Evaluating the safety and effectiveness of pembrolizumab in elderly patients with advanced non-small cell lung cancer

This study investigated the safety and effectiveness of pembrolizumab (Keytruda) in patients of 75 years or older with PD-L1 positive non-small-cell-lung cancer (NSCLC). Authors concluded that pembrolizumab improved overall survival and was safer than chemotherapy in these patients.

Lung cancer is one of the most common cancer worldwide. More than 50% of cases are diagnosed in those aged 65 years or more. However, patients in this age group (in particular those over 75 years) are underrepresented in clinical trials. Therefore, there is less of an evidence base for cancer treatment in these patients.

Immune-based therapies are used widely for NSCLCs and have been associated with better patient outcomes. They include treatments targeting a molecule called PD 1. An example of a PD 1 targeting drug is pembrolizumab. This is an antibody used to treat PD-L1 positive NSCLC. More data, specifically from patients over 75 years with NSCLC, is needed to determine whether pembrolizumab is effective for treating NSCLC in the elderly population. 

This study included 264 patients of 75 years and older from 3 different studies. These studies had each involved patients with advanced, PD-L1-positive NSCLC. In each study, pembrolizumab had been compared with another chemotherapy agent or regimen. Patients were grouped according to age into two groups, 75 and older and younger than 75 years of age. The average follow-up time was 11.7 months in the older group.

The average time of treatment in the elderly group was 5.6 months for pembrolizumab and 3.5 months for chemotherapy. In elderly patients (75 years or older), pembrolizumab gave an overall survival (OS) of 15.7 months. This was compared to 11.7 months in the chemotherapy group. These patients had received no prior treatment. 

In those aged 75 and older from 2 studies where patients had received previous treatment for NSCLC, pembrolizumab also improved OS in comparison to chemotherapy (27.4 months vs 7.7 months).

Side effects occurred less frequently in the pembrolizumab group (68.5%) compared to the chemotherapy group (94.3%).

This study concluded that pembrolizumab improved overall survival and had a more tolerable profile compared to chemotherapy in patients aged 75 years and older with PD-L1 positive NSCLC.

Larger studies with patients ≥75 years only are required in order to confirm the findings. This study was also funded by Merck Sharp & Dohme, who manufacture pembrolizumab.