Phase II clinical study of SRS combined with osimertinib in the treatment of EGFR positive non-small cell lung cancer with brain metastasis

Abstract Objective To observe the safety and efficacy of SRS synchronous osimertinib compared with osimertinib alone in the treatment of patients with brain metastasis of EGFR positive non-small cell lung cancer. Methods Select the EGFR positive non-small cell lung cancer patients with brain metastasis admitted to our hospital from January 2018 to January 2020. The experimental group: 30 patients were treated with SRS combined with osimertinib. SRS treatment: prescription dose (d = 0-40mm, 27Gy/3f); Targeted treatment scheme: osimertinib, 80mg/day, taken orally after SRS treatment; Control group: 30 patients were treated with osimertinib alone; osimertinib was maintained until disease progression (PD) or adverse reactions were intolerable. PFS, ORR, DCR and AEs of intracranial lesions were observed. Results This study plans to include 60 patients, with a median age of 54.8 (35–79) years, including 41 males and 19 females, with a median follow-up time of 34.5 (30–42) months; There were 30 cases in the experimental group and 30 cases in the control group, respectively. The ORR of intracranial lesions in the two groups were 96.67% and 66.67% respectively, with significant statistical difference between the two groups (p = 0.003); The DCR of intracranial lesions were 100% and 96.67% respectively, and there was no significant difference between the two groups (p = 0.313); The median PFS of intracranial lesions were 26.5 months and 16.5 months, respectively. There was a significant difference between the two groups (p < 0.001); The most common adverse event of radiotherapy was radioactive brain edema. The incidence of grade Ⅰ - Ⅱ in the experimental group was 43.33%. After treatment of intracranial pressure reduction, it improved, and no grade Ⅲ - Ⅳ radioactive brain edema occurred; The second adverse event was osimertinib Ⅰ - Ⅱ, mainly including diarrhea, rash, oral ulcer, etc. Conclusions SRS synchronous osimertinib therapy is more effective than simple osimertinib in the treatment of brain metastasis of EGFR positive non-small cell lung cancer patients, and the side effects are tolerable. We look forward to further large phase III clinical studies to confirm it. Trial Registration This study was registered with China Clinical Trial Registration Center (www.chictr.org.cn, identifier:ChiCTR1900025626,Reg Date:2019/09/03)