Osimertinib is a molecularly targeted agent used to treat non-small cell lung cancer (NSCLC) patients with an epidermal growth factor receptor (EGFR) T790M mutation. However, its efficacy and safety profile when patients have poor performance status (PS) is unknown. Therefore, we conducted an open-label, multi-center, single-arm phase II study to evaluate its efficacy and safety in EGFR T790M mutation-positive NSCLC patients with Eastern Cooperative Oncology Group PS scores of between 2 and 4. Patients received 80 mg of osimertinib once daily. Our primary endpoint was progression-free survival. Eighteen patients were enrolled between June 2017 and November 2018. The median age was 77 years (range: 55-85 years). Ten, six, and two patients had PS scores of 2, 3, and 4, respectively. All patients had adenocarcinoma with common EGFR mutations and had been treated with first- or second-generation EGFR- tyrosine kinase inhibitors previously. The overall median progression-free survival was 7.0 months (90% confidence interval: 5.5-8.9 months). The overall response rate and median overall survival were 53% and 12.7 months, respectively. Moreover, improved PS scores were observed in 72% of the patients. Although the incidence of grade 3 adverse events was low, with no grade 4 or 5 events observed, three patients required treatment cessation due to the development of interstitial lung disease. Osimertinib therapy could be beneficial for EGFR T790M mutation-positive advanced NSCLC patients with poor PS. This trial was registered with the Japan Registry of Clinical Trials on March 12, 2019 (trial no. jRCT1041180081).

中文翻译：

---

奥希替尼用于体能状态不佳和 EGFR T790M 突变阳性晚期非小细胞肺癌患者：一项 II 期临床试验。

奥希替尼是一种分子靶向药物，用于治疗具有表皮生长因子受体 (EGFR) T790M 突变的非小细胞肺癌 (NSCLC) 患者。然而，其在体能状态 (PS) 较差的患者中的疗效和安全性尚不清楚。因此，我们进行了一项开放标签、多中心、单组 II 期研究，以评估其在 EGFR T790M 突变阳性 NSCLC 患者中的疗效和安全性，东部肿瘤协作组 PS 评分介于 2 和 4 之间。患者接受 80 mg奥希替尼每天一次。我们的主要终点是无进展生存期。2017 年 6 月至 2018 年 11 月期间招募了 18 名患者。中位年龄为 77 岁（范围：55-85 岁）。十名、六名和两名患者的 PS 评分分别为 2、3 和 4。所有患者均患有具有常见 EGFR 突变的腺癌，并且之前曾接受过第一代或第二代 EGFR-酪氨酸激酶抑制剂治疗。总体中位无进展生存期为 7.0 个月（90% 置信区间：5.5-8.9 个月）。总反应率和中位总生存期分别为 53% 和 12.7 个月。此外，在 72% 的患者中观察到 PS 评分有所改善。尽管 3 级不良事件的发生率很低，没有观察到 4 级或 5 级事件，但 3 名患者因间质性肺病的发展而需要停止治疗。奥希替尼治疗可能对 PS 差的 EGFR T790M 突变阳性晚期 NSCLC 患者有益。该试验于 2019 年 3 月 12 日在日本临床试验注册中心注册（试验编号 jRCT1041180081）。