2018年9月13日，美国FDA批准Lumoxiti（moxetumomab pasudotox-tdfk）静脉注射剂用于治疗复发性或难治性毛细胞白血病（hairy cell leukemia, HCL）成人患者。这些患者已经至少接受过两种全身性治疗，其中包括嘌呤核苷类似物（purine nucleoside analog）疗法。Lumoxiti是一种靶向CD22的细胞毒素，这是治疗HCL患者的第一例细胞毒素疗法。 HCL是一种罕见的，生长缓慢的血癌，它是由于骨髓生成过多的B淋巴细胞而造成的。随着白血病细胞的增多，健康白细胞、血红细胞和血小板生成的数量下降。HCL可能导致严重甚至致命的健康状况，包括感染、出血和贫血。虽然很多患者最初会对疗法产生反应，但是高达40%的患者会复发，复发患者的治疗选择非常有限。   Lumoxiti是一种靶向CD22的重组免疫毒素（immunotoxin）。免疫毒素综合了抗体能够靶向运送药物的特异性和毒素杀死肿瘤细胞的效力。Lumoxiti将CD22抗体与抗原结合的部分与一种毒素融合在一起。CD22是只在B淋巴细胞中表达的跨膜蛋白，它在HCL细胞表面的受体密度更高，因此是治疗这一癌症的重要靶点。在与CD22结合后，这一分子会进入细胞，被处理并且释放出毒素蛋白，它会抑制蛋白转译，从而导致细胞凋亡。Lumoxiti已经获得FDA授予的孤儿药资格，快速通道资格和优先审评资格。   FDA的批准是基于一项单臂，开放标签的多中心临床3期试验。总计80名HCL患者接受了Lumoxiti的治疗，他们至少接受过2种全身性疗法的治疗，其中包括嘌呤核苷类似物疗法。这一试验的主要终点为持久的完全缓解（CR），定义为在达到完全缓解后继续维持缓解超过180天。30%参加试验的患者达到持久的CR，总缓解率（包括部分缓解和完全缓解）为75%。 “Lumoxiti填补了HCL患者未满足的医疗需求，他们在使用其它FDA批准的疗法后疾病继续恶化，” FDA肿瘤卓越中心主任Richard Pazdur博士说：“美国国家癌症研究所进行的重要研究，带来了这一罕见血癌新疗法的研发和临床试验。”   阿斯利康公司的执行副总裁兼全球肿瘤学部负责人Dave Fredrickson先生说：“今天FDA批准Lumoxiti对HCL患者来说是一个重要的里程碑。对于这些患者来说，这一批准是20多年来第一款FDA批准的针对他们疾病的疗法。 FDA Approval of LUMOXITI (moxetumomab pasudotox-tdfk) for Certain Patients with Relapsed or Refractory Hairy Cell Leukemia Hairy cell leukemia (HCL) is a rare, chronic, and slow-growing leukemia in which the bone marrow overproduces abnormal B cell lymphocytes. HCL can result in serious conditions, including infections, bleeding and anemia. Approximately 1,000 people are diagnosed with HCL in the US each year. HCL accounts for up to 3% of all adult leukemias. While many patients initially respond to treatment, 30% to 40% will relapse five to ten years after their first treatment. With no established standard of care and very few treatments available, there remains significant unmet medical need for people with relapsed or refractory HCL. IMPORTANT SAFETY INFORMATION, INCLUDING BOXED WARNING WARNING: CAPILLARY LEAK SYNDROME and HEMOLYTIC UREMIC SYNDROME Capillary Leak Syndrome (CLS), including life-threatening cases, occurred in patients receiving LUMOXITI. Monitor weight and blood pressure; check labs, including albumin, if CLS is suspected. Delay dosing or discontinue LUMOXITI as recommended [see Dosage and Administration and Warnings and Precautions]. Hemolytic Uremic Syndrome (HUS), including life-threatening cases, occurred in patients receiving LUMOXITI. Monitor hemoglobin, platelet count, serum creatinine, and ensure adequate hydration. Discontinue LUMOXITI in patients with HUS [see Dosage and Administration and Warnings and Precautions ]. WARNINGS AND PRECAUTIONS Capillary leak syndrome (CLS), including life-threatening cases, has been reported among patients treated with LUMOXITI and is characterized by hypoalbuminemia, hypotension, symptoms of fluid overload, and hemoconcentration. In the combined safety database of HCL patients treated with LUMOXITI, CLS occurred in 34% (44/129) of patients, including Grade 2 in 23% (30/129), Grade 3 in 1.6% (2/129), and Grade 4 in 2% (3/129). Most cases of CLS occurred in the first 8 days (range:1 to 19) of a treatment cycle, however, cases have also been reported on other days throughout the cycle. The median time to resolution of CLS was 12 days (range:1 to 53). Monitor patient weight and blood pressure prior to each LUMOXITI infusion and as clinically indicated during treatment. Assess patients for signs and symptoms of CLS, including weight gain (increase in 5.5 pounds (2.5 kg) or ≥ 5% from Day 1 of current cycle), hypotension, peripheral edema, shortness of breath or cough, and pulmonary edema and/or serosal effusions. In addition, the following changes in laboratory parameters may help identify CLS: hypoalbuminemia, elevated hematocrit, leukocytosis, and thrombocytosis. CLS may be life-threatening or fatal if