Osimertinib as Adjuvant Therapy in EGFR-Mutant Lung Cancer

Mark G. Kris, MD


October 16, 2020

This transcript has been edited for clarity.

Hello. This is Mark Kris from Memorial Sloan Kettering Cancer Center, speaking about more data that have come out about the use of osimertinib as an adjuvant therapy after a complete resection for patients with EGFR-mutant lung cancers.

I think all of us were extremely excited to see the data from the ASCO meeting at the plenary session showing that osimertinib, compared with placebo, dramatically improved the disease-free survival of patients who received it in the adjuvant setting after chemotherapy. There was a 36% improvement in the proportion of patients who were disease-free at 2 years by adding osimertinib, which is an astounding result. The drug was, by and large, well tolerated.

It makes sense to want to use this drug going forward. I hope things are moving along to get this drug approved in this setting.

Along the way, we have data from the original presentation now published in The New England Journal of Medicine by Dr Wu and colleagues.

And at this year's virtual European Society for Medical Oncology (ESMO) meeting, Dr Tsuboi talked about patterns of recurrence and progression in patients on this trial. There were 37 patients on osimertinib who had a progression event vs 157 patients in the placebo arm, which is an astounding number of patients being freed from progression by the use of this very reasonable and tolerable agent. These data reinforce what we saw in the original paper presented at ASCO: that it's an important development for patients in improving progression-free survival.

The other interesting thing is that they now have data as to the site of progression. Overall, 11% of patients in the osimertinib arm and 46% of patients in the placebo arm experienced recurrence. In those patients, the majority of progression events occurred in the lung or in the lymph nodes. That's not what you usually see when patients recur after a complete resection for early-stage lung cancer. However, that's what they saw, and that needs to be adjudicated.

The one other interesting fact was the number of recurrences in the central nervous system (CNS). Of the 11% of patients with recurrence in the osimertinib arm, only 1% had metastasis in the CNS compared with 10% in the placebo arm. It is not only that osimertinib can prevent recurrence but also that it appears to prevent recurrence in the CNS, which is a devastating site.

These additional data presented at ESMO demonstrate that osimertinib is an important drug in the adjuvant setting for patients with completely resected EGFR-mutant lung cancers.

Also, just a reminder that these patients, in addition to having a successful complete resection, had postoperative chemotherapy whenever stage-appropriate. Chemotherapy has been shown to improve the cure rate. The information available to us today shows that chemotherapy needs to be given first, and osimertinib should be considered an adjunct to the chemotherapy as a systemic therapy.

We have more good news on osimertinib in the adjuvant setting. We are making an important impact on our patients' lives by giving this drug and preventing symptomatic progression and devastating progression in the CNS. Hopefully this drug marches toward an approval and widespread use.

Mark G. Kris, MD, is chief of the thoracic oncology service and the William and Joy Ruane Chair in Thoracic Oncology at Memorial Sloan Kettering Cancer Center in New York City. His research interests include targeted therapies for lung cancer, multimodality therapy, the development of new anticancer drugs, and symptom management with a focus on preventing emesis.

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