Risk factors associated with palbociclib-induced neutropenia in patients with metastatic breast cancer.

BACKGROUND: Neutropenia is the most common adverse event with palbociclib, an oral cyclin-dependent kinase 4/6 inhibitor, with grade 3/4 neutropenia occurring in up to 67% of patients in phase III trials evaluating this agent in metastatic breast cancer. This retrospective chart review assessed characteristics of patients on palbociclib to evaluate for risk factors in the development of grade 3/4 neutropenia. PATIENTS AND METHODS: Patients with metastatic breast cancer who received palbociclib were included. Patient demographics collected included age, gender, race, body mass index, breast cancer treatment history, palbociclib starting dose, baseline absolute neutrophil count, baseline platelet count, concomitant hormonal therapy, concomitant use of denosumab, and use of concomitant strong CYP3A4 inhibitors/inducers. Events of interest occurring within 30 days of initiation of palbociclib were also noted including antibiotic and corticosteroid use, mucosal conditions, open wounds, or surgery. The incidence and potential risk factors for grade 3/4 neutropenia in the first 6 months of treatment were analyzed. RESULTS: A total of 257 patients were included in the analysis with 206 patients (80.2%) and 139 patients (54.1%) experiencing all-grade neutropenia and grade 3/4 neutropenia, respectively. Multivariate analysis found baseline myelosuppression and recent antibiotic use to be independent predictors of grade 3/4 neutropenia. Normal weight patients had an increased risk for grade 3/4 neutropenia compared to obese patients by multivariate analysis. CONCLUSION: The results of this study showed baseline myelosuppression and recent antibiotic use within 30 days of palbociclib initiation were predictive of a higher incidence of grade 3/4 neutropenia. Obese patients were less likely to develop grade 3/4 neutropenia compared to normal weight patients.

Multicenter trial of EC145 in advanced, folate-receptor positive adenocarcinoma of the lung.

BACKGROUND: EC145 is a novel folate-receptor targeted agent consisting of a folate molecule linked to a vinca alkaloid. EC20 is a technetium-labeled folate that assesses the presence of folate receptors (FR) in vivo. The objective of this study was to determine the activity of EC145 in patients with chemotherapy refractory lung adenocarcinoma, whose tumors expressed the FR as determined by EC20 imaging. METHODS: Patients with advanced adenocarcinoma of the lung, Eastern Cooperative Oncology Group performance status 0 to 2, normal organ function, those who had progressed after at least two prior cytotoxic regimens, and with EC 20 uptake in at least one index lesion were eligible. The primary objective of the study was the ability to receive four or more cycles of therapy. RESULTS: Sixty patients were screened and 43 patients were enrolled. Eleven patients (26%) received more than four cycles (95% confidence interval [CI] 14%, 41%), and one patient had partial response (response rate (RR) = 2.3%, 95% CI 0%, 12%). Patients in whom all target tumor lesions expressed FR by EC 20 scans had a trend toward superior results in terms of clinical benefit response (50% versus 14.3 %; p = 0.10) and survival (47.2 weeks versus 14.9 weeks [HR = 0.539, p = 0.101]) compared with those in whom at least one but not all target lesions were positive for FR (FR+). CONCLUSION: EC145 demonstrated clinical activity with a good toxicity profile in this population. Uniform uptake of EC20 may predict activity of EC145 and be useful for prospective selection of patients in future trials.

A randomized phase II trial of first-line treatment with gemcitabine, erlotinib, or gemcitabine and erlotinib in elderly patients (age ≥70 years) with stage IIIB/IV non-small cell lung cancer.

INTRODUCTION: Single-agent gemcitabine is a standard of care for elderly patients with advanced non-small cell lung cancer, but novel therapies are needed for this patient population. METHODS: We performed a noncomparative randomized phase II trial of gemcitabine, erlotinib, or the combination in elderly patients (age ≥70 years) with stage IIIB or IV non-small cell lung cancer. Patients were randomized to arms: A (gemcitabine 1200 mg/m on days 1 and 8 every 21 days), B (erlotinib 150 mg daily), or C (gemcitabine 1000 mg/m on days 1 and 8 every 21 days and erlotinib 100 mg daily). Arms B and C were considered investigational; the primary objective was 6-month progression-free survival. RESULTS: Between March 2006 and May 2010, 146 eligible patients received protocol therapy. The majority of the patients (82%) had stage IV disease, 64% reported adenocarcinoma histology, 90% reported current or previous tobacco use, and 28% had a performance status of 2. The 6-month progression-free survival rate observed in arms A, B, and C was 22% (95% confidence interval [CI] 11-35), 24% (95% CI 13-36), and 25% (95% CI 15-38), respectively; the median overall survival observed was 6.8 months (95% CI 4.8-8.5), 5.8 months (95% CI 3.0-8.3), and 5.6 months (95% CI 3.5-8.4), respectively. The rate of grade ≥3 hematological and nonhematological toxicity observed was similar in all three arms. The best overall health-related quality of life response did not differ between treatment arms. CONCLUSIONS: Erlotinib or erlotinib and gemcitabine do not warrant further investigation in an unselected elderly patient population.