treatment is delayed. Counsel patients to seek immediate medical attention should signs or symptoms of CLS occur at any time. Patients who develop CLS should receive appropriate supportive measures, including concomitant oral or intravenous corticosteroids, and hospitalization as clinically indicated. Withhold LUMOXITI for Grade 2 CLS until resolution, and permanently discontinue for Grade ≥ 3 CLS. Hemolytic Uremic Syndrome (HUS), including life threatening cases, has been reported in patients treated with LUMOXITI and is characterized by the triad of microangiopathic hemolytic anemia, thrombocytopenia, and progressive renal failure. In the combined safety database of HCL patients treated with LUMOXITI, HUS occurred in 7% (9/129) of patients, including Grade 3 in 3% (4/129) and Grade 4 in 0.8% (1/129). Most cases of HUS occurred in the first 9 days (range:1 to 16) of a treatment cycle, however, cases have also been reported on other days throughout the cycle. The median time to resolution of HUS was 11.5 days (range:2 to 44). All cases resolved, including those who discontinued LUMOXITI. Avoid LUMOXITI in patients with prior history of severe thrombotic microangiopathy (TMA) or HUS. Administer prophylactic intravenous fluids before and after LUMOXITI infusions. In Study 1053, patients with a platelet count≥ 100,000/mm received low-dose aspirin on Days 1 through 8 of each 28-day cycle for prophylaxis of thrombosis. Monitor blood chemistry and complete blood counts prior to each dose and on Day 8 of each treatment cycle. Monitoring mid-cycle is also recommended. Consider the diagnosis of HUS in patients who develop hemolytic anemia, worsening or sudden onset of thrombocytopenia, increase in creatinine levels, elevation of bilirubin and/or LDH, and have evidence of hemolysis based on peripheral blood smear schistocytes. The events of HUS may be life-threatening if treatment is delayed with increased risk of progressive renal failure requiring dialysis. If HUS is suspected initiate appropriate supportive measures, including fluid repletion, hemodynamic monitoring, and consider hospitalization as clinically indicated. Discontinue LUMOXITI in patients with HUS. Renal Toxicity has been reported in patients treated with LUMOXITI therapy. In the combined safety database of HCL patients treated with LUMOXITI, 26% (34/129) reported adverse events of renal toxicity, including acute kidney injury (2.3%), renal failure (2.3%), renal impairment (1.6%), serum creatinine increased (17%), and proteinuria (8%). Grade 3 acute kidney injury occurred in 1.6% (2/129) of patients. Based on laboratory findings, during treatment, serum creatinine increased by two or more grades from baseline in 22% (29/129) of patients, including increases of Grade 3 in 1.6% (2/129) of patients. At the end of treatment, serum creatinine levels remained elevated at 1.5- to 3-times the upper limit of normal in 5% of patients. Patients who experience HUS, those ≥ 65 years of age, or those with baseline renal impairment may be at increased risk for worsening of renal function following treatment with LUMOXITI. Monitor renal function prior to each infusion of LUMOXITI, and as clinically indicated throughout treatment. Delay LUMOXITI dosing in patients with Grade ≥ 3 elevations in creatinine, or upon worsening from baseline by ≥ 2 grades. Infusion Related Reactions occurred in patients treated with LUMOXITI, and were defined as the occurrence of any one of the following events on the day of study drug infusion: chills, cough, dizziness, dyspnea, feeling hot, flushing, headache, hypertension, hypotension, infusion related reaction, myalgia nausea, pyrexia, sinus tachycardia, tachycardia, vomiting, or wheezing. In