Ramucirumab plus atezolizumab in patients with stage IV non-small cell lung cancer previously treated with immune checkpoint inhibitors

Objectives: The treatment options for patients with stage IV non-small cell lung cancer (NSCLC) who develop tumor progression after platinum-based chemotherapy and immune checkpoint inhibitors (ICIs) are limited. The combination of ICI with inhibitors of vascular endothelial growth receptor (VEGFR) signaling has shown promising results in previously untreated patients. Materials and Methods: In this single institution phase II study, patients with advanced stage NSCLC previously treated with at least one line including ICI received ramucirumab 10 mg/kg and atezolizumab 1,200 mg intravenously every 21 days until tumor progression or intolerable toxicity. The primary endpoint was overall response rate (ORR) by the RECIST 1.1 criteria according to the investigator assessment. Secondary endpoints included clinical benefit rate (CBR), overall survival (OS), progression-free survival (PFS) and tolerability. Results: Twenty-one patients were enrolled between June 2019 and April 2021. The median age was 67 (range 42-82), 17 (81 %) were female, and 15 (71 %) had non-squamous histology. The median number of prior systemic treatment lines and prior ICI lines were 3 (range 2-8) and 1 (range 1-3), respectively. One patient achieved a complete response for an ORR of 4.8 % while 16 (76.2 %) had stable disease with a CBR of 80.9 %. The median PFS was 3.4 months, and the median OS was 16.5 months. The most common adverse events included hypertension (86 %), proteinuria (67 %), and nausea (52 %). Grade 3 or 4 events were seen in 9 (43 %) of patients, with hypertension being the most common (33 %) of the grade 3 or 4 events. Conclusions: Although the primary endpoint of ORR was not met, the combination of ramucirumab plus atezolizumab was associated with a high CBR and the OS was better than expected in heavily pretreated patients. Therefore, further investigation with ICI plus VEGF inhibition is warranted.

Automated summary

This single institution phase II study investigated the combination of ramucirumab and atezolizumab in heavily pretreated patients with advanced NSCLC. Although the primary endpoint of overall response rate was not met, the treatment showed a high clinical benefit rate and overall survival better than expected. Further research on the combination of immune checkpoint inhibitors and VEGF inhibition is warranted.