Osimertinib’s Success in Lung Cancer Treatment Made Its Mark at ESMO 2017

One of the new-generation targeted treatments, used for EGFR-mutant (exon 19 deletion, L858R mutation) lung cancers, Osimertinib was compared with Gefitinib, introduced in 2003, and Erlotinib, approved by the FDA in 2004, in the randomized phase 3 FLAURA study, which included both of these important drugs defined as standard treatment.

Osimertinib is a new-generation tyrosine kinase inhibitor acting on a type of growth receptor found in lung cancer cells, blocking the growth signal it sends inside the cell. In routine practice, we used it in patients who had taken Gefitinib and Erlotinib, experienced progression and had a detected T790M mutation. Successful preliminary study results provided evidence that it might be used as a first option in EGFR-mutant patients, leading to the design of FLAURA, whose preliminary results were shared at the ESMO 2017 European Oncology Congress.

The study included 556 patients, with one group (279 patients) receiving Osimertinib (Tagrisso) and the other (275 patients) receiving Gefitinib (Iressa) or Erlotinib (Tarceva). Median time to lung cancer progression was 19 months with Osimertinib and 10 months in the standard treatment arm, a statistically significant result. Treatment response rates were % 80 versus % 76; among responding patients, median response duration was 17.2 months with Osimertinib versus 8.5 months in the Gefitinib and Erlotinib arm. A significant increase in benefit was also found in patients with brain metastasis , demonstrating superior penetration into the brain.

The study found that the duration of treatment benefit with Osimertinib was almost twice as long, a result medical authorities also considered exciting.

We await publication of the study, whose comparative long-term survival results are not yet known. It appears that the successful Osimertinib treatment results in FLAURA will displace Gefitinib and Erlotinib as first-choice treatment in EGFR mutation-positive patients.

In patients with stage 4 metastatic lung cancer, especially those suitable for targeted treatment, this success appears likely to shift the target for expected survival from 2 years to 3 years. This substantial increase from survival of around one year with chemotherapy is extremely encouraging. In this patient group, when progression is detected after targeted therapies, the use of immunotherapies may extend this period further. Advances in modern oncology treatments have accelerated in recent years. Lung cancer treatment is one of these areas.

In our next article, we will share the new treatment success announced at ESMO 2017 in BRAF-mutant lung cancer patients.