“Exciting” Results in Study of EGFR-Targeting Drug

• Nancy Meredith
• Featured News

In November, Mesothelioma Help reported the U.S. Food and Drug Administration granted accelerated approval for the anti-cancer drug Tagrisso (osimertinib) for lung cancer. This approval opened the door for another mesothelioma treatment as well. Now, researchers report exciting results from a study looking at osimertinib as first-line therapy for epidermal growth factor receptor (EGFR) mutation positive lung cancer patients.

The news of this drug is exciting for several reasons, but primarily for the fact that it demonstrated progression-free survival in first-line therapy. Typically, nearly 50 to 60% of lung cancer patients who experience disease progression after being treated with an EGFR inhibitor often develop the T790M resistance mutation. However, many of the patients in the study “have not had disease progression on the study and are still benefitting from treatment,” according to the researchers.

“The overall response rate was among the best reported for first-line therapy of EGFR-mutated NSCLC,” said Suresh Ramalingam, MD, professor of hematology and medical oncology at Emory School of Medicine and deputy director of the Winship Cancer Institute in Atlanta, in an April 15 press release announcing the findings. “The progression-free survival results are exciting, well exceeding the historical control rates of 10 to 13 months with first- or second-generation drugs.”

In the study of 60 patients with EGFR mutatated non-small cell lung cancer, who received osimertinib without having undergone any other treatment, the overall response rate was 77%. In addition, the patients who did have disease progression did not have T790M mutation, leading Ramalingam to suggest the drug is “changing the biology of the disease.”

In a second study, patients realized nearly the same response rate, 71% in this study, in EGFR-mutated/T790M positive lung cancer patients who had progressed on previous EGFR TKI therapy.

EGFR is a protein found on the surface of some cells to which epidermal growth factor binds, which causes the cells to divide and spread. According to a 2009 article in Current Drug Targets, EGFR overexpression has been shown in more than 50% of pleural mesothelioma patients, and approximately 15% of patients with lung cancer in the U.S. express EGFR mutations. T790M is a genetic mutation responsible for EGFR-TKI treatment resistance. Osimertinib inhibits both EGFR and T790M, according to AstraZeneca, the maker of the drug.

Next, researchers will conduct a phase III clinical trial with approximately 500 patients comparing osimertinib to either erlotinib or gefitinib for front-line therapy. Erlotinib and gefitinib are kinase inhibitors used to treat mesothelioma and lung cancer. According to the press release, results are expected within 18 months.

The information was presented by Suresh Ramalingam, MD, professor of hematology and medical oncology at Emory School of Medicine and deputy director of the Winship Cancer Institute in Atlanta, at the European Lung Cancer Conference 2016 in Geneva.

http://www.esmo.org/Conferences/Past-Conferences/ELCC-2016-Lung-Cancer/News-Press-Releases/Osimertinib-Given-as-First-line-Treatment-May-Alter-Biology-of-EGFR-Mutated-Non-Small-Cell-Lung-Cancer