Trial results for the Phase 2 study (NCT05215951) investigating osimertinib plus chemotherapy as first-line treatment for recurrent, locally advanced, or metastatic non-small cell lung cancer (NSCLC) patients with uncommon epidermal growth factor receptor mutations (EGFRm) were posted on ClinicalTrials.gov on 2025-10-15. The single-arm study reported an objective response rate (ORR) of 75.0% and a disease control rate (DCR) of 100%.
Background
Osimertinib (Tagrisso) is an approved therapy for certain types of non-small cell lung cancer. This particular study investigated its use in combination with standard chemotherapy (Platinum plus Pemetrexed) as a first-line treatment for recurrent, locally advanced, or metastatic NSCLC in patients specifically harboring uncommon epidermal growth factor receptor mutations (EGFRm).
Trial design
The Phase 2 study (NCT05215951) was an open-label, single-arm, multicenter, exploratory trial sponsored by Astrazeneca Investment (China) Co., LTD. It enrolled 4 participants with recurrent, locally advanced, or metastatic non-small cell lung cancer (NSCLC) with uncommon epidermal growth factor receptor mutations (EGFRm). The study evaluated osimertinib in combination with Platinum plus Pemetrexed Chemotherapy as a first-line treatment. The trial was terminated.
Key results
The trial reported several key efficacy measurements for the osimertinib plus standard chemotherapy single-arm group:
- The objective response rate (ORR) was 75.0% (Percentage of Patients).
- The disease control rate (DCR) was 100% (Percentage of patients).
- The median depth of response, measured as the best absolute change in target lesion tumor size from baseline, was 47.50 mm.
- The median depth of response, measured as the best percentage change in target lesion tumor size from baseline, was 53.61%.
Median values for Progression-Free Survival (PFS), Overall Survival (OS), Duration of Response (DoR), Time to Treatment Failure (TTF), and Time to First Subsequent Therapy (TFST) were reported as 'NA' in the study data.
What this means
The results from this exploratory Phase 2 study suggest that osimertinib in combination with chemotherapy may demonstrate clinical activity in patients with uncommon EGFRm NSCLC, as indicated by the 75.0% objective response rate and 100% disease control rate. However, the trial was terminated and had a very small enrollment of only 4 participants, which limits the generalizability and statistical power of these findings. While the depth of response measurements also indicate tumor shrinkage, these early-phase, single-arm results require further investigation in larger, controlled studies to confirm efficacy and safety.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT05215951, titled 'Osimertinib Plus Chemotherapy in Uncommon EGFRm NSCLC,' were posted on 2025-10-15 on clinicaltrials.gov.