Navigating First-Line Treatment Selection in a Crowded Biomarker Landscape

With 4 ROS1-directed TKIs now in the mix, community oncologists need a clear framework for sequencing and CNS considerations in this rare NSCLC subset.

Crizotinib (Xalkori), the earliest approved agent, demonstrated strong systemic efficacy but limited central nervous system) CNS penetration — a critical limitation given that patients with ROS1-positive non-small cell lung cancer (NSCLC) have a high propensity for brain metastases. Entrectinib (Rozlytrek) emerged as an important alternative with meaningful intracranial activity, offering both systemic and CNS disease control in the first-line setting.

More recently, next-generation TKIs repotrectinib (Augtyro) and taletrectinib (Ibtrozi) have entered the landscape with data showing deeper and more durable responses, improved CNS penetration, and the ability to overcome resistance mutations — including ROS1 G2032R — that can limit the efficacy of earlier-generation agents.

In practice, sequencing decisions should account not only for systemic response but also for baseline CNS involvement, resistance mutation profiles, and tolerability. For patients with active, symptomatic brain metastases, an agent with robust intracranial activity should be prioritized upfront. In the community setting, ensuring comprehensive molecular profiling at diagnosis — including ROS1 FISH or next-generation sequencing — remains the critical first step before any treatment decision is made.