A drug that inhibits a protein mutated in some cases of lung cancer cuts mortality in half in patients who have this mutation, according to the results of an international clinical trial presented at the congress of the American Society of Clinical Oncology in celebrates in Chicago.
These results, which represent the most important reduction in mortality ever recorded in the field of lung cancer, show how therapies aimed at altering tumors are evolving oncology towards more effective treatments for specific groups of patients.
In this case, the treatment has been directed against the EGFR protein, which causes an uncontrolled proliferation of cells 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, reports Margarita Majem, oncologist at Sant Pau hospital in Barcelona and co-author of the clinical trial. They are less common in people who have smoked because they have accumulated a large number of different mutations caused by smoking. For unknown reasons, EGFR mutations are also more common in women than in men.
682 patients from 26 countries participated in the clinical trial, who had undergone surgical resection of lung cancer. Analyzes of their tumors revealed that they had mutated genes for the EGFR protein.
Two-thirds of the participants in the study had never smoked. They had been diagnosed at a time when the cancer was localized in the lung and could still be resected, which happens in approximately one third of cases of the disease in Spain, but they had a 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, moreover, had received chemotherapy, both among those who had been treated with osimertinib and among those who had not.
The first results of the study, presented in 2020, indicated that treatment with osertimibe reduced the risk of relapse by a sixth in the first three years. But the question remained whether this benefit would be maintained with longer-term follow-up and whether it would translate into a reduction in mortality.
Survival results presented at the Chicago congress indicate that, after five years of follow-up, 22% of participants who received placebo and 12% of those treated with osimertinib had died. Side effects related to osimertinib were mostly mild or moderate, although 13% of patients discontinued treatment before completing the study due to toxicity.
"We had never seen an improvement in survival of this magnitude in the field of lung cancer", declares Margarita Majem. "These results will change the way we treat these patients."
Given that osimertinib is already approved in Europe and available in Spain, patients will be able to benefit from this improvement in treatment immediately.
Looking ahead, the improvement in early detection of lung cancer will mean that a higher proportion of cases are diagnosed when the tumor is still resectable and are candidates for treatment with osimertinib.
