Amaria Rodabe N, Kim Kevin B
The University of Texas MD Anderson Cancer Center, Department of Melanoma Medical Oncology , Unit 430, 1515 Holcombe Blvd, Houston, TX 77030 , USA.
Expert Opin Pharmacother. 2014 May;15(7):1043-50. doi: 10.1517/14656566.2014.909410. Epub 2014 Apr 10.
Approximately 50% of patients with cutaneous melanoma have an activating mutation in BRAF kinase, leading to constitutive activation of the mitogen-activated protein kinase pathway and unregulated cell growth. Selective inhibitors of the mutated BRAF kinase produce response rates of approximately 50% with median progression-free survival of 6 - 7 months. BRAF-blocking therapies work rapidly, with responses seen within 2 weeks after therapy initiation, and they are associated with generally mild toxicities. The BRAF inhibitor dabrafenib recently was approved for use in patients with BRAF V600-mutated metastatic melanoma.
This article discusses the mechanisms of action and pharmacokinetic and pharmacodynamic changes as well as clinical efficacy and safety of dabrafenib for treatment of patients with advanced melanoma including unresectable stage IIIc and stage IV patients who harbor a BRAF V600 mutation. Clinical trial data are reviewed, and efficacy of dabrafenib in patients with brain metastases and in combination with the MEK inhibitor trametinib is discussed.
Despite rapid and significant tumor reduction in a majority of patients with BRAF-mutant metastatic melanoma who are treated with dabrafenib, this drug's use as a single agent is limited because of its relatively short duration of response. Various combinations with drug(s) inhibiting other target kinases and/or with immunomodulating agent(s) will likely be the standard in the near future.
约50%的皮肤黑色素瘤患者存在BRAF激酶激活突变,导致丝裂原活化蛋白激酶途径的组成性激活及细胞生长失控。突变型BRAF激酶的选择性抑制剂产生的缓解率约为50%,中位无进展生存期为6至7个月。BRAF阻断疗法起效迅速,在治疗开始后2周内即可观察到疗效,且通常毒性较轻。BRAF抑制剂达拉非尼最近被批准用于治疗BRAF V600突变的转移性黑色素瘤患者。
本文讨论了达拉非尼治疗晚期黑色素瘤患者(包括不可切除的IIIc期和IV期且携带BRAF V600突变的患者)的作用机制、药代动力学和药效学变化以及临床疗效和安全性。回顾了临床试验数据,并讨论了达拉非尼在脑转移患者中以及与MEK抑制剂曲美替尼联合使用时的疗效。
尽管大多数接受达拉非尼治疗的BRAF突变转移性黑色素瘤患者肿瘤迅速且显著缩小,但由于其缓解持续时间相对较短,该药物作为单一药物的应用受到限制。在不久的将来,与抑制其他靶激酶的药物和/或免疫调节剂的各种联合用药可能会成为标准治疗方案。