatment

PURPOSE The objective of this phase III global study was to compare the efficacy of gemcitabine plus paclitaxel (GT) versus paclitaxel in patients with advanced breast cancer. It was designed as a pivotal study for the approval of G for a breast cancer treatment indication. PATIENTS AND METHODS Patients who relapsed after adjuvant anthracyclines were randomly assigned to gemcitabine,1,250 mg/m(2) days 1 and 8 plus paclitaxel, 175 mg/m(2) on day 1; or, to paclitaxel at same dose on day 1 (both arms administered every 21 days, unblinded). The primary end point was overall survival (OS) and secondary end points were time to progression (TTP), response rate (RR), progression-free survival, response duration, and toxicity. This final OS analysis was planned at 380 deaths. RESULTS A total of 266 patients were randomly assigned to GT and 263 to paclitaxel. Median survival on GT was 18.6 months versus 15.8 months on paclitaxel (log-rank P = . 0489), with an adjusted Cox hazard ratio of 0.78 (95% CI, 0.64 to 0.96; P = .0187). The TTP was longer (6.14 v 3.98 months; log-rank P = .0002) and the RR was better (41.4% v 26.2%; P = .0002) on GT. There was more grade 3 to 4 neutropenia on GT and grade 2 to 4 fatigue and neuropathy were slightly more prevalent on GT. CONCLUSION This phase III study documents a role for gemcitabine in advanced breast cancer after anthracycline-based adjuvant therapy. The results establish GT as a reasonable choice for women who require cytoreduction with manageable toxicities and validate ongoing testing of GT in the adjuvant setting.

A phase II trial of arzoxifene, a selective estrogen response modulator, in patients with recurrent or advanced endometrial cancer.

OBJECTIVES The goal of this study was to determine response rate and evaluate toxicity of LY353381 (arzoxifene) in patients with recurrent or advanced endometrial cancer (EC). METHODS A phase II, open-labeled study with arzoxifene was performed at 13 centers. Patients with measurable recurrent/advanced EC not amenable to curative therapies were eligible if either the primary tumor or recurrent tumor was ER+ and/or PR+. If receptor status could not be determined, patients with well or moderately well-differentiated EC were also permitted. Prior use of salvage chemotherapy was not allowed; however, prior use of progestagens was permitted and patients were stratified by prior exposure to progestagen. Patients received 20 mg/day PO, and were treated for at least 8 weeks in the absence of disease progression or unacceptable toxicity. Efficacy was based on the frequency of complete (CR) and partial (PR) responses, and a 95% confidence interval (CI) was calculated. The Kaplan-Meier method was used to analyze time to progression and duration of response. RESULTS From February 1999 through April 2001, 37 patients were entered of whom 34 received treatment. Efficacy was evaluated for the 29 patients who received at least 4 weeks of therapy and at least one tumor response assessment. Safety was assessed in all 34 patients who received any drug. Thirty patients were defined as progestagen sensitive, and 4 patients were defined as progestagen failures. Twenty-six patients were ER+, and 22 were PR+. Nine (1 CR + 8 PR) of 29 patients responded (31%, CI 25-51%), with a median duration of response of 13.9 months. All 9 responses occurred in progestagen-sensitive patients. Two additional patients (one from each progestagen cohort) had stable disease for >or=6 months. The median progression-free interval was 3.7 months (CI 1.9-6.6 months) for all 29 patients. Toxicity was minimal with no grade 3-4 toxic effects, and 9 patients had only grade 1-2 toxic effects (7 grade 1, 2 grade 2). Hot flashes were the most common toxic effect and, in all 3 reported cases, were grade 1. CONCLUSIONS Arzoxifene has demonstrated a high response rate with the longest median duration of response reported in a phase II trial of this patient population. The ease of administration and extremely favorable toxicity profile make this an agent warranting further evaluation.

