We analyzed the safety and efficacy of Mylotarg (gemtuzumab ozogamicin, an antibody-targeted chemotherapy consisting of a humanized anti-CD33 antibody linked to calicheamicin, a potent antitumor ...antibiotic) in the treatment of 101 patients > or =60 years of age with acute myeloid leukemia (AML) in untreated first relapse in three open-label trials. Mylotarg is administered as a 2-h intravenous infusion at 9 mg/m(2) for two doses with 14 days between doses. The overall remission rate was 28%, with complete remission (CR) in 13% of patients and complete remission with incomplete platelet recovery (CRp) in 15%. Median survival was 5.4 months for all patients and 14.5 months and 11.8 months for patients achieving CR and CRp, respectively. CD33 antigen is present on normal hematopoietic progenitor cells; thus, an expected high incidence of grade 3 or 4 neutropenia (99%) and thrombocytopenia (99%) was observed. The incidences of grade 3 or 4 elevations of bilirubin and hepatic transaminases were 24% and 15%, respectively. There was a low incidence of grade 3 or 4 mucositis (4%) and infections (27%) and no treatment-related cardiotoxicity, cerebellar toxicity, or alopecia. Mylotarg is an effective treatment for older patients with CD33-positive AML in first relapse and has acceptable toxicity.
Three open-label, multicenter trials were conducted to evaluate the efficacy and safety of single-agent Mylotarg (gemtuzumab ozogamicin; CMA-676; Wyeth Laboratories, Philadelphia, PA), an ...antibody-targeted chemotherapy agent, in patients with CD33-positive acute myeloid leukemia (AML) in untreated first relapse.
The study population comprised 142 patients with AML in first relapse with no history of an antecedent hematologic disorder and a median age of 61 years. All patients received Mylotarg as a 2-hour intravenous infusion, at a dose of 9 mg/m(2), at 2-week intervals for two doses. Patients were evaluated for remission, survival, and treatment-emergent adverse events.
Thirty percent of patients treated with Mylotarg obtained remission as characterized by 5% or less blasts in the marrow, recovery of neutrophils to at least 1,500/microL, and RBC and platelet transfusion independence. Although patients treated with Mylotarg had relatively high incidences of myelosuppression, grade 3 or 4 hyperbilirubinemia (23%), and elevated hepatic transaminase levels (17%), the incidences of grade 3 or 4 mucositis (4%) and infections (28%) were relatively low. There was a low incidence of severe nausea and vomiting (11%) and no treatment-related cardiotoxicity, cerebellar toxicity, or alopecia. Many patients received Mylotarg on an outpatient basis (38% and 41% of patients for the first and second doses, respectively). Among the 142 patients, the median total duration of hospitalization was 24 days; 16% of patients required 7 days of hospitalization or less.
Administration of the antibody-targeted chemotherapy agent Mylotarg to patients with CD33-positive AML in first relapse induces complete remissions with what appears to be a favorable safety profile.
The compound CMB-401 is an immunoconjugate consisting of the monoclonal antibody (MAb) hCTM01 directed against polymorphic epithelial mucin covalently bound to the cytotoxic antibiotic calicheamicin ...by an amide linker. We evaluated CMB-401 as monotherapy for the treatment of recurrent platinum-sensitive epithelial ovarian carcinoma (EOC). Twenty-one 21 women aged 38 to 80 years with recurrent EOC (recurrence >6 months after initial platinum-containing chemotherapy) were enrolled. Tumor response and serum cancer antigen 125 (CA125) levels were assessed before and after active treatment. After an initial intravenous (i.v.) dose of hCTM01 (without calicheamicin), the calicheamicin-linked CMB-401 (16 mg/m(2 ) i.v.) was administered over 60 min for up to 7 cycles, with 4 weeks between cycles. Nineteen patients were evaluable. Measurable changes observed following administration of CMB-401 did not meet the criteria for partial remission (PR). CMB-401 was not effective as monotherapy for this type of EOC. Adverse events experienced by patients in the study included nausea (95%), asthenia (90%), abdominal pain (62%), headache (57%), anorexia (57%), and diarrhea (57%), mostly at a toxicity grade level of 1 or 2. Based on published efficacy of conjugates that deliver calicheamicin via hybrid (bifunctional) linkers e.g. gemtuzumab ozogamicin (Mylotarg) in acute myeloid leukemia, we hypothesize that the amide linker used in CMB-401 may have contributed to its failure to induce PR in patients in this study. Use of hybrid linkers to target hCTM01 or other antibodies to EOC may warrant further investigation.
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