首款IDH2口服抑制剂enasidenib（商品名IDHIFA，曾用名AG-221）获美国FDA批准上市，用于治疗罹患复发性或难治性急性骨髓性白血病（AML），且带有IDH2突变的成人患者。enasidenib是首款针对IDH2的口服抑制剂，也是美国FDA批准的唯一一款针对这一患者群体的疗法。
批准日期：2017年8月1日；公司：Celgene Corporation
Idhifa(恩西地替尼[enasidenib])片 供口服使用
作用机制
Enasidenib是一种异柠檬酸脱氢酶2(IDH2)酶的小分子抑制剂。Enasidenib靶向突变体IDH2 变异体R140Q，R172S，和R172K在体外比野生型酶在浓度较低约40-倍。突变体IDH2酶被enasidenib的抑制作用导致减低2-羟戊二酸[2-hydroxyglutarate(2-HG)]水平和诱导骨髓分化在体外和在体内在IDH2突变AML的小鼠移植物模型，在来自患者有突变的IDH2AML血样品中，enasidenib减低2-HG水平，减低母细胞计数[blast counts]和增加成熟骨髓细胞百分率。
适应证和用途
IDHIFA是一种异柠檬酸脱氢酶-2抑制剂适用为成年患者有复发或难治性急性髓性白血病(AML)的治疗当被FDA-批准的测试检测到有一个异柠檬酸脱氢酶-2(IDH2)突变。
剂量和给药方法
100 mg口服每天1次直至疾病进展或不可接受毒性。
剂型和规格
片：50mg或100mg
禁忌证
无
警告和注意事项
胚胎-胎儿毒性：IDHIFA可能致胎儿危害当给予一位妊娠妇女。忠告对胎儿潜在风险。
不良反应
最常见不良反应(≥20%)包括恶心，呕吐，腹泻，升高的胆红素，和食欲减低.
在特殊人群中使用
哺乳：建议妇女不要哺乳喂养。
包装规格/贮存和处置
供应
50-mg片：淡黄色至黄色椭圆形薄膜包衣片一侧凹陷”ENA“和在其他侧“50”。
●30-片50-mg片与一个干燥剂罐瓶(NDC 59572-705-30)
●30-片100-mg片与干燥剂罐瓶(NDC 59572-710-30)
100-mg片：淡黄色至黄色胶囊形膜包衣一侧凹陷”ENA“和在其他侧“100”。
 贮存
贮存在20°C-25°C(68°F-77°F)；外出允许在15°C-30°C间(59°F-86°F)[见USP控制室温]。瓶紧密闭保存。贮存在原始瓶(与一个干燥剂罐)避潮湿保护。
https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/209606s000lbl.pdf
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 eva luated 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
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.