Study 1053, infusion related reactions occurred in 50% (40/80) of patients, including Grade 3 events in 11% (9/80) of patients. The most frequently reported infusion related events were nausea (15%), pyrexia (14%), chills (14%), vomiting (11%), headache (9%), and infusion related reaction (9%). Infusion related reactions may occur during any cycle of treatment with LUMOXITI. Premedicate with antihistamines and antipyretics prior to each LUMOXITI dose. If a severe infusion related reaction occurs, interrupt the LUMOXITI infusion and institute appropriate medical management. Administer an oral or intravenous corticosteroid approximately 30 minutes before resuming, or before the next LUMOXITI infusion. Electrolyte Abnormalities: In the combined safety database of HCL patients treated with LUMOXITI, electrolyte abnormalities occurred in 57% (73/129) of patients with the most common electrolyte abnormality being hypocalcemia occurring in 25% of patients. Grade 3 electrolyte abnormalities occurred in 14% (18/129) of patients and Grade 4 electrolyte abnormalities occurred in 0.8% (1/129) of patients. Electrolyte abnormalities co-occurred in the same treatment cycle with CLS, HUS, fluid retention, or renal toxicity in 37% (48/129) of patients. Monitor serum electrolytes prior to each dose and on Day 8 of each treatment cycle. Monitoring mid-cycle is also recommended. ADVERSE REACTIONS Most common non-laboratory adverse reactions (≥ 20%) of any grade were infusion related reactions (50%), edema peripheral (39%), nausea (35%), fatigue (34%), headache (33%), pyrexia (31%), constipation (23%), anemia (21%), and diarrhea (21%). The most common Grade 3 or 4 adverse reactions (reported in at least ≥ 5% of patients) were hypertension, febrile neutropenia, and HUS. Most common laboratory abnormalities (≥ 20%) of any grade were creatinine increased, ALT increased, hypoalbuminemia, AST increased, hypocalcemia, hypophosphatemia, hemoglobin decreased, neutrophil count decreased, hyponatremia, blood bilirubin increased, hypokalemia, GGT increased, hypomagnesemia, platelet count decreased, hyperuricemia, and alkaline phosphate increased. Adverse reactions resulting in permanent discontinuation of LUMOXITI occurred in 15% (12/80) of patients. The most common adverse reaction leading to LUMOXITI discontinuation was HUS (5%). The most common adverse reaction resulting in dose delays, omissions, or interruptions was pyrexia (3.8%). SPECIFIC POPULATIONS Pregnancy: There are no available data on LUMOXITI use in pregnant women to inform a drug-associated risk of major birth defects and miscarriage. Advise pregnant women of the potential risk to a fetus. Lactation: Advise women not to breastfeed. Geriatric Use: Exploratory analyses suggest a higher incidence of adverse reactions leading to drug discontinuation (23% versus 7%) and renal toxicity (40% versus 20%) for patients 65 years of age or older as compared to those younger than 65 years. About LUMOXITI LUMOXITI™ (moxetumomab pasudotox-tdfk, formerly CAT8015 or HA22) is a CD22-directed cytotoxin and a first-in-class treatment in the US for adult patients with relapsed or refractory hairy cell leukemia (HCL) who have received at least two prior systemic therapies, including treatment with a purine nucleoside analog. LUMOXITI is not recommended in patients with severe renal impairment (CrCl ≤ 29 mL/min). It comprises the CD22 binding portion of an antibody fused to a truncated bacterial toxin; the toxin inhibits protein synthesis and ultimately triggers apoptotic cell death. LUMOXITI has been granted Orphan Drug Designation by the FDA for the treatment of HCL. https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/761104s000lbl.pdf