Moving Beyond 3+3: The Future of Clinical Trial Design

Misgivings have been raised about the operating characteristics of the canonical 3+3 dose-escalation phase I clinical trial design. Yet, the traditional 3+3 design is still the most commonly used. Although it has been implied that adhering to this design is due to a stubborn reluctance to adopt change despite other designs performing better in hypothetical computer-generated simulation models, the continued adherence to 3+3 dose-escalation phase I strategies is more likely because these designs perform the best in the real world, pinpointing the correct dose and important side effects with an acceptable degree of precision. Beyond statistical simulations, there are little data to refute the supposed shortcomings ascribed to the 3+3 method. Even so, to address the unique nuances of gene- and immune-targeted compounds, a variety of inventive phase 1 trial designs have been suggested. Strategies for developing these therapies have launched first-in-human studies devised to acquire a breadth of patient data that far exceed the size of a typical phase I design and blur the distinction between dose selection and efficacy evaluation. Recent phase I trials of promising cancer therapies assessed objective tumor response and durability at various doses and schedules as well as incorporated multiple expansion cohorts spanning a variety of histology or biomarker-defined tumor subtypes, sometimes resulting in U.S. Food and Drug Administration approval after phase I. This article reviews recent innovations in phase I design from the perspective of multiple stakeholders and provides recommendations for future trials.

C-MET inhibitors for advanced non-small cell lung cancer

INTRODUCTION

The role of the c-mesenchymal-epithelial transition factor (c-MET) signaling pathway in tumor progression and invasion has been extensively studied. C-MET inhibitors have shown anti-tumor activity in NSCLC both in preclinical and in clinical trials. However, given the molecular heterogeneity of NSCLC, it is likely that only a specific subset of NSCLC patients will benefit from c-MET inhibitors. Emerging data also suggest that MET inhibitors in combination with EGFR-TKIs (epidermal growth factor receptor tyrosine kinase inhibitors) may have a role in therapy for both EGFR-TKI resistant and EGFR-TKI naïve patients. The challenges ahead are in the identification of the molecular subtypes that benefit most.

AREAS COVERED

This review summarizes the current understanding of c-MET biology in relation to studies evaluating c-MET inhibitors in the treatment of NSCLC.

EXPERT OPINION

MET inhibitors have the potential to benefit subsets of NSCLC patients with specific genetic alterations. Exon-14 skipping mutations appear so far to be the most promising molecular subset that is sensitive to MET inhibitors, whereas overexpression, amplification and point mutations of MET seem more challenging subgroups to target. Combination with other target agents, such as EGFR inhibitors, may represent a promising therapeutic strategy in specific areas (e.g. EGFR-TKI resistance).