A large study in advanced lung cancer has shown that immunotherapy improves survival and reduces side effects compared to standard chemotherapy. Explanations.
Immunotherapy is more effective and better tolerated than chemotherapy in the treatment of advanced lung cancer (locally advanced or metastasized), one of the most common forms of lung cancer, according to a large study presented to the American Cancer Congress ASCO since it represents almost two-thirds. Indeed, the diagnosis of these cancers is quite late and only a third of patients can benefit from a complete surgical resection.
In patients with an advanced form of non-small cell lung cancer and with PD-L1 marker expression on at least 1% of the tumor cells, pembrolizumab (a monoclonal antibody) as monotherapy improves survival from 4 to 8 months and reduces the frequency of severe side effects (grade 3 to 5) compared to chemotherapy (18% vs 41%).
A very large study
PD-L1 is a biomarker which is used to screen for patients likely to respond to “checkpoint inhibitor” type immunotherapies. In general, tumors which have high PD-L1 expression respond better to these treatments, but some tumors which have low or no expression may respond to anti-PD1 / anti-PD-L1.
The KEYNOTE-042 study is a large study which compared the efficacy and safety of an immunotherapy, pembrolizumab, in 1274 patients with traditional chemotherapy. Advanced lung cancers (squamous or non-squamous) were included in the study when PD-L1 expression was on at least 1% of the tumor cells.
Efficacy as a function of PD-L1 expression
In other studies, pembrolizumab has been associated with efficacy from PD-L1 expression greater than 1%. Analysis of the results was also performed according to the level of PD-L1 expression.
With 50% or greater PD-L1, survival on pembrolizumab is 20 months versus 12.2 months on chemotherapy. For a PD-L1 expressed at more than 20%, the survival times are 17.7 months versus 13 months respectively and with a PD-L1 at 1% or more, these are 16.7% versus 12.1% , respectively. The response to chemotherapy is of course constant according to the groups, but we see that if the response is better with a PD-L1 expressed at more than 50%, pembrolizumab still works with lower expression levels.
This is therefore the first study to demonstrate the superiority of pembrolizumab as monotherapy compared to chemotherapy based on platinum salts. Do you have to do without chemotherapy? Not necessarily, it would first be necessary to verify that the combination of immunotherapy + chemotherapy does not do better than immunotherapy alone, which is not yet clear.
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