Immunotherapy drug holds promise for lung cancer patients

19 Apr 2015

The immunotherapy pembrolizumab was found to be safe and yielded durable responses in patients with advanced, non-small cell lung cancer (NSCLC). In addition, patients with high levels of the protein PD-L1 as a biomarker in their tumors had better clinical outcomes, according to phase I KEYNOTE-001 clinical trial data.

 “Results from the training cohort of KEYNOTE-001 to assess PD-L1 expression in tumor cells showed that NSCLC patients whose tumors expressed PD-L1 by immunohistochemistry in at least half of the cancer cells had the most favorable outcomes with pembrolizumab treatment,” said Edward B. Garon, MD, associate professor of medicine at the David Geffen School of Medicine at the University of California, Los Angeles.

“The largest data set of lung cancer patients treated with a checkpoint inhibitor”

In the study, 495 patients participated providing valuable data which showed that:

  • The overall response rate (ORR) for the entire 495 patients was 19%.
  • The median duration of response exceeded a year among responders regardless of the degree of PD- L1 expression, which is one of the exciting outcomes with this class of drug.
  • Approximately a quarter of screened patients had PD-L1 expression in at least half of their tumor cells.
  • For patients with 1% to 49% and less than 1% tumor PD-L1 expression, the ORRs were 16.5% and 10.7%, respectively.
  • After a median of 10.9 months of follow-up, among patients with PD-L1 expression in at least half of their cancer cells, the median overall survival has not been reached in those who were treatment-naïve or those who had been previously treated.

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According to Edward B. Garon “this study in addition to being the largest data set of lung cancer patients treated with a checkpoint inhibitor, it is the first confirmation in an independent validation cohort that PD-L1 expression is clearly a marker of response”.

Measurable side effects

In general, the side effect profile was favorable, with less than 10% of patients experiencing grade 3 or greater drug-related adverse events, Garon noted. Other immune-related adverse events occurring in at least 2% of the patients were infusion reactions and hypothyroidism.

There was one drug- related death, resulting from pneumonitis, which was seen in 3.6% of patients, being grade 1 or 2 in half of the cases.

Neither the drug nor the biomarker test is approved for use in this setting at this time, but if I had a patient whose tumor had PD-L1 expression on at least half of the cells and if pembrolizumab was available, I think that I would find the data compelling to look at the drug as the treatment option for that patient,” Garon said.

 

Source: eCancer News
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