homoharringtonine and Thrombocytopenia

Omacetaxine mepesuccinate is a first-in-class cephalotaxine demonstrating clinical activity in chronic myeloid leukemia. A subcutaneous (SC) formulation demonstrated efficacy and safety in phase 1/2 trials in patients previously treated with ≥1 tyrosine kinase inhibitor. This study assessed pharmacokinetics and safety of SC omacetaxine in patients with advanced cancers.. Omacetaxine 1.25 mg/m(2) SC was administered BID, days 1-14 every 28 days for 2 cycles, until disease progression or unacceptable toxicity. Blood and urine were collected to measure omacetaxine concentrations and inactive metabolites. Adverse events, including QT interval prolongation, were recorded. Tumor response was assessed at cycle 2 completion.. Pharmacokinetic parameters were estimated from cycle 1, day 1 data in 21 patients with solid tumors or hematologic malignancies and cycle 1, day 11 data in 10 patients. Omacetaxine was rapidly absorbed, with mean peak plasma concentrations observed within 1 h, and widely distributed, as evidenced by an apparent volume of distribution of 126.8 L/m(2). Plasma concentration versus time data demonstrated biexponential decay; mean steady-state terminal half-life was 7 h. Concentrations of inactive metabolites 4'-DMHHT and cephalotaxine were approximately 10 % of omacetaxine and undetectable in most patients, respectively. Urinary excretion of unchanged omacetaxine accounted for <15 % of the dose. Grade 3/4 drug-related adverse events included thrombocytopenia (48 %) and neutropenia (33 %). Two grade 2 increases in QTc interval (>470 ms) were observed and were not correlated with omacetaxine plasma concentration. No objective responses were observed.. Omacetaxine is well absorbed after SC administration. Therapeutic plasma concentrations were achieved with 1.25 mg/m(2) BID, supporting clinical development of this dose and schedule.

Topics: Adult; Aged; Antineoplastic Agents, Phytogenic; Female; Half-Life; Harringtonines; Hematologic Neoplasms; Homoharringtonine; Humans; Injections, Subcutaneous; Long QT Syndrome; Male; Middle Aged; Neoplasms; Neutropenia; Thrombocytopenia; Tissue Distribution

Homoharringtonine (HHT) is a plant alkaloid that is derived from a Chinese evergreen tree. Its mechanism of action is thought to be by inhibition of protein, DNA, and RNA synthesis by inhibition of chain initiation. The treatment of acute myelogenous leukemia (AML) in children, has been hampered by few new effective agents developed in the past 30 years. Significant numbers of children still die of this disease. The purpose of this study is to evaluate the efficacy and toxicity of HHT for the therapy of refractory AML in children.. Patients entered the study and were treated with HHT 7mg/m(2)/day for 10 days. The cycles could be repeated every 21 days depending on recovery from myelosuppression.. Thirty-seven patients entered the study, with twenty-eight evaluable for response. Complete response was obtained in four and a partial response in one (response rate 5/28 = 18%). Significant toxicities included prolonged severe myelosuppression in all responsive patients and neuropathogenic pain in two patients. The median duration of response was 62 days with a range of 28-126 days.. HHT has activity against chemotherapy resistant AML in children, with tolerable toxicity. This agent warrants further clinical evaluation in combination with other agents or perhaps biologic response modifiers which will hopefully lead to useful therapeutic options. Med Pediatr Oncol 2001;37:103-107.

Topics: Adolescent; Antineoplastic Agents, Phytogenic; Child; Child, Preschool; Disease Progression; Drug Resistance, Neoplasm; Female; Harringtonines; Homoharringtonine; Humans; Infant; Infusions, Intravenous; Leukemia, Myeloid, Acute; Male; Neutropenia; Thrombocytopenia; Treatment Outcome

To explore the clinical efficacy and adverse effects of GHA(G-CSF+homoharringtonin+cytarabine C) and new combined priming chemotherapeutic regimens(GHAA/GHTA) with high efficacy and low toxicity for treatment of relapsed and refractory acute myeloid leukemia(AML) and myelodysplastic syndrome(MDS), and to analyze the relation of above-mentioned regimens with the expression of co-stimuolating molecule B7.1.. Standard GHA regimen consisting of G-CSF: 100 µg/(m2·d) subcutaneous injection, d 0-14; homoharringtonine: 1.0 mg/(m2·d) intravenous drip, d 1-14; Ara-C: 7.5-10 mg/(m2·d) subcutaneous injection, q12h, d 1-14. Other regimens as GHAA/GHTA were combined respectively with aclarubicin 20 mg d 1-7, or pirarubicin 20 mg d 1-7. 74 patients with refractory AML and 46 patients with MDS received these priming chemotherapy. The clinical efficacy and toxicity of above-mentioned priming chemotherapy were compared with 56 patients received routine chemotherapy (MA/TAE) respectively. And the expression of costimulatory molecule B7.1 on leukemia cells in patients of different subtypes was also detected by immunofluoressence and its relationship with clinical efficiency was explored.. (1) for AML patients treated with priming chemotherapy, the total remission was 67.56% (CR 54.05%, PR 13.51%), which was much higher than that of patients received routine chemotherapy (P<0.05). The CR rate of AML-M2 and AML-M5 group (65.51%, 61.90% respectively) was much higher than that of AML other subtypes (P<0.05), and the longest remission period lasted for 4 years; (2) for MDS patients treated with priming chemotherapy, the total remission was 60.87% (CR 45.65%, PR 15.22%), which was also significantly higher than that of patients received routine chemotherapy (P<0.05); (3) in comparison with patients received standard GHA priming regimen, the remission rate of combined priming chemotherapy GHAA/GHTA was significantly higher both in patients with AML (85.18%) and MDS (81.25%); (4) side effects after chemotheropy, including granulocyte deficiency, thrombocytopenia and anemia etc, lasted for 7-14 days; the severe infection rate was 1%, there were no severe bleeding, digest effect and damage of function in heart, liver and kidney. The therapy-related mortality was zero. Compared with routine chemotherapy, priming chemotherapy proved significantly safe and effective (P<0.05); (5) the expression rate of costimulatory molecule B7.1 showed large variance between AML and MDS, it was higher in AML-M2/AML-M5 and lower in AML of other subtypes (P<0.05). In the same case, B7.1 expression was positive correlated with efficiency of priming chemotherapy.. GHA priming chemotherapy, as well as other combination regimens GHAA/GHTA, are well-tolerated, effective regimens for refractory AML and advanced MDS, without severe side effects and therapy-related mortality. Especially the new regimens GHAA/GHTA has better efficacy, which are proved more efficient than conventional GHA. Efficiency of priming chemotherapy is positive correlated with B7.1 expression, its mechanism will be further explored.

