Merck & Co/MSD’s Keytruda (pembrolizumab) doubled the five-year survival rate for patients with metastatic non-small cell lung cancer (NSCLC) with PD-L1 tumour expression.
The long-term data, from the phase 3 KEYNOTE-024 trial, demonstrated that treatment with Keytruda led to a sustained survival benefit and durable responses, when compared to chemotherapy in PD-L1-positive NSCLC.
At the five-year time point, the overall survival rate for patients receiving Keytruda was twice as high compared to chemotherapy (31.9% and 16.3% respectively). The checkpoint inhibitor also reduced the risk of death by 38% versus chemotherapy, with a median overall survival rate of 26.3 months for Keytruda compared to 13.4 months for placebo.
Alongside the overall survival rate data, Merck also revealed that the median duration of response for Keytruda was 29.1 months, nearly five times the response observed in the chemotherapy arm (6.3 months).
In addition, of the patients who had completed two years of treatment with Keytruda, 81.4% were alive after five years and nearly half (46%) remained treatment-free.
“It is…noteworthy that at five years, 81.4% of patients who completed two years of treatment with Keytruda were alive and nearly half of these patients remained treatment-free, representing an encouraging new precedent in the first-line metastatic non-small cell lung cancer setting,” said Roy Barnes, senior vice president and head of global clinical development at Merck Research Laboratories.
Keytruda has become the new standard-of-care treatment for newly diagnosed NSCLC, after first winning approval in October 2015.
Since then, the immunotherapy has added an array of indications to its arsenal, including approvals for the treatment of head and neck squamous cell carcinoma, classical Hodgkin lymphoma (cHL), cervical cancer, renal cell carcinoma (RCC) and a host of other tumour types.
In 2019, the US Food and Drug Administration (FDA) approved an expanded label for Keytruda as a monotherapy treatment in the first-line setting for advanced PD-L1-positive NSCLC patients, widening its scope and reinforcing its dominance in this cancer type.
Although Keytruda holds much of the NSCLC market, other immunotherapies have carved a niche in the treatment of small cell lung cancer, one of the only tumour types that Merck’s treatment appears not to work in.
That includes Roche’s PD-L1 inhibitor Tecentriq (atezolizumab) which is approved for first-line SCLC. AstraZeneca’s Imfinzi (durvalumab) also recently demonstrated promise in this less common lung cancer type, improving overall survival for patients by 27% compared to chemotherapy.
SCLC accounts for around 10-15% of all cases of lung cancer and has a poor prognosis with a five-year survival rate of approximately 6% across all stages of the disease at diagnosis.