Immunotherapy is the current treatment in non-small cell lung cancer (NSCLC). 20% of patients treated with immunotherapy have a prolonged response. What about the remaining 80%? How can we explain that some patients get no benefit from immunotherapy?

We retrospectively analyzed predictive factors of primary or secondary resistance to immunotherapy in NSCLC patients from 2 French hospitals between 2015 and 2018. Moreover, we evaluated whether PD1 inhibitor had an impact on the antitumor effects of salvage chemotherapy administered after immunotherapy. We chose to focus on taxanes.

Ninety-six patients were included in this cohort, 65(68%) patients were considered as having primary resistance and 31(32%) secondary resistance. Resistant populations did not differ. At immunotherapy initiation, median survival was 4.6 months for primary resistant patients (95%CI–4.6-6.8) and 15.6 months (95%CI–9.8-NA) for secondary resistant patients. The disease control rates with taxane were 15% in pre immunotherapy conditions vs 50% in post immunotherapy. Response rates improved regardless of the status of resistance.

This study enriches data about immunotherapy in real-life in NSCLC. Prognostic resistance factors still seem complicated to identify. The high rate of taxane responders in post immunotherapy in this retrospective cohort support the use of taxane in therapeutic escape.