Jane E. Latz

Phase I and Pharmacokinetic Study of Pemetrexed Administered Every 3 Weeks to Advanced Cancer Patients With Normal and Impaired Renal Function

PURPOSE This phase I study was conducted to determine the toxicities, pharmacokinetics, and recommended doses of pemetrexed in cancer patients with normal and impaired renal function. PATIENTS AND METHODS Patients received a 10-minute infusion of 150 to 600 mg/m2 of pemetrexed every 3 weeks. Patients were stratified for independent dose escalation by measured glomerular filtration rate (GFR) into four cohorts ranging from > or = 80 to less than 20 mL/min. Pemetrexed plasma and urine pharmacokinetics were evaluated for the first cycle. Patients enrolled after December 1999 were supplemented with oral folic acid and intramuscular vitamin B12. RESULTS Forty-seven patients were treated with 167 cycles of pemetrexed. Hematologic dose-limiting toxicities occurred in vitamin-supplemented patients (two; 15%) and non-supplemented patients (six; 18%), and included febrile neutropenia (four patients) and grade 4 thrombocytopenia (two patients). Nonhematologic toxicities included fatigue, diarrhea, and nausea, and did not correlate with renal function. Accrual was discontinued in patients with GFR less than 30 mL/min after one patient with a GFR of 19 mL/min died as a result of treatment-related toxicities. Pemetrexed plasma clearance positively correlated with GFR (r2 = 0.736), resulting in increased drug exposures in patients with impaired renal function. With vitamin supplementation, pemetrexed 600 mg/m2 was tolerated by patients with a GFR > or = 80 mL/min, whereas patients with a GFR of 40 to 79 mL/min tolerated a dose of 500 mg/m2. CONCLUSION Pemetrexed was well tolerated at doses of 500 mg/m2 with vitamin supplementation in patients with GFR > or = 40 mL/min. Additional studies are needed to define appropriate dosing for renally impaired patients receiving higher dose pemetrexed with vitamin supplementation.

Phase I and Pharmacokinetic Study of Pemetrexed with High-Dose Folic Acid Supplementation or Multivitamin Supplementation in Patients with Locally Advanced or Metastatic Cancer

Purpose: This phase I study evaluated the effect of folate supplementation on the toxicity, tolerability, and pharmacokinetics of pemetrexed in patients with locally advanced or metastatic cancer. It also examined two different types of vitamin supplementation and whether the extent of prior myelosuppressive therapy affected pemetrexed tolerability. Patients and Methods: Patients received a 10-min infusion of 600 to 14,00 mg/m2 pemetrexed every 3 weeks. Patients were stratified into cohorts by pretreatment status [lightly pretreated (LPT) or heavily pretreated (HPT)] and were supplemented with intermittent high-dose folic acid (HDFA) or with continuous daily multivitamins (MVI) containing nutritional doses of folic acid. Pemetrexed plasma pharmacokinetics were evaluated for cycle 1. Results: Sixty-two HDFA patients (28 HPT and 34 LPT) were treated with 204 cycles of pemetrexed, and 43 MVI patients (20 HPT and 23 LPT) were treated with 182 cycles. Hematologic dose-limiting toxicities included grade 4 neutropenia (5 of 105 patients), grade 4 thrombocytopenia (4 of 105 patients), and febrile neutropenia (3 of 105 patients). Nonhematologic toxicities included fatigue, vomiting, diarrhea, and nausea. Pemetrexed doses of 800 and 1,050 mg/m2 were well tolerated when administered with vitamin supplementation to HPT and LPT patients, respectively. There were no clinically relevant differences in toxicities or pemetrexed pharmacokinetics for LPT versus HPT patients or for patients receiving HDFA versus daily MVI supplementation. Conclusions: The pemetrexed doses tolerated in this study with vitamin supplementation were significantly higher than those tolerated in earlier studies without supplementation, and toxicities were independent of the type of vitamin supplementation or prior myelosuppressive treatment. The recommended dose of pemetrexed is 1,050 mg/m2 in LPT patients and 800 mg/m2 in HPT patients, irrespective of the type of vitamin supplementation.

