痛药领域迎转机？FDA批准礼来NGF止痛药物项目重启 ！

止痛药物曾经因为其广泛的使用领域和巨大的市场前景而获得众多生物医药巨头的追捧。然而随着药物滥用及各种副作用的发现，FDA对这种药物的研发工作由大力支持变为了谨慎对待。对这一转变，辉瑞公司和礼来公司可谓心有戚戚。

不过，最近FDA在审阅了两家公司提交的关于其神经生长因子（NGF）类止痛药物tanezumab先期实验的研究数据，终于打消了对这种药物安全性的疑虑，批准其继续进行中断数年之久的临床三期研究。视线回到2010年时，这种NGF抑制剂类药物曾经有望成为一种突破性药物，分析人士曾预计这种药物上市后的年销售额峰值将达到110亿美元之多。然而，FDA由于担心这种药物在神经系统方面的风险，最终于2012年将其束之高阁。

作为一种新型NGF抑制剂药物，tanezumab是通过作用于一种NGF的蛋白来阻断神经系统对于痛觉的产生起到止痛作用的。研究人员认为这种药物有望用于慢性疼痛的治疗，而目前包括癌症在内的许多疾病都伴随着慢性疼痛的症状，因此tanezumab可谓是前途无量。

在过去的数年，为了拯救tanezumab，礼来和辉瑞公司进行了一系列的先期研究，试图证明这种药物的安全性。如今，随着FDA打消疑虑，两家公司将可以重新开始招募临床三期研究所需的受试者。根据协议，由于FDA批准tanezumab继续进行临床三期研究，礼来公司将向辉瑞公司支付2亿美元的费用。协议中还有高达3亿5千万美元的里程碑奖金和12亿美元的与销售挂钩的协议奖金。礼来公司对这一药物的信心可谓跃然纸上。

此次FDA解冻tanezumab的举措无疑是向市场释放了一个积极的信号。强生、阿斯利康以及Regeneron等被雪藏的NGF止痛药项目都有望在未来重新回到人们的视线中。

详细英文报道：

A once-halted pain candidate from partners Pfizer ($PFE) and Eli Lilly ($LLY) now has the green light to resume late-stage testing, as the FDA has lifted a clinical hold tied to some serious safety concerns for the whole class of drugs.

The treatment, tanezumab, works by targeting nerve growth factor, a protein that regulates how the body processes pain. Back in 2010, NGF inhibitors seemed poised to become blockbusters and upend the market for chronic pain treatments, with analysts forecasting group sales north of $11 billion a year. But emerging ties between NGF blockade and dangerous changes to the nervous system and joint destruction spurred widespread concerns and eventually led the FDA to clamp down, putting a hold on tanezumab in 2012.

Despite the then-indefinite delay on Pfizer's antibody, Lilly stepped in in 2013 with a $1.8 billion deal to partner up on the drug, believing the regulatory climate would soon change and NGF inhibitors would fall back into vogue.

Now, after presenting the agency with some preclinical data demonstrating tanezumab's safety, the pair is back in business, Pfizer said, resuming Phase III development where it left off in 2012. Tanezumab is in development as a treatment for chronic pain tied to osteoarthritis, lower back issues and cancer.

Under Lilly's license deal, Pfizer gets $200 million based on the FDA's action, and Lilly has promised $350 million in regulatory milestones and about $1.2 billion more tied to sales.

"We're pleased to work with Pfizer to resume the Phase III program, and we're confident that tanezumab, if approved, can be an innovative treatment with the potential to help millions suffering from painful conditions," Lilly Bio-Medicines President David Ricks said in a statement.

The FDA's change of heart could have a read-through for some other paused NGF programs, including efforts from Johnson & Johnson ($JNJ), AstraZeneca ($AZN) and Regeneron ($REGN).