By: Dr. Anish Shah
Bronx-Lebanon Hospital; Bronx, NY
The FDA gave its approval for the use of osimertinib (Tagrisso, AstraZeneca Pharmaceuticals LP) alongside platinum-based chemotherapy for patients with locally advanced or metastatic non-small cell lung cancer (la/mNSCLC) on February 16, 2024. This approval applies to patients whose tumors exhibit EGFR exon 19 deletions or exon 21 L858R mutations, as identified by an FDA-sanctioned test.
Study ID: NCT04035486
The approval was based on the FLAURA 2 trial, an open-label, randomized study of 557 patients. The patients, all with EGFR exon 19 deletion or exon 21 L858R mutation-positive la/mNSCLC, had not undergone prior systemic therapy for advanced disease. They were equally divided to receive either osimertinib with platinum-based chemotherapy or osimertinib as a standalone treatment. The suggested dosage for osimertinib is 80 mg, to be taken orally once daily, with or without food, until the disease progresses, or the toxicity becomes unacceptable.
The primary measure of efficacy was progression free survival (PFS), with overall survival (OS) as an important secondary measure. The combination of osimertinib and platinum-based chemotherapy showed a statistically significant increase in PFS compared to osimertinib alone, with a hazard ratio of 0.62 (95% Confidence Interval [CI]: 0.49, 0.79; two-sided p value<0.0001). The median PFS was 25.5 months (95% CI: 24.7, NE) and 16.7 months (95% CI: 14.1, 21.3) for the combined and standalone groups, respectively. Although the OS results are not yet fully mature, with 45% of the predetermined deaths for the final analysis reported, there was no indication of a negative impact.
The most frequently observed side effects (≥ 20% incidence) in patients receiving the combined treatment of osimertinib and platinum-based chemotherapy included leukopenia, thrombocytopenia, neutropenia, lymphopenia, rash, diarrhea, stomatitis, nail toxicity, dry skin, and an increase in blood creatinine.
