In the first presidential symposium at the European Society for Medical Oncology (ESMO) 2017 Congress in Madrid, Spain, AstraZeneca unveiled full results of the Phase III FLAURA trial. FLAURA is evaluating Tagrisso (osimertinib) in the first line treatment of adult patients with locally-advanced or metastatic non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations.
FLAURA evaluated the efficacy and safety of Tagrisso taken 80mg orally and once daily against the standard-of-care (SOC) EGFR tyrosine kinase inhibitors (TKI), which comprised either Roche’s Tarceva (erlotinib) at 150mg orally, once daily, or AstraZeneca’s Iressa (gefitinib) at 250mg orally, once daily. The trial involved previously untreated patients with locally advanced or metastatic EGFR mutation-positive NSCLC. The trial was a double-blinded, randomised study, with 556 patients.
The primary endpoint of the trial was progression free survival (PFS), with secondary endpoints including overall survival (OS), objective response rate (ORR), duration of response (DOR), safety, and measures of health-related quality of life.
The data presented from the FLAURA trial could encourage front line uptake of Tagrisso, particularly in the subset of patients with CNS metastases. A superior PFS was observed with Tagrisso with 18.9 months compared to 10.2 months with Iressa or Tarceva. Risk of progression was cut by 54%, a statistically significant result. In addition, the improvement in PFS was consistent across all pre-specified subgroup analyses, with a minimum of 40% reduction in the risk of disease worsening or death with Tagrisso treatment, including in patients with or without central nervous system (CNS) metastases at the time of study enrollment, patients with or without prior smoking history, and patients with Exon 19 deletion or L858R sensitising mutations.
Interim OS data (at 25% maturity) was clinically meaningful. The hazard ratio for OS was in favour of Tagrisso at 0.63. However, the p-value of 0.0068 was not below the threshold of 0.0015 required for statistical significance at the current level of maturity.
Given the current uncertainty of OS improvement over the SOC, if the final OS data is expected to give more definitive evidence of the benefit of Tagrisso in the first line setting. The median DOR was more than double in patients treated with Tagrisso than those on the comparator arm group (17.2 months versus 8.5 months), and an ORR of 80% versus 76% with the comparator arm group. The early and sustained benefit observed with Tagrisso has the potential to improve long-term patient outcomes.
In terms of safety, patients treated with Tagrisso experienced lower rates of Grade 3 or higher treatment related adverse events versus the comparator arm (33.7% versus 44.8%), and lower rates of adverse events leading to discontinuation (44.8% versus 13.3%).
Tagrisso is currently restricted to patients with an abnormal T790M gene, after progression on an EGFR TKI therapy. If Tagrisso is approved in the front-line setting of EGFR-mutated NSCLC, it would advance into earlier lines of treatment and expand its eligible patient pool. In patients with CNS metastasis, the benefit of Tagrisso was quite impressive and there was sufficient evidence to support its frontline use for this subset of patients. Compared with first / second generation TKIs, the subgroup of patients that are EGFR mutation positive may attain long duration of PFS. However, the optimal drug sequencing of TKIs to maximise the overall OS benefit for these patients remains unclear and is pending on final OS data from the FLAURA trial.
GlobalData (2016). PharmaPoint: Non-Small Cell Lung Cancer (NSCLC) – Global Drug Forecast and Market Analysis to 2025, November 2016, GDHC134PIDR