The control arms (chemotherapy alone) in two major, independent trials, Mariposa 2 and Harmony, both yielded an identical median progression-free survival of 4.4 months. This consistency across studies validates the data and strengthens the conclusion that chemotherapy alone is a poor benchmark post-TKI failure.

The COMPEL study showed a near doubling of progression-free survival by continuing osimertinib with chemotherapy after first-line progression. This contradicts findings with first-generation TKIs (like gefitinib) and establishes "TKI continuation" as a new standard of care.

The LAURA trial shows a favorable overall survival trend for osimertinib consolidation even though 80% of placebo patients received osimertinib upon progression. This high crossover rate makes the persistent trend highly significant, suggesting a strong benefit to earlier TKI administration.

The NeoADURA trial demonstrates that adding osimertinib in the neoadjuvant setting for EGFR-mutated NSCLC results in a 'humongous benefit' in major pathological response and nodal downstaging compared to chemotherapy alone, significantly improving surgical outcomes.

The FLORA two study's overall survival benefit was so compelling that clinicians should now default to osimertinib plus chemotherapy for most first-line EGFR-mutant NSCLC patients, only opting out for specific reasons like comorbidities or patient preference.

Due to a 10-11 month overall survival benefit shown in the FLORA two regimen, leading oncologists now consider osimertinib plus chemotherapy the standard first-line treatment for metastatic EGFR-mutant NSCLC. Monotherapy is reserved only for patients who cannot tolerate or refuse chemotherapy.

When EGFR+ NSCLC transforms to small cell, clinicians often continue the TKI osimertinib alongside chemotherapy. This practice is largely based on expert consensus and the rationale of suppressing any remaining EGFR-driven clones, rather than on definitive clinical trial data showing a clear benefit.

While research pursues mechanism-based strategies (e.g., 4th-gen TKIs) for acquired resistance, recent practical breakthroughs are mechanism-agnostic, like ADCs or chemotherapy combinations. This highlights a pragmatic, broad-spectrum approach to treating progression after frontline osimertinib.

Unlike immunotherapy, neoadjuvant osimertinib yields poor pathologic complete response (pCR) rates. However, it significantly improves major pathologic response (MPR) and survival, suggesting pCR may be the wrong efficacy endpoint for cytostatic EGFR TKIs, which have a different mechanism of action than immunotherapy.