Phase I Study of a Third-Generation Selective Estrogen Receptor Modulator, LY353381.HCl, in Metastatic Breast Cancer

PURPOSE We conducted this phase I trial to determine the safety and toxicity profile of LY353381.HCl-a novel, potent, third-generation selective estrogen receptor modulator (SERM)-because this benzothiophene derivative demonstrated an SERM profile in preclinical studies. PATIENTS AND METHODS We studied 32 patients with recurrent or metastatic breast cancer. Patients were treated in four cohorts with oral daily doses of 10, 20, 50, and 100 mg. Pharmacokinetic sampling was performed during the first 72 hours following the first dose on day 1 and during the 24 hours after the day 57 dose. Eligibility criteria included Eastern Cooperative Oncology Group performance status of 0 to 2; no significant major organ dysfunction; and at least 3 weeks elapsed since most recent hormonal therapy, chemotherapy, and estrogen replacement therapy. RESULTS The median patient age was 56 years (range, 30 years to 76 years). The median number of prior chemotherapies for metastatic disease was one (range, zero to four), while the median number of prior hormone regimens for metastatic disease was two (range, zero to five). Receptor status was estrogen receptor (ER) positive and progesterone receptor (PR) positive, 19 patients; ER positive and PR negative, eight patients; ER positive and PR unknown, two patients; and ER and PR unknown, three patients. Dose-limiting toxicity was not observed. Treatment was well tolerated with mild to moderate hot flashes in 18 of 32 patients (56%) at all dose levels. Transvaginal ultrasound performed at baseline and after 12 weeks of treatment showed no endometrial thickening. Of the 32 patients evaluable for response, six patients had stable disease for at least 6 months with a median duration of 7.7 months (range, 6.2 months to 33.8 months). The pharmacokinetics of LY353381.HCl were generally linear with respect to time and studied dose range. CONCLUSION As predicted in preclinical testing, daily oral LY353381.HCl is safe, is well tolerated at all tested dose levels, and may be clinically beneficial in patients with extensively pretreated metastatic breast cancer. Further studies with LY353381 to evaluate the efficacy in patients with or without prior exposure to tamoxifen and fewer overall prior regimens are under way.

Phase II, Randomized, Double-Blind Study of Two Dose Levels of Arzoxifene in Patients With Locally Advanced or Metastatic Breast Cancer

PURPOSE To select a daily dose of arzoxifene (LY353381), a selective estrogen receptor modulator, for use in future studies in women with locally advanced or metastatic breast cancer who are either potentially tamoxifen sensitive (TS) or tamoxifen refractory (TR). PATIENTS AND METHODS This trial was a randomized, double-blind, phase II study of arzoxifene 20 mg (n = 55) and 50 mg (n = 57) in women with advanced or metastatic breast cancer. Patients were randomly assigned to balance for number of metastatic disease sites, prior tamoxifen therapy, and estrogen receptor status. The primary end point was tumor response rate (RR). Secondary end points included clinical benefit rate (CBR), time to progression (TTP), and toxicity. RESULTS Forty-nine patients were TS and 63 were TR. According to independent review, among TS patients, RR was higher in the 20-mg arm than the 50-mg arm (26.1% v 8.0%), with a longer TTP (8.3 v 3.2 months; P >.05). Among the TR patients, response rate was the same in the 20-mg and 50-mg arms (10.3%) with similar TTP (2.7 and 2.8 months, respectively; P >.05). CBR was higher in the 20-mg arm than in the 50-mg arm among TS patients (39.1% v 20.0%) and TR patients (13.8% v 10.3%). Arzoxifene was well tolerated. Dose-dependent toxicity was not demonstrated. There were no deaths during study. CONCLUSION Arzoxifene is effective in the treatment of TS and TR patients with advanced or metastatic breast cancer at the 20-mg and 50-mg dose levels. Toxicities are minimal, and the therapy is tolerated. The 20-mg dose seems to be at least as effective as the 50-mg dose. Accordingly, arzoxifene 20 mg/d was selected for further study in patients with breast cancer.

