Examining Recent PACIFIC Trial Updates for Durvalumab in Locally Advanced NSCLC

David Spigel, MD, chief scientific officer of Sarah Cannon Research Institute, gives a recap on the phase III PACIFIC study, with facts and perceptions surrounding the latest data that study researchers reported during the 2019 ASCO Annual Meeting.

Three years ago, the PACIFIC study resulted in a reduction in risk of death in patients with locally advanced, unresectable non—small cell lung cancer (NSCLC) receiving durvalumab (Imfinzi) following chemoradiotherapy. Although the median overall survival still has not been reached in the durvalumab arm compared with 29.1 months in the placebo arm, the latest data also show a substantial reduction in the risk of death for durvalumab treatment, with a hazard ratio of 0.69 (95% CI, 0.55-0.86). This shows consistency in the efficacy and safety of treatment with durvalumab for patients with locally advanced NSCLC, even after 3 years, says Spigel.

Patients in the PACIFIC trial also demonstrated a longer progression-free survival when receiving durvalumab compared with placebo (16.8 months versus 5.6 months; HR, 0.52; 95% CI, 0.42-0.65;P<.001). The results were consistent regardless of PD-L1 status and included patients with a PD-L1 tumor proportion score (TPS) of 0.

In early 2019, it was reported that the PACIFIC study left unresolved questions related to PD-L1 consideration during the treatment of NSCLC with immunotherapy. With these questions in mind, Spigel comments on the controversaries that arose after the European Union required oncologists to consider levels of PD-L1 expression when selecting patients for treatment with durvalumab. There is no such indication in the United States, which leaves some clinicians unsure about the drug&rsquo;s safety for patients with negative PD-L1 expression.