Xtandi获准用于特定的转移性前列腺癌患者

圣路易斯(MD Consult)——美国食品药品管理局(FDA)和安斯泰来制药公司宣布，Xtandi(enzalutamide)已获准用于曾接受多西他赛治疗的转移性去势耐药性前列腺癌的治疗。Xtand是一种每日口服1次的雄激素受体抑制剂。

Xtandi的疗效和安全性已在一项随机、安慰剂对照的多中心3期临床试验中得到了评估。这项试验招募了1,199例曾接受多西他赛治疗的转移性去势耐药性前列腺癌患者，旨在评价接受Xtandi治疗者与安慰剂组患者的总生存率。结果显示，Xtandi组患者的中位生存期为18.4个月，而安慰剂组患者仅为13.6个月。

在临床研究中，患者最常发生的不良反应为虚弱/疲乏、背痛、腹泻、关节痛、潮热、外周水肿、肌肉骨骼痛、头痛、上呼吸道感染、肌无力、头晕、失眠、下呼吸道感染、脊髓压缩和马尾综合征、血尿、感觉异常、焦虑以及高血压。Xtandi组患者47%发生≥3级不良反应，这一比例在安慰剂组为53%。

在这项随机临床试验中，0.9%的Xtandi组患者曾出现癫痫样发作，而安慰剂组未见这一现象。出现癫痫样发作的患者永久停止治疗，癫痫样发作均消除。有癫痫病史、服用可降低癫痫阈值的药物、或有其他癫痫危险因素的患者均被排除在之外。鉴于使用Xtandi伴随癫痫风险，应告知患者可能因突然丧失意识而导致严重伤害的风险。

Xtandi的推荐剂量为160 mg(4个40 mg胶囊)，每日口服1次。该药可与食物同服，而且不要求同时使用类固醇。

爱思唯尔版权所有  未经授权请勿转载

ST LOUIS (MD Consult) - On August 1, 2012, the US Food and Drug Administration and Astellas Pharma announced the approval of Xtandi (enzalutamide) for the treatment of metastatic castration-resistant prostate cancer who have previously received docetaxel. Xtandi is an oral, once-daily androgen receptor inhibitor.

The safety and effectiveness of Xtandi were evaluated in a randomized, placebo-controlled, multicenter phase 3 clinical trial that included 1199 patients with metastatic castration-resistant prostate cancer who had received prior treatment with docetaxel. The study was designed to measure overall survival in men receiving Xtandi compared with men receiving a placebo. The median overall survival for patients receiving Xtandi was 18.4 months, compared with 13.6 months for the patients receiving placebo.

The most common adverse reactions experienced by patients in the clinical study were asthenia/fatigue, back pain, diarrhea, arthralgia, hot flashes, peripheral edema, musculoskeletal pain, headache, upper respiratory infection, muscular weakness, dizziness, insomnia, lower respiratory infection, spinal cord compression and cauda equina syndrome, hematuria, paresthesia, anxiety, and hypertension. Grade 3 and higher adverse reactions were reported among 47% of Xtandi-treated patients and 53% of placebo-treated patients.

In the randomized clinical trial, seizure occurred in 0.9% of patients who received Xtandi. No patients on the placebo arm experienced seizure. Patients who experienced a seizure were permanently discontinued from therapy. All seizures resolved. Patients with a history of seizure, taking medications known to decrease the seizure threshold, or with other risk factors for seizure were excluded from the clinical trial. Because of the risk of seizure associated with Xtandi use, patients should be advised of the risk of engaging in any activity where sudden loss of consciousness could cause serious harm to themselves or others.

The recommended dose of Xtandi is 160 mg (4 40-mg capsules) administered orally once daily. Xtandi can be taken with or without food and does not require concomitant steroid use.