文章来源：医脉通

2015年ASCO年会将于5月29日--6月2日在美国芝加哥召开，5月31日上午的非小细胞肺癌（NSCLC）口头报告专场，将公布ECOG-ACRIN癌症研究组的一项随机2期试验（E1512），探讨卡博替尼（C）、厄洛替尼（E）或者两药联合（E+C）用于EGFR野生型（wt）NSCLC患者二线或三线治疗的疗效。摘要结论指出，对于EGFR野生型NSCLC患者，卡博替尼、卡博替尼+厄洛替尼相比厄洛替尼单药更改善PFS。

背景：卡博替尼是一种多受体酪氨酸激酶小分子抑制剂，包括MET、VEGFR2和RET。MET参与肿瘤分化，VEGFR2参与血管生成的调节。厄洛替尼已获FDA批准治疗NSCLC。

方法：该随机II期研究的主要目的是对比E vs C，E vs E+C治疗患者的无进展生存期（PFS），每种比较都有91%的效能检测出0.5的PFS风险比（HR），单侧检验水平为0.10，且根据既往治疗次数和ECOG PS进行分层。次要终点包括总生存期（OS），RECIST 1.1缓解以及CTCAE v4毒性。患者为既往接受过治疗（1-2种方案）的转移性非鳞癌EGFR野生型NSCLC患者。要求提供档案组织进行中央MET IHC检测。

每日给药剂量为：E-150mg；C-60mg；E+C-150mg E，40mg C。每8周做一次影像学检查。E或C治疗后疾病进展可随意交叉换至E+C方案。

结果：125名患者被纳入，其中115名符合标准（E，n=39；C，n=39；E+C，n=37）。除了E组有更低的脑转移率（p=0.02）外，其余的患者特征在各组间是平衡的。中位随访8.5个月。与E组1.9个月PFS相比，C组的PFS明显增加（3.9个月，HR 0.33，p=0.0002,80%CI，0.22-0.49），E+C组也明显增加（4.1个月，HR 0.31，p=0.0002,80%CI，0.21-0.46）。

OS也类似，与E组的4.0个月相比，C组（HR 0.52，p=0.02）和E+C组（HR 0.50，p=0.02）的OS都明显升高。C组的3-4级治疗相关高血压和粘膜炎发生率更高，E+C组的3-4级腹泻发生率更高。C组和E+C组整体的高级别毒性发生率明显较高。

88名患者的MET IHC结果可获知，其中85%是阳性（膜或胞浆MET4抗体染色是1-3个加号）。MET状态和PFS无相关性。

结论：对于EGFR野生型NSCLC患者，卡博替尼、卡博替尼+厄洛替尼相比厄洛替尼单药更改善PFS。卡博替尼为基础的方案对于这一患者群是未来值得研究的方案。

会议专题》》》2015年ASCO年会专题报道

阅读摘要原文

Cabozantinib (C), erlotinib (E) or the combination (E+C) as second- or third-line therapy in patients with EGFR wild-type (wt) non-small cell lung cancer (NSCLC): A randomized phase 2 trial of the ECOG-ACRIN Cancer Research Group (E1512).(Abstract No:8003)

Author(s): Joel W. Neal, Suzanne Eleanor Dahlberg, Heather A. Wakelee, et al

Type: Oral Abstract Session

Background: Cabozantinib (C) is a small molecule inhibitor of multiple receptor tyrosine kinases, including MET, VEGFR2 & RET. MET is involved in tumor differentiation & VEGFR2 is a mediator of angiogenesis. Erlotinib (E) is FDA approved for the treatment of NSCLC.

Methods: The primary objective of this randomized phase II study was to compare progression-free survival (PFS) of patients (pts) treated with E vs. C, & E vs E+C; each comparison had 91% power to detect a PFS hazard ratio (HR) of 0.5 with a 1-sided 0.10-level test stratified on prior number of therapies & ECOG PS. Secondary objectives included overall survival (OS), RECIST 1.1 response & CTCAE v4 toxicity. Pts were selected with previously treated (1-2 regimens) metastatic non-squamous EGFR wt NSCLC. Submission of archival tissue for central MET IHC testing was required. Oral daily dosing was: E-150 mg; C-60 mg; E+C-150 mg E, 40 mg C. Imaging was performed every 8 weeks. Pts optionally crossed over to E+C following progression on E or C.

Results: One hundred and twenty-five pts were enrolled, of which 115 were eligible and treated (E, n = 39; C, n = 39; E+C, n = 37). Pt characteristics were balanced between arms except for lower rate of brain mets history on E (p = 0.02). Median follow up is 8.5 m. Compared with E (median 1.9 m), PFS was significantly improved on C (3.9 m, HR 0.33, p = 0.0002, 80% CI 0.22-0.49) and E+C (4.1 m, HR 0.31, p = 0.0002, 80% CI 0.21-0.46). Similarly, compared with E (median 4.0 m), OS was significantly improved on C (HR 0.52, p = 0.02) and E+C arm HR 0.50, p = 0.02). Grade 3-4 treatment-related hypertension & mucositis were higher on C and grade 3-4 diarrhea was higher on E+C. Overall worst grade toxicities were also significantly higher on C and E+C. MET IHC results were available on 88 patients from the primary analysis & 85% were positive (1-3+ membrane or cytoplasm staining with MET4 antibody). There was no correlation between MET status and PFS.

Conclusions: C & C+E significantly improved PFS over E alone in pts with EGFR wt NSCLC. Cabozantinib-based regimens are promising for further investigation in this patient population. Funded by ECOG-ACRIN and NCI Contract No. HHSN261200800001E. Clinical trial information: NCT01708954