gemtuzumab ozogamicin gemtuzumab ozogamicin gemtuzumab ozogamicin, sold under the brand name mylotarg, is an antibody-drug conjugate (a drug-linked monoclonal antibody) that is used to treat acute myeloid leukemia. gemtuzumab ozogamicinmonoclonal antibodytypewhole antibodysourcehumanized (from mouse)targetcd33clinical datatrade namesmylotargahfs/drugs.commonographmedlineplusa618005license data us dailymed: gemtuzumab_ozogamicin pregnancycategory au: d routes ofadministrationintravenousatc codel01fx02 (who) legal statuslegal status au: s4 (prescription only) ca: rx-only / schedule d uk: pom (prescription only) us: ℞-only eu: rx-only identifierscas number220578-59-6 ydrugbankdb00056 ychemspidernoneunii8gzg754x6mkeggd03259 ychemblchembl1201506 nchemical and physical datamolar mass151500 g·mol−1 ny (what is this?) (verify) the most common side effects include infection, febrile neutropenia, decreased appetite, hyperglycemia, mucositis, hypoxia, hemorrhage, increased transaminase, diarrhea, nausea, and hypotension. medical uses in the united states, gemtuzumab ozogamicin is indicated for newly diagnosed cd33-positive acute myeloid leukemia (aml) for adults and children one month and older and for the treatment of relapsed or refractory cd33-positive aml in adults and children two years and older. mechanism gemtuzumab is a monoclonal antibody to cd33 linked to a cytotoxic agent from the class of calicheamicins (ozogamicin). cd33 is expressed in most leukemic blast cells but also in normal hematopoietic cells, the intensity diminishing with maturation of stem cells. history gemtuzumab ozogamicin was created in a collaboration between celltech and wyeth that began in 1991. the same collaboration later produced inotuzumab ozogamicin. celltech was acquired by ucb in 2004 and wyeth was acquired by pfizer in 2009. in the united states, it was approved under an accelerated-approval process by the fda in 2000, for use in patients over the age of 60 with relapsed acute myelogenous leukemia (aml); or those who are not considered candidates for standard chemotherapy. the accelerated approval was based on the surrogate endpoint of response rate. it was the first antibody-drug conjugate to be approved. within the first year after approval, the fda required a black box warning be added to gemtuzumab packaging. the drug was noted to increase the risk of veno-occlusive disease in the absence of bone marrow transplantation. later the onset of vod was shown to occur at increased frequency in gemtuzumab patients even following bone marrow transplantation. the drug was discussed in a 2008 jama article, which criticized the inadequacy of postmarketing surveillance of biologic agents. a randomized phase iii comparative controlled trial (swog s0106) was initiated in 2004, by wyeth in accordance with the fda accelerated-approval process. the study was stopped on august 20, 2009, prior to completion due to worrisome outcomes. among the patients evaluated for early toxicity, fatal toxicity rate was significantly higher in the gemtuzumab combination therapy group vs the standard therapy group. mortality was 5.7% with gemtuzumab and 1.4% without the agent (16/283 = 5.7% vs 4/281 = 1.4%; p = .01). in june 2010, pfizer withdrew mylotarg from the market at the request of the us fda. however, some other regulatory authorities did not agree with the fda decision, with japan's pharmaceuticals and medical devices agency stating in 2011 that the "risk-benefit balance of gemtuzumab ozogamicin has not changed from its state at the time of approval". in 2017, pfizer reapplied for us and eu approval, based on a meta-analysis of prior trials and results of the alfa-0701 clinical trial, an open-label phase iii trial in 280 older people with aml. in september 2017, gemtuzumab ozogamicin was approved again for use in the united states and in the european union.