A randomized, double-blind, phase II study of two doses of pemetrexed as first-line chemotherapy for advanced breast cancer

Purpose: Pemetrexed has shown varied response rates in advanced breast cancer. This randomized, double-blind, phase II study was conducted to assess the efficacy and safety of two doses of pemetrexed in a homogeneous population. A secondary objective was to identify molecular biomarkers correlating with response and toxicity. Experimental Design: Patients with newly diagnosed metastatic breast cancer or locally recurrent breast cancer received 600 mg/m2 (P600 arm) or 900 mg/m2 (P900 arm) of pemetrexed on day 1 of a 21-day cycle. All patients received folic acid and vitamin B12 supplementation. Results: The P600 (47 patients) and P900 (45 patients) arms had response rates of 17.0% (95% confidence interval, 7.7-30.8%) and 15.6% (95% confidence interval, 6.5-29.5%) with ∼50% stable disease per arm, median progression-free survival of 4.2 and 4.1 months, and median times to tumor progression of 4.2 and 4.6 months, respectively. Both arms exhibited minimal toxicity (grade 3/4 neutropenia <20%, leukopenia <9%, and other toxicities <5%). Tumor samples from 49 patients were assessed for the expression levels of 12 pemetrexed-related genes. Folylpolyglutamate synthetase and thymidine phosphorylase correlated with efficacy. Best response rates and median time to tumor progression for high versus low thymidine phosphorylase expression were 27.6% versus 6.3% (P = 0.023) and 5.4 versus 1.9 months (P = 0.076), and for folylpolyglutamate synthetase were 37.5% versus 10.0% (P = 0.115) and 8.6 versus 3.0 months (P = 0.019), respectively. γ-Glutamyl hydrolase expression correlated with grade 3/4 toxicities: 78.6% for high versus 27.3% for low γ-glutamyl hydrolase (P = 0.024). Conclusion: The two pemetrexed doses yielded similar efficacy and safety profiles. Exploratory biomarker analysis identified efficacy and toxicity correlations and warrants further evaluation.

Phase I Trial and Pharmacokinetic Study of Pemetrexed in Children With Refractory Solid Tumors: The Children's Oncology Group

PURPOSE We report results of a phase I trial and pharmacokinetic study of pemetrexed (LY231514) in children and adolescents with refractory solid tumors. Pemetrexed is a novel antifolate that inhibits multiple enzymes necessary for the biosynthesis of thymidine and purine nucleotides. The purpose of this study was to determine the maximum-tolerated dose (MTD), dose-limiting toxicities (DLTs), and pharmacokinetic properties of pemetrexed in children. PATIENTS AND METHODS Pemetrexed was administered as a 10-minute intravenous infusion every 21 days. Patients received vitamin B12 and folic acid supplementation as well as dexamethasone prophylaxis. Cohorts of three to six children were enrolled at dose levels of 400, 520, 670, 870, 1,130, 1,470, 1,910, and 2,480 mg/m2. Pharmacokinetic studies were performed during the first course of treatment. RESULTS Thirty-three patients (31 assessable) with a median age of 12 years were enrolled. DLT occurred in one of six patients at 1,470 mg/m2 and two of four patients at 2,480 mg/m2. The MTD was 1,910 mg/m2. The primary DLTs were neutropenia and rash. No objective antitumor responses were seen. Mean plasma clearance, half-life, and steady-state volume of distribution values were 2.3 L/h/m2, 2.5 hours, and 5.4 L/m2, respectively. CONCLUSION Pemetrexed is well-tolerated in children with refractory solid tumors at doses similar to the MTD in adults. The recommended dose for phase II studies is 1,910 mg/m2 administered every 21 days with dexamethasone, folic acid, and vitamin B12 supplementation.

Phase 2 trial of pemetrexed in children and adolescents with refractory solid tumors: a Children's Oncology Group study.

Pemetrexed is a multi‐targeted antifolate that inhibits key enzymes involved in nucleotide biosynthesis. We performed a phase 2 trial of pemetrexed in children with refractory or recurrent solid tumors, including CNS tumors, to estimate the response rate and further define its toxicity profile.

