A phase I and pharmacokinetic study of oral lapatinib administered once or twice daily in patients with solid malignancies.

PURPOSE: This study determined the range of tolerable doses, clinical safety, pharmacokinetics, and preliminary evidence of clinical activity following once or twice daily administration of lapatinib in patients with solid malignancies. EXPERIMENTAL DESIGN: Cancer patients (n = 81) received oral doses of lapatinib ranging from 175 to 1,800 mg once daily or 500 to 900 mg twice daily. Clinical assessments of safety and antitumor activity were recorded and blood was sampled for pharmacokinetic assessments. The effect of a low-fat meal on lapatinib pharmacokinetics was assessed in a subset of patients. RESULTS: Lapatinib was well tolerated, such that dose escalation was limited at 1,800 mg once daily only by pill burden. Twice-daily dosing was implemented to further explore tolerability, and was limited by diarrhea to 500 mg twice daily. The most commonly reported adverse events with once-daily dosing were diarrhea (48%), nausea (40%), rash (40%), and fatigue (38%) and with twice-daily dosing were diarrhea (85%), rash (54%), and nausea (34%). Lapatinib serum concentrations accumulated upon repeated dosing, increasing nearly in proportion with dose, and were significantly increased when dosed with food or administered twice daily. One patient with head and neck cancer achieved a confirmed complete response and 22 patients had stable disease of >or=8 weeks including three patients with stable disease of >10 months (renal, lung, and salivary gland cancers). CONCLUSION: Lapatinib was well tolerated following once and twice daily administration. Systemic exposure to lapatinib was dependent on the dose, duration and frequency of dosing, and prandial state. Clinical activity was observed.

Phase I and pharmacokinetic study of lapatinib in combination with capecitabine in patients with advanced solid malignancies.

PURPOSE: This phase I trial (EGF10005) assessed the safety, optimally tolerated regimen (OTR), and pharmacokinetics of lapatinib and capecitabine in combination in patients with advanced solid malignancies. PATIENTS AND METHODS: Patients with previously treated, advanced solid malignancies were eligible. Cohorts of at least three patients each received once-daily oral lapatinib (continuous) and capecitabine (twice daily for 14 days every 21 days). Doses of lapatinib and capecitabine were escalated based on dose-limiting toxicities in the first treatment cycle until the OTR was reached. Additional patients were treated at the OTR dose level to further evaluate safety and for pharmacokinetic analyses. RESULTS: Forty-five patients were treated in the study. The OTR was determined to be lapatinib 1,250 mg/d plus capecitabine 2,000 mg/m(2)/d. The majority of drug-related adverse events were grade 1 to grade 2 in severity, with few grade 3 and no grade 4 toxicities. The most common drug-related toxicities (> 15% of patients) were diarrhea, nausea, rash, palmar-plantar erythrodysesthesia, mucositis, vomiting, and stomatitis. There were four confirmed responses (one complete response and three partial responses). The pharmacokinetics (area under the curve and maximum concentration) of lapatinib, capecitabine and its metabolites, fluorouracil, and alpha-fluoro-beta-alanine, were not meaningfully altered by coadministration. CONCLUSION: Lapatinib and capecitabine administered on a 3-week schedule were well tolerated, and no pharmacokinetic interaction was observed. Clinical activity was observed in patients with previously treated, advanced solid malignancies.

Phase I pharmacokinetic study of the safety and tolerability of lapatinib (GW572016) in combination with oxaliplatin/fluorouracil/leucovorin (FOLFOX4) in patients with solid tumors.

PURPOSE: This phase I study was designed to determine the optimally tolerated regimen (OTR), safety, and clinical activity of lapatinib in combination with FOLFOX4 [oxaliplatin/leucovorin/5-fluorouracil (5-FU)] in patients with solid tumors. Furthermore, the pharmacokinetics of lapatinib, oxaliplatin, and 5-FU when given alone and in combination were evaluated. EXPERIMENTAL DESIGN: This study was conducted in two parts. Part 1 was designed to determine the OTR and part 2 was the pharmacokinetic part of the study. Lapatinib was administered once daily for the entire duration of the study. Leucovorin and oxaliplatin were given concurrently over 2 h as an i.v. infusion, after which 5-FU was given as a bolus followed by continuous infusion over 22 h on day 1. 5-FU and leucovorin administration were repeated in an identical manner on day 2. Cycles were repeated every 2 weeks. Once the OTR was determined, it was to become the dose level for patients included in the pharmacokinetic part of the study. RESULTS: A total of 34 patients was treated in this study. No dose-limiting toxicities were observed and the OTR was established at 1,500 mg/d lapatinib in combination with the standard FOLFOX4 regimen. Nonhematologic toxicities consisted mainly of nausea, diarrhea, vomiting, fatigue, neuropathy, and mucositis. The most important hematologic toxicity was neutropenia. No drug-drug interactions between lapatinib and the FOLFOX4 regimen were observed. CONCLUSION: Lapatinib can be safely administered in combination with the standard FOLFOX4 regimen. Further studies are warranted to explore the potential additive antitumor effect of lapatinib in combination with the FOLFOX4 regimen.

A pilot study of edrecolomab (Panorex, 17-1A antibody) and capecitabine in patients with advanced or metastatic adenocarcinoma.

Edrecolomab (Panorex) is a monoclonal antibody directed against the 17-1A antigen located on the cell surfaces of carcinomas. Clinical activity has been seen in colon and breast cancer. This trial investigated the feasibility of combining edrecolomab with the oral fluoropyrimidine capecitabine (Xeloda). Patients received a loading dose of edrecolomab 500 mg intravenously (i.v.) on day--14, followed 2 weeks later by 100 mg i.v. every 28 days (day 1). Capecitabine was administered to single-patient cohorts at escalating doses of 1500, 2000, and 2500 mg/m2/day in two equally divided doses for 14 of 21 days, beginning on day 1. Additional patients were enrolled at the 2500 mg/m2/day dose level to better define the toxicities of combination therapy. Toxicity assessment was the primary endpoint. Twenty seven patients with advanced or metastatic adenocarcinoma were enrolled on this study: 20 were evaluable for toxicity and 18 for response. The most common toxicities were elevated liver enzymes, diarrhea, and hand-foot syndrome. In cycle 1, grade 3 hand-foot syndrome was seen in two patients, and grade 3 diarrhea in one patient. Grade 2 toxicities included diarrhea, hand-foot syndrome, anemia, leukopenia, and transaminitis. Cumulative hand-foot syndrome was observed in four patients treated beyond two cycles. Three patients had edrecolomab infusion reactions during the course of treatment. One complete response and two partial responses were seen. Nine patients had disease stabilization lasting a median of 17.5 weeks (range 14.5-28+). Edrecolomab and capecitabine may be safely given in combination to patients with advanced or metastatic adenocarcinoma. Clinical activity is seen in this heavily pretreated patient population.