A drug that inhibits a mutated protein in some cases of lung cancer cuts mortality by half in patients with this mutation, according to results from the international Adaura clinical trial presented at the American Society of Clinical Oncology meeting in Chicago.
These results, which represent the greatest reduction in mortality ever recorded in the field of lung cancer, show how targeted therapies against tumor alterations are making oncology evolve towards more effective treatments for specific groups of patients.
In this case, the treatment has been directed against the EGFR protein, which causes uncontrolled cell proliferation in 15-20% of lung cancer cases in Europe and 30-40% of cases in Asia.
EGFR alterations are the most common type of mutation in lung cancers in non-smokers, while they are less frequent in people who have smoked, reports Margarita Majem, an oncologist at the Sant Pau Hospital in Barcelona and co-author of the clinical trial. For unknown reasons, they are also more common in women than in men.
The clinical trial involved 682 patients from 26 countries who had been surgically removed for lung cancer and whose tumor analysis had revealed that they had a mutated gene for the EGFR protein. Two-thirds of the study participants had never smoked. They had been diagnosed at a time when the cancer was located in the lung and could still be resected, which occurs in about a third of cases of the disease in Spain, but they were at high risk of cancer recurrence.
After surgery, half of the participants received osimertinib, a drug that inhibits the EGFR protein, and the other half received a placebo. Some of them had also received chemotherapy, both among those treated with osimertinib and among those who had not.
The first study results presented in 2020 indicated that treatment with osertimib reduced the risk of recurrence by one sixth in the first three years. But the question remained as to whether this benefit would be maintained with longer-term follow-up and whether it would translate into a reduction in mortality.
The survival results presented at the Chicago congress indicate that, after five years of follow-up, 22% of the participants who received placebo and 12% of those treated with osimertinib have died. Side effects associated with osimertinib were mostly mild or moderate, although 13% of patients discontinued treatment before completing the study due to its toxicity.
"We have never seen a survival improvement of this magnitude in the field of lung cancer," says Margarita Majem. "These results are going to change the way we treat these patients." Since osimertinib is already approved in Europe and available in Spain, she adds, patients will be able to benefit from this treatment improvement immediately.
Looking to the future, improvements in the early detection of lung cancer will mean that a higher proportion of cases are diagnosed when the tumor can still be resected and are candidates for treatment with osimertinib.
Transparency statement: La Vanguardia attends the American Society of Clinical Oncology congress in Chicago invited by Novartis