Two Drug Interaction Studies Evaluating the Pharmacokinetics and Toxicity of Pemetrexed When Coadministered with Aspirin or Ibuprofen in Patients with Advanced Cancer

Purpose: Pemetrexed is an antimetabolite that is structurally similar to methotrexate. Because nonsteroidal anti-inflammatory drugs (NSAID) impair methotrexate clearance and increase its toxicity, we evaluated the pharmacokinetics and toxicity of pemetrexed when coadministered with aspirin or ibuprofen in advanced cancer patients. Experimental Design: In two independent, randomized, crossover drug interaction studies, cancer patients with a creatinine clearance (CrCl) ≥60 mL/min received an NSAID (aspirin or ibuprofen) with either the first or the second dose of pemetrexed (cycle 1 or 2). Pemetrexed (500 mg/m2) was infused i.v. on day 1 of a 21-day cycle, and all patients were supplemented with oral folic acid and i.m. vitamin B12. Aspirin (325 mg) or ibuprofen (400 mg; 2 × 200 mg) was given orally every 6 hours, starting 2 days before pemetrexed administration, with the ninth and final dose taken 1 hour before infusion. Pemetrexed pharmacokinetics with and without concomitant NSAID treatment were compared for cycles 1 and 2. Results: Data from 27 patients in each study were evaluable for the analysis of pemetrexed pharmacokinetics. Coadministration of aspirin did not alter pemetrexed pharmacokinetics; however, ibuprofen coadministration was associated with a 16% reduction in clearance, a 15% increase in maximum plasma concentration, and a 20% increase in area under the plasma concentration versus time curve but no significant change in Vss compared with pemetrexed alone. No febrile neutropenia occurred in any patient, and no increase in pemetrexed-related toxicity was associated with NSAID administration. Conclusions: Pemetrexed (500 mg/m2) with vitamin supplementation is well tolerated and requires no dosage adjustment when coadministered with aspirin (in patients with CrCl ≥60 mL/min) or ibuprofen (in patients with CrCl ≥80 mL/min).

Randomized, double-blinded, multicenter, phase II study of pemetrexed, carboplatin, and Bevacizumab with enzastaurin or placebo in chemonaïve patients with stage IIIB/IV non-small cell lung cancer: Hoosier oncology group LUN06-116

Introduction: Bevacizumab is approved in combination with chemotherapy as first-line treatment for non-small cell lung cancer (NSCLC). Preclinical data suggest that enzastaurin and bevacizumab may have complementary effects in inhibiting angiogenesis. Methods: Eligibility criteria: ≥18 years of age, chemonaïve, stage IIIB/IV nonsquamous NSCLC, and Eastern Cooperative Oncology Group performance status 0 to 1. Patients were randomized to placebo or enzastaurin 500 mg orally daily (after a loading dose), plus pemetrexed 500 mg/m2, carboplatin area under the curve 6, and bevacizumab 15 mg/kg, intravenously, every 21 days for four cycles. Patients without progression received maintenance therapy with bevacizumab and placebo or enzastaurin. The primary objective was progression-free survival (PFS). Planned sample size was 90 patients, one-sided alpha of 0.20, with two interim analyses: one for safety and the second for futility, with a PFS hazard ratio of 0.8857. Results: Forty patients were randomized. No unique safety concerns were noted at the first interim analysis. The early stopping rule for futility was met at the second interim analysis. Median PFS was 3.5 months and 4.3 months (hazard ratio: 1.04, 95% confidence interval: 0.49–2.21), and response rates were 20% and 30% (p = 0.462) for enzastaurin and placebo, respectively. Grade 3 or 4 toxicity was similar between the two arms. Two patients died on study because of respiratory arrest and pulmonary embolism. An additional patient died of sepsis secondary to a gastrointestinal perforation >30 days after study treatment discontinuation. Conclusions: Enzastaurin does not improve efficacy when combined with pemetrexed, carboplatin, and bevacizumab. This combination does not warrant further study in NSCLC.

