2017年8月1日，美国食品和药品监管局今天批准Idhifa(enasidenib)为治疗有复发或难治性有一个特异性遗传突变急性髓性白血病(AML)成年患者。该药被批准使用与一个协同诊断，实时IDH2分析，该分析被用于检测在有AML患者在IDH2基因特异性突变。
FDA的药物评估和研究中心血液学和肿瘤产品办公室代理主任和FDA的卓越的肿瘤中心主任Richard Pazdur，M.D.说：“Idhifa是一种靶向治疗满足未满足的需求对有一个IDH2突变有的复发或难治性AML患者治疗，““Idhifa的使用为伴随一个完全缓解在有些患者和减低红细胞和血小板输注两者的需求。”
AML是一种在骨髓中形成的迅速进展癌症和导致在血流和骨髓中异常白血细胞数一个增加。在美国国立卫生院处的过量癌症研究所估算在2017年约21,380人将被诊断有AML；约10,590有AML患者将死亡。
Idhifa是一种异柠檬酸脱氢酶-2抑制剂其作用通过阻断几个促进细胞生长的酶。如在血或骨髓样品利用IDH2分析检测到IDH2突变，患者可能是对用Idhifa治疗合格。
在一项199患者有复发或难治性AML患者有IDH2突变当被实时IDH2分析检测单臂试验研究Idhifa的疗效。试验测量治疗后患者有无疾病的证据和血计数的完全恢复的百分率(完全缓解或CR)，以及患者有无疾病证据和血计数的部分恢复治疗后(完全缓解有部分血液学恢复或CRh)。用一个最小6个月治疗，19 %患者经历CR 共中位8.2个月，和4%患者经历CRh共中位9.6个月。157例患者由于AML在研究开始需要血或血小板输注，34%用Idhifa治疗后不再需要输注。
Idhifa 的常见副作用包括恶心，呕吐，腹泻，胆红素增加水平和食欲减低。妊娠或哺乳喂养妇女不应服用Idhifa因为它可能致危害于发育中胎儿或新生婴儿。
对Idhifa处方资料包括黑框警告一种不良反应被称为分化综合症可能发生和可能被致死如不治疗。分化综合证的体征和症状可能包括发热，呼吸困难，急性呼吸道窘迫群，放射影像肺浸润，胸膜或心包渗出，迅速体重增量，肿胀或肝，肾或多器官功能不全。在症状的首次怀疑时，医生应用皮质激素治疗患者和严密监视患者直至症状消失。.
Idhifa被授予优先审评指定，据此FDA目的是在监管局检查该药的6个月内采取行动对一个申请，如被批准，将显著改善治疗，诊断或预防一种严重条件的安全性和有效性。Idhifa还接受孤儿药物指定，它提供激励帮助和鼓励对罕见疾病药物的开发。
FDA授权Idhifa的批注给予 Celgene公司。FDA授权实时IDH2分析的批准给予Abbott实验室。.

Idhifa Approved for Relapsed/Refractory AML with IDH2 Mutation
The Food and Drug Administration (FDA) has approved Idhifa (enasidenib; Celgene) for the treatment of adults with relapsed or refractory acute myeloid leukemia (AML) with a specific genetic mutation. Idhifa is approved for use with the Real Time IDH2 Assay companion diagnostic (Abbott), intended to identify specific mutations in the IDH2 gene in these patients.
“AML is a complex, heterogeneous disease, which is particularly difficult to treat in the relapsed or refractory setting,” said Martin Tallman, M.D., Hematologic Oncologist and Chief, Leukemia Service at Memorial Sloan Kettering Cancer Center. “IDH2 mutations inhibit the normal maturation of myeloid cells, so having a treatment that targets this mechanism is promising for patients and encouraging to us as physicians who have it as our goal to provide options for every patient.”
Idhifa, an isocitrate dehydrogenase-2 inhibitor, was evaluated in a single-arm trial (n=199) of patients with relapsed or refractory AML who had IDH2 mutations. The study assessed the percentage of patients with complete remission (no evidence of disease and full recovery of blood counts post-treatment) as well as patients with complete remission with partial hematologic recovery.
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After a minimum 6 months of treatment, complete remission was seen in 19% of patients for a median of 8.2 months. Complete remission with partial hematologic recovery was seen in 4% of patients with a median of 9.6 months. Following treatment with Idhifa, 34% of patients who required blood or platelet transfusions at the start of study no longer required them.
Nausea, vomiting, increased bilirubin, and reduced appetite were reported as common adverse effects of Idhifa. The drug carries a Boxed Warning regarding the risk of differentiation syndrome, which can be fatal if untreated. Symptoms may include fever, dyspnea, acute respiratory distress, radiographic pulmonary infiltrates, pleural or pericardial effusions, rapid weight gain, peripheral edema, or hepatic/renal or multi-organ dysfunction.
Idhifa was previously granted FDA Priority Review and Orphan Drug designations. The product will be available as 50mg and 100mg strength tablets in 30-count bottles.