C-MET inhibitors in the treatment of lung cancer

OPINION STATEMENT

Lung cancer is the most common malignant neoplasm and constitutes the most common neoplastic cause of death globally. The results of therapies employing standard chemotherapy are unsatisfactory. Currently, efforts are being made to personalize the therapy; numerous clinical studies are being conducted around the world to assess the efficacy and safety of agents directed at molecular targets. One of these molecular targets is the c-MET proto-oncogene, whose primary ligand is hepatocyte growth factor (HGF). C-MET hyperactivity has been observed in numerous neoplasms, including non-small-cell lung carcinoma. Prolonged or continuous activity of the receptor leads to excessive cell proliferation and is related to the development or progression of neoplastic disease. C-MET inhibitors can be classified into three groups: small-molecule tyrosine kinase inhibitors of the c-MET receptor (crizotinib, tivantinib, cabozantinib, foretinib), as well as monoclonal antibodies against c-MET (onartuzumab) and against the HGF ligand (ficlatuzumab, rilotumumab). The efficacy and safety of these agents is assessed both in monotherapy and in combination with other molecularly targeted agents. Furthermore, the toxicity profile of c-MET inhibitors is completely different from that of standard chemotherapy. The best understood c-MET inhibitor used in the treatment of non-small-cell lung carcinoma patients is crizotinib. It is registered for patients with the presence of ALK gene rearrangements after the failure of the first line of treatment based on platinum derivatives. The purpose of this present paper is to present clinical studies that assessed the efficacy and safety of c-MET inhibitors for the treatment of non-small-cell lung carcinoma, as well as current indications for the use of these molecules.

The role of pharmacoethnicity in the development of cytotoxic and molecular targeted drugs in oncology

The effective and toxic ranges of anticancer drugs are very narrow and, in some cases, inverted. Thus determination of the most appropriate dosage and schedule of administration is crucial for optimal chemotherapy. In common arm trials conducted in Japan and by Southwest Oncology Group (SWOG) that used the same doses and schedules for the administration of carboplatin plus paclitaxel, the frequency of hematological toxicity was significantly higher in the Japanese trials than in the SWOG trial, despite demonstrating similar response rates. The frequency of epidermal growth factor receptor (EGFR) mutations in tumors was significantly higher among East Asian populations, and these populations are also reported to demonstrate a higher response rates to epidermal growth factor receptor tyrosine-kinase inhibitors (EGFR-TKIs). The prevalence of interstitial lung disease induced by treatment with EGFR-TKIs has been shown to be quite high in the Japanese population. Clinical trials of cetuximab against non-small cell lung cancer and of bevacizumab against stomach cancer have shown that these agents are only active in Caucasians. In a trial examining the use of sorafenib after transarterial chemoembolization in Korean and Japanese patients with advanced hepatocellular carcinoma, the compliance and dose intensity of the drug were quite low compared with other trials. Although not only identified pharmacogenomics differences but also differences in social environment, and regional medical care, including pharmacoeconomics strongly influence ethnic differences in treatment response, further identification and understanding of the pharmacogenomics underlying ethnic differences will be essential to timely and reliable global development of new anticancer drugs.

Differences in outcome and toxicity between Asian and caucasian patients with lung cancer treated with systemic therapy

It is increasingly recognized that differences in overall survival and toxicity exist between Asian and caucasian patients with small-cell and non-small-cell lung cancer, with a longer survival, higher response rates and greater toxicity to chemotherapy and targeted therapy reported in Asian patients. Two global studies are used to illustrate how the proportions of Asian patients can influence survival outcome. Ethnicity is an important and complex characteristic that should considered in the design and conduct of a global clinical study, as the safety, tolerability and response may vary between Asian and caucasian patients. Whether ethnic differences in lung cancer survival are attributed to genetic differences among races or are simply a surrogate marker of differences in access to healthcare because of socioeconomic differences is unclear. Carefully designed prospective studies investigating ethnic-specific determinants of sensitivity and toxicity to systemic therapy are warranted.

A phase I dose-escalation study of Tivantinib (ARQ 197) in adult patients with metastatic solid tumors

BACKGROUND

Tivantinib, an oral, non-ATP competitive, selective c-MET inhibitor, exhibited antitumor activity in preclinical models. This open-label, phase I, dose-escalation study evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics of tivantinib in patients with advanced or metastatic solid tumors refractory to standard therapy.

METHODS

Thirteen dose levels of tivantinib ranging from 10 to 360 mg twice a day were administered to patient cohorts in 21-day cycles (14 days on/7 days off); three active pharmaceutical ingredient forms of tivantinib (amorphous, crystalline A, and crystalline B) were also investigated. Treatment was continued until the occurrence of unacceptable toxicity, tumor progression, patient withdrawal, or death.

RESULTS

A total of 79 patients with advanced solid tumors were enrolled. A maximum tolerated dose was not determined. Tivantinib was well tolerated, with mild to moderate toxicities. Two patients discontinued the study drug due to treatment-emergent adverse events. Dose-limiting grade of 3 or more toxicities including leukopenia, neutropenia, thrombocytopenia, vomiting, and dehydration, were observed in 2 patients treated with tivantinib 360 mg twice a day. The rate of absorption of tivantinib peaked approximately 2 to 4 hours after initial dosing, followed by a linear decrease in plasma concentrations. Increases in tivantinib exposure were not dose proportional. There was significant interpatient pharmacokinetic variability; however the clinical safety of tivantinib seemed unaffected. Three patients (3.8%) achieved a partial response and 40 patients (50.6%) maintained stable disease for a median of 19.9 weeks.

CONCLUSIONS

Tivantinib 360 mg twice a day was well tolerated in patients with refractory advanced solid tumors. The results of this trial warrant further clinical investigation. Clin Cancer Res; 17(24); 7754-64. ©2011 AACR.