Randomized phase II study of lapatinib plus capecitabine or lapatinib plus topotecan for patients with HER2-positive breast cancer brain metastases.

Approximately one-third of patients with advanced, HER2-positive breast cancer develop brain metastases. A significant proportion of women experience central nervous system (CNS) progression after standard radiation therapy. The optimal treatment in the refractory setting is undefined. This study evaluated the toxicity and efficacy of lapatinib in combination with chemotherapy among patients with HER2-positive, progressive brain metastases. Patients with HER2-positive breast cancer with progressive brain metastases after trastuzumab and cranial radiotherapy were included. The primary endpoint was CNS objective response, defined as a ≥ 50% volumetric reduction of CNS lesion(s) in the absence of new or progressive CNS or non-CNS lesions, or increasing steroid requirements. The study was closed early after 22 of a planned 110 patients were enrolled due to excess toxicity and lack of efficacy in the lapatinib plus topotecan arm. The objective response rate (ORR) in the lapatinib plus capecitabine arm was 38% (exact 95% confidence interval [CI] 13.9-68.4). No responses were observed in the lapatinib plus topotecan arm. Although the study was stopped prior to full enrollment, some promising indications of CNS activity were noted for lapatinib plus capecitabine. The combination of lapatinib plus topotecan was not active and was associated with excess toxicity.

Multicenter phase II study of lapatinib in patients with brain metastases from HER2-positive breast cancer.

PURPOSE: Brain metastases develop in one third of patients with advanced HER2+ breast cancer. Effective therapy for patients with central nervous system (CNS) progression after cranial radiation is extremely limited and represents a major clinical challenge. Lapatinib, an epidermal growth factor receptor/HER2 inhibitor, was associated with regressions of CNS lesions in a small phase 2 trial. The current study was done to further evaluate the CNS activity of lapatinib. The study was later amended to allow patients who progressed on lapatinib the option of receiving lapatinib plus capecitabine. EXPERIMENTAL DESIGN: Eligible patients had HER2+ breast cancer, progressive brain metastases, prior trastuzumab, and cranial radiotherapy. The primary end point was CNS objective response, defined as >or=50% volumetric reduction of CNS lesion(s) in the absence of increasing steroid use, progressive neurologic signs and symptoms, or progressive extra-CNS disease. RESULTS: Two-hundred and forty-two patients entered the study. CNS objective responses to lapatinib were observed in 6% of patients. In an exploratory analysis, 21% of patients experienced a >or=20% volumetric reduction in their CNS lesions. An association was observed between volumetric reduction and improvement in progression-free survival and neurologic signs and symptoms. Of the 50 evaluable patients who entered the lapatinib plus capecitabine extension, 20% experienced a CNS objective response and 40% experienced a >or=20% volumetric reduction in their CNS lesions. CONCLUSIONS: This study confirms the modest CNS antitumor activity of lapatinib. Additional responses were observed with the combination of lapatinib and capecitabine. Further studies of lapatinib-based regimens for CNS metastases from HER2+ breast cancer are warranted.

Oral versus intravenous administration of vinorelbine as a single agent for the first-line treatment of metastatic nonsmall cell lung carcinoma (NSCLC): A randomized phase II trial.

OBJECTIVES: Many patients with metastatic nonsmall cell lung carcinoma (NSCLC) cannot tolerate intravenous chemotherapy. Orally active agents would be more convenient and thus could improve their quality of life. METHODS: A total of 189 patients were randomized 2:1, 181 patients received treatment, 120 PO and 61 IV vinorelbine, 158 patients had stage IV and 31 stage IIIB disease. Among patients who received PO vinorelbine, the median age was 72 years, 62% were males; the Karnofski Performance Status (KPS) was 80-100 in 71%. These compare with a median age of 70 years, 56% male, and KPS of 80-100 in 65% of patients who received IV vinorelbine. Oral vinorelbine 60 mg/m2 was to be dose-escalated to 70 mg/m2 after the initial 3-weekly doses if there was no unacceptable toxicity. Intravenous vinorelbine was to be given 30 mg/m2 weekly. RESULTS: Five patients (4%) on PO and 8 (13%) on IV vinorelbine had a confirmed partial response, 56 (44%) and 29 (46%) had stable disease, respectively. Median time-to-disease-progression was 16.6 weeks (PO) versus 23.9 weeks (IV), and the median survival was 26 weeks (PO) versus 40.9 weeks IV vinorelbine. Median survival on PO vinorelbine for patients with KPS 60-70 was 8.3 weeks versus 43 weeks (IV). On PO vinorelbine 59 patients (57%) were dose escalated, 9 (7.5%) were dose reduced, and 10 (8.3%) did not receive PO vinorelbine at week 4. Pharmacokinetic studies confirmed PO vinorelbine exposure was significantly less than IV exposure. CONCLUSION: The inability to escalate the dose of PO vinorelbine above 60 mg/m2 weekly resulted in inferiority to IV vinorelbine at 30 mg/m2 weekly, especially in patients with poor performance status.

Structure activity relationships of 5-, 6-, and 7-methyl-substituted azepan-3-one cathepsin K inhibitors.

The syntheses, in vitro characterizations, and rat and monkey in vivo pharmacokinetic profiles of a series of 5-, 6-, and 7-methyl-substituted azepanone-based cathepsin K inhibitors are described. Depending on the particular regiochemical substitution and stereochemical configuration, methyl-substituted azepanones were identified that had widely varied cathepsin K inhibitory potency as well as pharmacokinetic properties compared to the 4S-parent azepanone analogue, 1 (human cathepsin K, K(i,app) = 0.16 nM, rat oral bioavailability = 42%, rat in vivo clearance = 49.2 mL/min/kg). Of particular note, the 4S-7-cis-methylazepanone analogue, 10, had a K(i,app) = 0.041 nM vs human cathepsin K and 89% oral bioavailability and an in vivo clearance rate of 19.5 mL/min/kg in the rat. Hypotheses that rationalize some of the observed characteristics of these closely related analogues have been made using X-ray crystallography and conformational analysis. These examples demonstrate the potential for modulation of pharmacological properties of cathepsin inhibitors by substituting the azepanone core. The high potency for inhibition of cathepsin K coupled with the favorable rat and monkey pharmacokinetic characteristics of compound 10, also known as SB-462795 or relacatib, has made it the subject of considerable in vivo evaluation for safety and efficacy as an inhibitor of excessive bone resorption in rat, monkey, and human studies, which will be reported elsewhere.