Unmet Clinical Need in the Management of Locally Advanced Unresectable Lung Cancer: Treatment Strategies to Improve Patient Outcomes.

Stage III locally advanced non-small cell lung cancer (LA NSCLC) comprises the most heterogeneous group of patients, accounts for one-third of patients with lung cancer, and is unresectable at presentation. Multiple treatment approaches have evolved over the past few decades focusing on timing of chemoradiation (concurrent vs. sequential) and sequencing of therapy (induction vs. consolidation). Concurrent chemoradiation (CCRT) emerged as the standard of care for the majority of the patients worldwide. Despite improvements in median and overall survival (OS) using the concurrent approach, the rate of distant failure remains high. Consolidation with chemotherapy or targeted agents, adding more radiation dose, or induction chemotherapy did not improve OS. With continued research on defining optimal radiation doses and schedules and integrating novel systemic agents, immunotherapy consolidation has renewed optimism. Synergistic use of radiation and immunotherapy can prevent micrometastatic disease and reduce local failure and may have an abscopal effect in addition to survival benefits. The PACIFIC study reported an absolute progression-free survival benefit of 11.2 months with durvalumab consolidation after standard CCRT compared with placebo. The OS data with durvalumab consolidation are encouraging. Durvalumab is the only approved immunotherapy for unresectable stage III LA NSCLC. Improved survival confirms the definitive role of durvalumab as an effective adjuvant therapy after CCRT with no new safety signals. However, the potential mechanisms driving interaction between immunotherapy and chemoradiotherapy require definitive investigation. These mechanisms may help define the timing of immunotherapy initiation as neoadjuvant, adjuvant, or consolidation and maintenance therapy after progression. FUNDING: AstraZeneca Pharma India Limited.