Does chemoimmunotherapy have additional survival benefits compared to immunotherapy alone in the treatment of advanced non-small cell lung cancer?

This study was carried out to compare the effectiveness of chemoimmunotherapy (CIT) to immunotherapy (IT) alone for advanced non-small cell lung cancer (NSCLC). The authors found that there was no significant benefit in overall survival with CIT over IT.

NSCLC is the most common form of lung cancer. NSCLC is responsible for around 85% of all lung cancer diagnoses. Treatment for NSCLC is usually chemotherapy, radiotherapy, and surgical removal of tumors. Despite this, NSCLC can be difficult to treat. Recently, the development of IT has improved the outcomes of these patients.

PD-L1 is a protein that is often present in lung cancer cells. This protein prevents the immune system to detect and attack the cancer. This can make cancer more difficult to treat. IT drugs such as atezolizumab (Tecentriq) block this protein and make cancer visible to the immune system. IT as a single drug or 2 drugs combined has shown better outcomes compared to chemotherapy in patients with advanced NSCLC. However, whether there is a benefit of chemotherapy added to IT (CIT) compared to IT alone is not clear.

This study analyzed the results of 12 trials that had 7845 patients overall. Patients were treated with either IT (one drug or 2 drugs) or CIT. Patients were put in 2 groups, depending on how much PD-L1 protein they had on cancer cells. Group 1 had very few (<1%) cancer cells with PD-L1. Group 2 had low levels of PD-L1 (1-49%) and group 3 had high levels of PD-L1 (50% or more).

In patients from groups 1 and 2, the use of CIT and IT had similar survival and tumor response rates. In patients from group 2, CIT improved survival rate without cancer worsening by 41% compared to single drug-IT alone. CIT also improved the overall response rate by 2.25 times. 

There were no difference observed in overall survival with CIT compared to IT in these patients. Also, no significant differences in survival or tumor response were observed between CIT and 2 drugs-IT.

The authors concluded that CIT improved tumor response and survival without cancer worsening compared to single-drug IT in patients with high levels of PD-L1. However, there were no benefits in response rate or survival with CIT compared to 2 drugs-IT, regardless of PD-L1 status. 

This study was based on information from different clinical trials. The testing procedures and classification of PD-L1 status may have differed in the different trials.