Abstract CT170: D-0316 in patients with advanced T790M-positive EGFR-mutant non-small cell lung cancer who progressed on prior EGFR-TKI therapy: results from a phase II study (NCT03861156)

D-0316 in patients with advanced T790M-positive EGFR-mutant non-small cell lung cancer who progressed on prior EGFR-TKI therapy: results from a phase II study (NCT03861156) Background: Despite initial response to EGFR-TKI, most patients (pts) develop resistance with the EGFR T790M mutation detectable in ~50% of patients treated with first-/second-generation EGFR-TKIs. D-0316 is a third-generation EGFR-TKI that is selective for both EGFR-TKI sensitizing and T790M resistance mutations in pts with non-small cell lung cancer (NSCLC). We report the results of a registered, single-arm, phase II study of D-0316 in NSCLC pts with EGFR T790M who progressed on previous treatment with first-line EGFR-TKIs. Methods: In this phase II, open-label, single-arm study, eligible pts were those who had confirmed locally advanced or metastatic NSCLC, and had disease progression after first-line EGFR-TKI and with T790M mutation. Pts were initially orally given D-0316 50 mg. However, considering the benefits and risks of the pts, the dose was modified to 100 mg once daily with a 21-day lead-in at 75 mg once daily. The primary endpoint was objective response rate (ORR) based on independent review committee (IRC) according to RECIST 1.1.Results: As of October 31, 2019, 176 pts were enrolled in the 50 mg phase, in which 90 pts had partial response, achieving an ORR of 51.1% (95%CI: 43.5-58.7). Despite the immature PFS, disease progression or death occurred in 60 pts (34.1%) and the median PFS was 8.4 months (95% CI: 8.0-NE). Between September 12, 2019 and July 29, 2020, 689 pts were screened and 290 pts (median age 62.5) were enrolled in China and received 100mg D-0316 with a 21-day lead-in at 75 mg. At data cutoff (October 18, 2020), the median duration of follow-up was 5.5 months. 188 of the 290 pts achieved confirmed partial responses by IRC. The ORR was 64.8% (95% CI: 59.0-70.3) and the disease control rate (DCR) was 95.2% (95% CI: 92.0-97.3). The ORR was consistent across in most subgroups. Among 34 pts with brain metastases at baseline, 18 pts achieved confirmed partial responses and the intracranial ORR was 52.9% (95% CI: 35.1-70.2). The PFS, DoR, and OS were premature. The most common treatment-related adverse events were thrombocytopenia (57.2%), headache (27.6%), leukopenia (23.4%), anemia (22.1%) and rash (20.7%). The most common grade 3 or higher treatment-related adverse events were thrombocytopenia (11.7%). One death was due to treatment-related adverse events (interstitial lung disease). Six interstitial lung diseases (2.1%) were observed during study treatment. Conclusion: D-0316 has showed strong anti-tumor activities and tolerable toxicity in pts with EGFR T790M-positive NSCLC who have progressed after EGFR-TKI treatment. Citation Format: Shun Lu, Yiping Zhang, Guojun Zhang, Jianying Zhou, Shundong Cang, Ying Cheng, Gang Wu, Peiguo Cao, Dongqing Lv, Xiangming Jin, Hong Jian, Chengshui Chen, Guanming Jiang, Panwen Tian, Kai Wang, Hui Zhao, Gongyan Chen, Qun Chen, Cuimin Ding, Junquan Yang, Renhua Guo, Guoping Sun, Bin Wang, Liyan Jiang, Wu Zhuang, Zhe Liu, Jian Fang, Yunpeng Liu, Jian Zhang, Jun Chen, Yueyin Pan, Qitao Yu, Min Zhao, Jiuwei Cui, Dianming Li, Tienan Yi, Zhuang Yu, Yan Yang, Yan Zhang, Xiuyi Zhi, Yunchao Huang, Rong Wu, Liangan Chen, Aimin Zang, Lejie Cao, Qingshan Li, Xiaoling Li, Yong Song, Donglin Wang, Shucai Zhang. D-0316 in patients with advanced T790M-positive EGFR-mutant non-small cell lung cancer who progressed on prior EGFR-TKI therapy: results from a phase II study (NCT03861156) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT170.