FDA药品审评与研究中心(CDER)主任George Tidmarsh在10月27日的生物技术创新组织(BIO)患者倡导变革者活动中发表讲话,呼吁制药行业提高新药候选药物遴选标准,强调“边际治疗”(Marginal Treatments)可能弊大于利(does more harm than good)。
在会上,Tidmarsh建议患者和患者倡导组织向药企施加压力,提高创新标准。他提醒“一定要认识到,作为患者和患者倡导组织,如果我们放低标准,那将更加糟糕”,因为“如果批准一款不太好或糟糕的药物,不仅创新会被抑制,有时还会使资金流向其他领域。”(It's important to recognize, as patients and patient advocates that it's worse for you if we lower the standards, because if we approve a not-so-good or bad drug, it inhibits innovation, and it sometimes stifles money into that area...)
针对临床试验中的交叉设计,Tidmarsh说:“我们不希望公司在这些确证性试验中采用交叉设计。如果采用交叉设计并允许标准治疗患者在疾病进展时接受试验药物,就会使总生存期的评估变得复杂。”(We don't like companies to do a crossover in these confirmatory trials...We muddy the water on overall survival if you do a crossover and allow the standard-of-care treatment patients to get the experimental drug...at the time of progression.)他还提到,尽管FDA不断提醒公司不要采用交叉设计,但公司仍然会这样做,这导致无法准确评估总生存期,从而需要做出艰难的决策(hard decisions we need to make)。
他以安进(Amgen)的Lumakras(sotorasib)确证性试验为例说明这一观点,还进一步驳斥了药企认为“无交叉试验则存在招募困难”的论点(最近礼来高管还特别强调这一点),“你们(药企)不需要向主要研究者妥协(设计交叉试验),因为这会导致更糟糕的结果。”(You don't have to bend to the investigators...because you end up worse off down the line.)
针对生物标志物的使用,Tidmarsh认为“当评估生物标志物时,药物对生物标志物的影响程度至关重要。药物可能会影响生物标志物,但并非所有变化都具有临床意义。”(the magnitude of benefit is critical. A drug may impact a biomarker, but not all changes are clinically meaningful)
他提到FDA最近授予Stealth BioTherapeutics公司的巴特综合征药物Forzinity(elamipretide)加速审批的决定(该药曾收FDA完全回应函)。他认为该研究事实上未达到统计学意义,但FDA还是批准了该药,其原因是考虑到患者和一线医生的反馈。“因为该药物是注射剂,对孩子来说很痛苦,如果看不到效果,父母不会继续使用。”(because it was injectable, it was painful for the child, a parent wouldn't want to continue to use it if they weren't seeing benefit)
“CDER将评估用于FDA批准的替代终点。尽管使用这些替代终点无疑使患者受益,因为它们使有价值的治疗更快可及,但在确证性试验中也出现了一些显著的失败案例,例如杜氏肌营养不良症(DMD)中的外显子跳跃疗法。对于一些疾病,如狼疮性肾炎,公司尚未开展试验以证明在‘硬’临床终点(如进展至终末期肾病)方面的获益。因此,我们批准了一些具有显著毒性的药物,例如尚未被证明对患者提供直接临床益处的伏环孢素(voclosporin)。我们将仔细审视替代终点的使用,以确定我们可以在哪些方面进一步加速有前景药物的批准,同时要求公司开展必要的试验以确认实际的临床获益。”(CDER will be evaluating surrogate endpoints used for FDA approval. While there is no doubt that the use of such endpoints has benefited patients by bringing valuable treatments to patients sooner, there have been notable failures in confirmatory trials, such as those for exon skipping therapies in DMD. And for some diseases such as lupus nephritis, companies have not run trials to demonstrate a benefit on hard clinical endpoints like progression to end stage renal disease. So we have approved drugs with significant toxicity like voclosporin that has not been shown to provide a direct clinical benefit for patients. We will be taking a close look at the use of surrogate endpoints to see where we can further accelerate promising drugs faster while requiring companies to perform the trials necessary to confirm actual clinical benefit.)