Pemetrexed Safety and Pharmacokinetics in Patients with Third-Space Fluid

Purpose: Pemetrexed is established as first-line treatment with cisplatin for malignant pleural mesothelioma and advanced nonsquamous non–small-cell lung cancer (NSCLC) and as single-agent second-line treatment for nonsquamous NSCLC. Because the structure and pharmacokinetics of pemetrexed are similar to those of methotrexate, and methotrexate is associated with severe toxicity in patients with third-space fluid (TSF), the safety of pemetrexed in patients with TSF was evaluated. Experimental Design: Patients with TSF (pleural effusions, ascites) and relapsed, stage III/IV NSCLC or malignant pleural/peritoneal mesothelioma were treated with pemetrexed (500 mg/m2) on day 1 of each 21-day cycle. TSF was drained at any time only if clinically indicated. Plasma samples were collected during cycles 1 and 2 to compare pemetrexed concentrations with reference data from patients without TSF. Results: Thirty-one patients with TSF received 123 pemetrexed doses (median, 4 cycles per patient; range, 1-11; mean dose intensity, 97.5%). Seven grade 3/4 drug-related toxicities, including four hematologic, were reported; there were no treatment-related deaths. There was no correlation between TSF amount and type, number, and sequelae of toxicities. Pemetrexed plasma concentrations were within the range of those in patients without TSF. Pemetrexed clearance and central volume of distribution were not statistically different between patients with and without TSF. Conclusions: No clinically relevant alterations of pemetrexed pharmacokinetics occurred in patients with TSF. Pemetrexed was well tolerated; toxicities were expected and manageable. The standard pemetrexed dose recommendations were adequate for patients with TSF in this study. These data suggest that draining TSF before administering pemetrexed is unnecessary. Clin Cancer Res; 16(10); 2872–80. ©2010 AACR.

Phase I and Pharmacokinetic Study of Pemetrexed plus Cisplatin in Chemonaive Patients with Locally Advanced or Metastatic Malignant Pleural Mesothelioma or Non ^ Small Cell Lung Cancer

Purpose: Pemetrexed is approved as monotherapy and in combination with cisplatin. The established combination dose was identified before the addition of folic acid and vitamin B12 to the treatment regimen. We evaluated the toxicity and pharmacokinetics (PK) of higher pemetrexed doses with cisplatin and vitamin supplementation. Experimental Design: Patients with malignant pleural mesothelioma or non–small cell lung cancer received pemetrexed doses from 500 to 900 mg/m2 + 75 mg/m2 cisplatin once every 21 days. Folic acid and vitamin B12 were administered per label recommendations. Results: Twenty-one patients received a combined total of 84 cycles. The maximum tolerated dose was 900 mg/m2 pemetrexed + 75 mg/m2 cisplatin. Dose-limiting toxicities at this dose included grade 3 anemia, bronchopneumonia, and neutropenia, and 1 death from sepsis secondary to grade 4 febrile neutropenia, considered possibly related to study drugs. The recommended dose was 800 mg/m2 pemetrexed + 75 mg/m2 cisplatin. Pemetrexed PK were consistent across doses; pemetrexed did not seem to affect total or free platinum PK. Conclusions: Pemetrexed with vitamin supplementation was safe and well tolerated at higher doses than the currently established 500 mg/m2 + 75 mg/m2 cisplatin. Based on this study, the recommended dose would be 800 mg/m2 pemetrexed + 75 mg/m2 cisplatin. However, recent studies showed a lack of improved efficacy for 900 or 1,000 mg/m2 single-agent pemetrexed versus 500 mg/m2 and a lack of PK/pharmacodynamic exposure-response relationship for the pemetrexed/cisplatin combination across pemetrexed exposures corresponding to this dose range. Based on currently available evidence, we recommend retaining the established dose.

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.

A Phase I and Pharmacokinetic Study of Pemetrexed Plus Irinotecan in Patients with Advanced Solid Malignancies

Purpose: The main objectives of this phase I and pharmacokinetic, open-label study were to characterize the principal toxicities and determine the maximum tolerated dose of the multitargeted antifolate pemetrexed administered in combination with irinotecan. The study also sought to detect major pharmacokinetic drug-drug interactions between these agents and preliminary evidence of antitumor activity in patients with advanced solid malignancies. Experimental Design: Pemetrexed was administered as a 10-min i.v. infusion followed by irinotecan given i.v. over 90 min every 3 weeks to patients with advanced solid malignancies. The study objectives were first pursued in heavily pretreated patients and then in lightly pretreated patients who also received vitamin supplementation. Results: Twenty-three heavily pretreated patients enrolled in the first stage of the study, and the maximum tolerated dose level of pemetrexed/irinotecan without vitamin supplementation was 400/250 mg/m2; further dose escalation was precluded by severe neutropenia that was protracted and/or associated with fever. In the second stage of the study, 28 lightly pretreated patients were administered pemetrexed/irinotecan with vitamin supplementation; these patients tolerated pemetrexed/irinotecan at a dose level of 500/350 mg/m2, which reflected clinically relevant single-agent doses of both agents. No major pharmacokinetic interactions between the agents were evident. Four patients, two patients each with colorectal cancer refractory to fluoropyrimidines and advanced mesothelioma, had partial responses. Conclusions: The pemetrexed/irinotecan regimen is well tolerated in patients with advanced solid malignancies at clinically relevant single-agent doses. The recommended dose level of pemetrexed/irinotecan for subsequent disease-directed evaluations involving lightly pretreated patients is 500/350 mg/m2 every 3 weeks with vitamin supplementation.

