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http://www.asco.org/ASCOv2/Meeti ... mp;abstractID=95393
Abstract:
Background: Dysregulation of MET and VEGF signaling has been implicated in breast cancer development and progression, including tumor invasion and dissemination. Cabozantinib (cabo) is an oral, potent inhibitor of MET and VEGFR2. A RDT evaluated activity and safety in 9 tumor types, including MBC.
Methods: Eligible patients (pts) were required to have progressive measurable disease per RECIST. Pts received cabo at 100 mg qd over a 12 wk Lead-in stage. Tumor response (mRECIST) was assessed q6 wks. Treatment ≥ wk 12 was based on response: pts with PR continued open-label cabo, pts with SD were randomized to cabo vs placebo, and pts with PD discontinued. Primary endpoint in the randomized discontinuation phase was progression-free survival (PFS).
Results: Enrollment to this cohort is complete (n = 45); all pts are unblinded. Baseline characteristics: median age 56; invasive ductal 86%, invasive lobular 7%; ER+ 93%, HER2+ 18%, triple- 5%; visceral disease 91%; bone metastases 73%; median prior lines of therapy 3 (range 1-8), including 71% with prior anthracyclines. Median follow-up was 2.9 mos (range 0.1 -16). 21 pts (47%) completed Lead-in stage with only 9 randomized to continue cabo (n = 5) or placebo (n = 4). Median PFS from Study Day 1 was 4.1 mos. At wk 12, objective response rate was 14% and disease control rate 48%. Tumor regression was observed in 25/39 pts (64%) with ≥1 post-baseline tumor assessment. 4/10 pts evaluable by bone scan had partial resolution of bone lesions. Of 12 pts receiving narcotics for bone pain, 5 pts reported improved pain and 2 pts had decreased narcotics use, per investigator. 4/14 evaluable pts (29%) with bone metastases experienced ≥50% decline in serum NTx. Most common Grade 3/4 AEs were palmar-plantar erythrodyesthesia (13%) and fatigue (11%). One related Grade 5 AE of respiratory compromise was reported during the Lead-in stage. Conclusions: Cabo demonstrated a 14% rate of objective tumor regression in heavily pretreated MBC pts. Observed effects on bone scan and pain are consistent with those seen in other malignancies. The safety profile of cabo was comparable to that seen with other VEGFR TKIs.
实验方法是这样的,45个病人每天口服100mgXL184,6周后PR的病人继续口服XL184,SD的病人则随机分为XL184和安慰剂。
6周后,21(47%)个病人继续实验,其中9个接受随机安慰剂对照实验,5个XL184,4个安慰剂。
在第12周,客观反应率在14%,疾病控制率48%。
XL184对改善骨痛有帮助。25/39的病人观察的肿瘤消退。
3、4级毒性主要是严重手足反应(13%)和乏力(11%)。
XL184是一种口服的cmet、VEGFR2双重抑制剂。统计表明cMET过表达与乳腺癌淋巴转移有关,也促进血管生成。 |
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