Optimizing Collection of Adverse Event Data in Cancer Clinical Trials Supporting Supplemental Indications

PURPOSE Although much is known about the safety of an anticancer agent at the time of initial marketing approval, sponsors customarily collect comprehensive safety data for studies that support supplemental indications. This adds significant cost and complexity to the study but may not provide useful new information. The main purpose of this analysis was to assess the amount of safety and concomitant medication data collected to determine a more optimal approach in the collection of these data when used in support of supplemental applications. METHODS Following a prospectively developed statistical analysis plan, we reanalyzed safety data from eight previously completed prospective randomized trials. RESULTS A total of 107,884 adverse events and 136,608 concomitant medication records were reviewed for the analysis. Of these, four grade 1 to 2 and nine grade 3 and higher events were identified as drug effects that were not included in the previously established safety profiles and could potentially have been missed using subsampling. These events were frequently detected in subsamples of 400 patients or larger. Furthermore, none of the concomitant medication records contributed to labeling changes for the supplemental indications. CONCLUSION Our study found that applying the optimized methodologic approach, described herein, has a high probability of detecting new drug safety signals. Focusing data collection on signals that cause physicians to modify or discontinue treatment ensures that safety issues of the highest concern for patients and regulators are captured and has significant potential to relieve strain on the clinical trials system.

A Phase I Study of Pemetrexed (ALIMTA) and Cyclophosphamide in Patients with Locally Advanced or Metastatic Breast Cancer

Purpose: Determine the maximum tolerated dose (MTD) of pemetrexed and cyclophosphamide combination therapy for patients with locally advanced or metastatic breast cancer. Experimental Design: Patients with locally advanced or metastatic breast cancer and WHO performance status 0 to 2 were eligible. Pemetrexed (range, 400-2,400 mg/m2) was administered on day 1 of a 21-day schedule followed by cyclophosphamide (range, 400-800 mg/m2). Folic acid and vitamin B12 supplementation began 1 to 2 weeks before the first pemetrexed dose. Results: Fifty-seven pretreated patients were enrolled and received 342 cycles (median, 4 cycles; range, 1-26) through 14 dose levels. The MTD of pemetrexed was 2,400 mg/m2 (combined with cyclophosphamide, 600 mg/m2) with dose-limiting toxicities of grade 4 neutropenia with grade 4 infection and grade 3 diarrhea. Other grade 3 or 4 toxicities included (febrile) neutropenia, thrombocytopenia, anemia, elevated alanine aminotransferase/aspartate aminotransferase, and diarrhea. Pharmacokinetic analysis indicated that pemetrexed clearance and central volume of distribution were 40% lower than single-agent reference data, yielding a 68% increase in total systemic exposure and a 56% increase in maximal plasma concentration. Among the 50 patients evaluable for efficacy, 13 (26%) patients had a partial response and 17 (34%) patients had stable disease. Conclusions: Pemetrexed was generally well tolerated. The observed toxicities were consistent with the known toxicity profiles of pemetrexed and cyclophosphamide. Considering the MTD and the toxicity and efficacy results in this and prior studies, a low (600 mg/m2) and a high (1,800 mg/m2) dose of pemetrexed with cyclophosphamide (600 mg/m2) will be evaluated in the consecutive prospective randomized phase II study.

Joint modeling of progression-free survival and overall survival by a Bayesian normal induced copula estimation model.

In cancer clinical trials, in addition to time to death (i.e., overall survival), progression-related measurements such as progression-free survival and time to progression are also commonly used to evaluate treatment efficacy. It is of scientific interest and importance to understand the correlations among these measurements. In this paper, we propose a Bayesian semi-competing risks approach to jointly model progression-related measurements and overall survival. This new model is referred to as the NICE model, which stands for the normal induced copula estimation model. Correlation among these variables can be directly derived from the joint model. In addition, when correlation exists, simulation shows that the joint model is able to borrow strength from correlated measurements, and as a consequence the NICE model improves inference on both variables. The proposed model is in a Bayesian framework that enables us to use it in various Bayesian contexts, such as Bayesian adaptive design and using posterior predictive samples to simulate future trials. We conducted simulation studies to demonstrate properties of the NICE model and applied this method to a data set from chemotherapy-naive patients with extensive-stage small-cell lung cancer.