Population Pharmacokinetic/Pharmacodynamic Analyses of Pemetrexed and Neutropenia: Effect of Vitamin Supplementation and Differences between Japanese and Western Patients

Purpose: The objectives of the analysis were to characterize the time course of neutropenia after pemetrexed administration using an established semimechanistic-physiologic model, characterize the relationship between pemetrexed exposure and neutropenia, and describe differences in neutropenic response by vitamin supplementation status and between Japanese and Western patients. Experimental Design: An eight-compartment population pharmacokinetic/pharmacodynamic model was used to describe the absolute neutrophil count (ANC)-time profile (neutropenic response) following pemetrexed doses of 300 to 1,400 mg/m2 administered every 21 days. The analyses pooled data from 13 studies including 279 patients (161 supplemented with oral folic acid and intramuscular vitamin B12, and 118 unsupplemented; 248 Western and 31 Japanese) who received 857 treatment cycles. Results: Vitamin supplementation status, ethnic origin, and drug exposure were the dominant predictors of neutropenic response. Vitamin supplementation diminishes neutropenic response to pemetrexed. Model-predicted ANC nadirs for the “typical” Western patient receiving 500 mg/m2 pemetrexed ± vitamin supplementation were 2.74 × 109/L and 1.70 × 109/L, respectively. Japanese patients had a less pronounced neutropenic response to pemetrexed relative to Western patients. The model-predicted ANC nadir for Japanese patients receiving 500 mg/m2 pemetrexed with vitamin supplementation was 2.66 × 109/L. Values for the 1,000 mg/m2 dose with vitamin supplementation were 1.91 × 109/L and 1.34 × 109/L for Japanese and Western patients, respectively. Increased albumin, decreased cystathionine, and decreased body surface area were also associated with increased neutropenic response. Conclusions: The neutropenic response to higher pemetrexed doses administered with vitamin supplementation is tolerable. All other factors equal, Japanese patients have a lesser neutropenic response to pemetrexed relative to Western patients.

A phase II study of enzastaurin in combination with erlotinib in patients with previously treated advanced non-small cell lung cancer

INTRODUCTION Regardless of epidermal growth factor receptor (EGFR) mutation status, erlotinib improves survival for patients with advanced non-small cell lung cancer (NSCLC) after one or more chemotherapy regimens. Enzastaurin is an oral serine/threonine kinase inhibitor. This phase II study was designed to evaluate the efficacy and safety of erlotinib and enzastaurin in NSCLC, a combination with promise to overcome EGFR resistance based on preclinical models. METHODS Eligible patients with advanced NSCLC (IIIB or IV) who had failed one or two prior systemic treatment regimen(s) were enrolled and received erlotinib 150 mg/day and enzastaurin 500 mg/day (after a 1125-mg loading dose on day 1, cycle 1), both orally in 28-day cycles. The primary endpoint was progression-free survival (PFS). RESULTS From January 2008 to July 2009, 49 patients were enrolled: 29 (59%) men and 20 (41%) women; 8 (16%) were non-smokers. The median PFS was 1.7 months (one-sided 90% CI: 1.5-NA) and median overall survival (OS) was 8.3 months (95% CI: 5.3-14.3). Five patients had partial response, for an overall response rate of 10.2%; the disease control rate was 30.6% (responders+10 patients with stable disease). Grade 3-4 drug-related adverse events in ≥5% of patients were diarrhea, acne, and nausea. One possibly drug-related death due to interstitial lung disease occurred during the study. CONCLUSIONS In previously treated, unselected, advanced NSCLC patients, the addition of enzastaurin to erlotinib did not improve PFS, response, or OS compared with historical data of single-agent erlotinib, but was well tolerated.