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【编译】伊洛前列素吸入剂亮相美国
总部座落于美国旧金山的生物制药公司CoTherix(CTRX) 日前宣布，该公司的前列环素类似物伊洛前列素(iloprost，Ventavis) 吸入剂已获美国食品与药物管理局（FDA）批准用于肺动脉高压症(pulmonary arterial hypertension，PAH)。此前，该品已由研发公司德国先灵（Schering AG）在澳大利亚和欧洲的几个国家率先上市。
CoTherix于2003年10月从先灵公司获得了伊洛前列素在美国市场开发和经营的独家许可权。次年8月﹐该品从FDA处获得了罕见疾病药物身份﹐CoTherix由此得到了为期7年的独家营销权。
罕见药（Orphan Drugs）即指对发病人数少于20 万人的疾病的药物，例如囊性纤维化、克隆氏病、非何杰金氏淋巴瘤、血友病等。在美国约有6000 种罕见病，有的只影响非常少的人群。为了鼓励中小制药企业开发这些被大制药企业忽视的罕见药物，美国政府于1983 年实行了“罕见药法案（Orphan Drug Act）”，研发者据此可获7 年市场独占权，还可以税收信贷的形式申请63％的临床研究费用。
作为罕见病之一，肺动脉高压症患者在美国仅5万人，其中1万5千人已在治疗。尽管市场不大，由于垂涎于政府对罕见药的资金支持和优惠政策，还是吸引了众多的厂家加入了肺动脉高压病治疗药的研发大军。
据报道，在美国已上市的肺动脉高压症用药不但有英国葛兰素史克 (GlaxoSmithKline) 公司的依前列醇（epoprostenol，Flolan）静脉注射剂，美国United Therapeutics公司的瑞莫杜林(treprostinil sodium，Remodulin)皮下/静脉注射剂，还有瑞士艾克蒂莱恩药厂(Actelion)的口服制剂波生坦(bosentan, Tracleer)片等。潜在的竞争还有来自美国辉瑞公司的5型磷酸二脂酶(PDE-5)抑制剂西地那非(Sildenafil)，该品最近已在美国与欧洲以Revatio为商品名申请治疗肺动脉高压适应症。
显然，肺动脉高压症用药市场通道在美国已十分拥挤，CoTherix干嘛还要趟这趟混水，而伊洛前列素又是凭什么魅力令FDA批准的呢？
CoTherix认为，肺动脉高压症可导致患者极度虚弱﹐严重时可致命。当前美国该病症用药品种虽已不乏，但尚无吸入剂型。相比较之，这种无创给药方法更易为病人所接受，并可避免静脉或皮下给药的并发症。CoTherix相信，凭借自己的产品优势与销售力量，伊洛前列素必有广阔前景。
FDA对伊洛前列素的批准则是基于一项对203例患者进行的随机、双盲试验的结果。该试验参加者为按美国纽约心脏协会（NYHA）分级达 Ⅲ～Ⅳ级症状的PAH成年患者或与PAH有关的慢性血栓症患者。试验以临床主要终点指标的改善率为依据，具体指标为NYHA功能等级的改善；6分钟步行距离至少提高10%；无病情恶化或死亡。
试验结果，采用伊洛前列素治疗组的PAH患者疗效主要终点的应答率是19%，而安慰剂组仅4%(p=0.0033)。主要终点的3项指标均显示伊洛前列素组更佳。结果还显示，本品耐受性良好。最常见的不良反应为面部潮红、咳嗽、低血压、头痛和恶心。
伊洛前列素是CoTherix推向市场的首类药物﹐也是公司目前唯一的产品。为分得美国肺动脉高压症用药市场一调羹，CoTherix正卯足劲头，打算与众多竞争对手大搏一场。
S00868238 - Scrip Top
Date published: 30 December 2004
Ventavis approved in the US for PAH (pulmonary arterial hypertension)
The US FDA has approved CoTherix's prostacyclin analogue, Ventavis (iloprost) Inhalation Solution, for the treatment of pulmonary arterial hypertension.
The product is already marketed in Europe and Australia for this indication by the originator, Schering AG.
Ventavis, which will be promoted in the US by CoTherix's own sales force, will enter an increasingly crowded market for this rare condition. As an inhaled product, it should fare well against the iv/sc products, GlaxoSmithKline's Flolan (epoprostenol) and United Therapeutics' Remodulin (treprostinil sodium), but also needs to compete with Actelion's oral product, Tracleer (bosentan).
Future competition could also come from Pfizer's PDE-5 inhibitor, sildenafil, which has recently been filed in the US and Europe as Revatio for this indication.
However, the market should support a number of treatment options as only around 15,000 of the estimated 50,000 PAH patients in the US are currently being treated.
The approval of Ventavis is based on a randomised, double-blind trial of 203 adults with NYHA Class III or IV PAH or pulmonary hypertension related to chronic thromboembolic disease in which treatment with Ventavis improved the response rate for the primary efficacy endpoint (a composite of improvement in functional NYHA class, increase in the distance walked in six minutes of at least 10%, and no clinical deterioration or death). PAH patients receiving Ventavis had a response rate of 19% compared with 4% for placebo (p=0.0033). All three components of the endpoint favoured the treatment arm.
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作者:admin@医学,生命科学 2011-04-19 17:14
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