Topics: Aclarubicin; Antineoplastic Combined Chemotherapy Protocols; B7-1 Antigen; Cohort Studies; Cytarabine; Doxorubicin; Granulocyte Colony-Stimulating Factor; Granulocytes; Harringtonines; Homoharringtonine; Humans; Leukemia, Myeloid, Acute; Myelodysplastic Syndromes; Recurrence; Thrombocytopenia

Homoharringtonine (HHT) is a novel plant alkaloid that produced a complete hematologic remission (CHR) in 72% of patients with late chronic phase chronic myelogenous leukemia (CML). Cytogenetic (CG) remissions were noted in 31%. In this study, six courses of HHT were administered to 90 patients with early chronic phase CML (< 1 year from diagnosis). Patients then received interferon-alpha (IFN-alpha) with a target dose of 5 MU/m2 daily. Results were compared with those in a prior group of patients treated with IFN-alpha-based therapy between 1982 and 1990. Ninety-two percent of patients achieved CHR with HHT; CG responses were observed in 60% and were major in 27%. Both CHR and CG response rates were significantly higher than those seen in historical control patients after 6 months of IFN-alpha therapy. After receiving HHT, patients required lower doses of IFN-alpha to maintain a CHR. The median dose delivered was 2.4 MU/m2. This reduction in IFN-alpha dose was associated with a lower incidence of myalgia and gastrointestinal (GI) disturbances than that seen in patients treated at the 5 MU/m2 dose. Overall, CG responses were seen in 66% of the patients who received HHT and IFN-alpha compared with 61% of the historical control patients. HHT is a very effective treatment of early chronic phase CML, and ongoing trials are investigating the simultaneous administration of HHT and IFN-alpha, as well as that of HHT and low-dose cytosine arabinoside in patients failing IFN-alpha therapy.

Topics: Adult; Aged; Antineoplastic Agents, Phytogenic; Antineoplastic Combined Chemotherapy Protocols; Granulocytes; Harringtonines; Hematopoietic Stem Cell Transplantation; Homoharringtonine; Humans; Interferon-alpha; Karyotyping; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Leukocyte Count; Middle Aged; Platelet Count; Remission Induction; Thrombocytopenia

Homoharringtonine (HHT) is a plant alkaloid with potent myelosuppressive activity and little toxicity when used in a continuous infusion schedule. The antileukemic efficacy of HHT has been shown in acute myeloid leukemia, but has not been investigated in chronic myelogenous leukemia (CML). Seventy-one patients with Philadelphia chromosome-positive (Ph+) CML in late chronic phase (time from diagnosis to therapy longer than 12 months) were treated with a continuous infusion of HHT at a daily dose of 2.5 mg/m2 for 14 days for remission induction and for 7 days every month for maintenance. The median number of courses given was 6 (range, 1 to 35) and 21 patients (30%) continue on treatment. Forty-two of 58 patients (72%) evaluable for hematologic response achieved a complete hematologic remission, and 9 (16%) had a partial hematologic remission. Twenty-two of 71 patients (31%) developed a cytogenetic response; it was major (Ph+ cells less than 35%) in 11 (15%) and complete (Ph+ cells 0%) in 5 (7%). Significant myelosuppression occurred in 39% of induction courses and 9% of maintenance courses. Fever or documented infection was present in 26% of induction courses and in only 8% of maintenance courses. Nonmyelosuppressive toxicity was minimal. Homoharringtonine produced hematologic remissions in the majority of patients with advanced chronic-phase CML. Cytogenetic response occurred in some patients without an association with myelosuppression, and these responses may be prolonged. Future studies investigating homoharringtonine in combination with other active agents in CML, such as interferon, are warranted.

Topics: Adult; Aged; Antineoplastic Agents, Phytogenic; Combined Modality Therapy; Diarrhea; Female; Harringtonines; Homoharringtonine; Humans; Immunologic Factors; Infections; Interferon-alpha; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Leukemia, Myeloid, Chronic-Phase; Leukopenia; Male; Middle Aged; Remission Induction; Survival Rate; Thrombocytopenia; Treatment Outcome