Search

Fifty-six children with refractory acute lymphocytic leukemia (ALL) were assessed for remission-induction responses to VM-26 (250 mg/m2 per week) in combination with prednisone (40 mg/m2 per day) and vincristine (1.5 mg/m2 per week). Each child had been treated intensively with steroids, vincristine, daunorubicin and L-asparaginase. In fact, all patients had failed to respond to previous reinduction therapy with prednisone-vincristine or had relapsed while receiving vincristine. Our intent in this study was to test whether or not addition of VM-26 to prednisone-vincristine would overcome clinical resistance to these established agents. Complete remissions were induced in 17 patients (0.30) over 4 to 6 weeks. Five of these children, all clinically unresponsive to prednisone-vincristine alone, had complete remissions that lasted longer than 1 year; two remain in remission for 2 1/2 years and both are now off therapy. Myelosuppression, the most serious treatment complication, was documented in 20 of 26 evaluable patients. The median time to recovery of normal marrow function was 15 days. These results demonstrate further the potential of VM-26 in combined-drug treatment of refractory ALL. Whether the effectiveness of this combination represents potentiation of prednisone and vincristine activity by VM-26 or some other, as yet unidentified interaction, remains to be determined.

Thirty-eight children and young adults with advanced acute nonlymphocytic leukemia (ANLL) in relapse were treated with VP-16-213 plus azacitidine (5AZ). Each patient had previously received many chemotherapeutic drugs, including anthracyclines and cytarabine. Initially, 16 patients received a 5-day course of VP-16-213 (100 mg/m(2)) daily x 3 days and 5AZ 9150 mg/m(2)) daily x 2 days, repeated after 9-16 days. Since this treatment produced marrow hypoplasia and complete remission (CR) in only one of 16 patients, a more intensive regimen was devised: the remaining 22 patients received a course of VP-16-213 (200 mg/m(2)) daily x 3 days, followed by 5AZ (300 mg/Fm(2)) daily x 2 days, repeated after 1-2 days until the bone marrow became hypoplastic. After two to four courses, 18 patients had marrow hypoplasia and ten of these achieved CR. The proportion of patients achieving CR with the higher doses was significantly greater than that with the initial doses )P less than or equal to 0.05). The toxicity also increased with the higher doses, with major problems due to prolonged pancytopenia. Supportive therapy was required for severe bleeding and infections. We conclude that the intensive treatment with VP-16-213 plus 5AZ can effectively induce remission in patients with refractory advanced acute nonlymphocytic leukemia.

On the basis of previous findings at this institution, VM-26 and Cytosine Arabinoside (ara-C) were used in combination to treat 33 children with refractory acute lymphocytic leukemia (ALL). Chemotherapy was given by vein twice a week for four weeks at dosage of 300 mg/m2 for ara-C and 50, 75, 110, 165, or 200 mg/m2 for VM-26. Ten marrow remissions (nine complete and one partial) were induced, with hypotension (2/33) and bone marrow hypoplasia (20/33) the most significant side effects observed. Therapeutic responses were obtained with each dosage of VM-26 except 75 mg/m2; myelosuppression developed at all dosages, being most prolonged at 200 mg/m2. Ten of the 23 non-responders did not complete their planned courses of therapy. The significance of this information is that combinations of VM-26 and ara-C were effective in patients who were either in late stages of their leukemia or had never achieved an initial remission. All had been previously treated with prednisone, vincristine, daunomycin and L-asparaginase. In addition, seven of the 10 responders had previously received ara-C in other drug combinations. The use of VM-26 and ara-C in combination may be warranted for newly diagnosed patients who are at high risk for treatment failure with first-line drugs.

Combination chemotherapy with VM-26 and ara-C was given to 14 children with acute lymphocytic leukemia who had not responded to initial treatment with prednisone, vincristine, daunomycin, and asparaginase. Nine of these patients had also received ara-C. At diagnosis, five children were classified as having standard prognostic features and nine as being at high risk for treatment failure. The drug combination was administered by vein twice a week for four weeks at dosages of 165 mg/m2 for VM-26 and 300 mg/m2 for araC. Nine complete remissions, five in patients with high-risk leukemia, were induced with acceptable toxicity; all 9 subsequently were given continuation therapy with oral mercaptopurine and methotrexate. Four of the 9 patients have relapsed at 2--21 months. All treatment was stopped in 2 patients after 30 months of complete remission. Combinations of VM-26 and ara-C represent an alternative remission induction treatment for patients who fail to attain initial remission with agents of established effectiveness. These agents may especially benefit patients with prognostic features indicating a high risk of treatment failure.

The clinical pharmacokinetics of teniposide (VM-26, NSC 122819) has been studied in 21 children (median age, 4.7 years) with acute lymphocytic leukemia. Teniposide was administered at a dosage of 165 mg/sq m as a 30- to 60-min i.v. infusion. Patients were studied either on the first or second dosage of the drug. Plasma samples were assayed for teniposide and metabolites by high-performance liquid chromatography with electro-chemical detection. Both compartmental and noncompartmental pharmacokinetic analyses were performed. Systemic clearance and apparent volume of distribution of steady state averaged 13.82 +/- 6.0 ml/min/sq m (S.D.) and 7.9 +/- 4.0 liter/sq m, respectively. Univariate and multivariate stepwise regression analyses were used to construct mathematical models to describe the relationships between certain patient-specific demographic and laboratory values and the pharmacokinetic parameters, systemic clearance, elimination rate constant, and area under the concentration-time curve. A significant relationship between serum alkaline phosphatase and systemic clearance, elimination rate constant, and area under the concentration-time curve was found, suggesting that liver function influences the disposition of this anticancer drug in humans.

We treated 24 children and adolescents with stage III or IV lymphoblastic non-Hodgkin's lymphoma, using a protocol designed for patients with poor-prognosis acute lymphoblastic leukemia (ALL). Early therapy consisted of teniposide plus cytarabine administered before and immediately after prednisone, vincristine, and asparaginase. The two-drug combination was also given intermittently with continuous 6-mercaptopurine and methotrexate during the first year of continuation chemotherapy. Periodic intrathecal methotrexate and delayed cranial irradiation were used to prevent central nervous system involvement. Anthracycline compounds, alkylating agents, high-dose methotrexate, and involved-field irradiation were not used in any phase of treatment. Twenty-two (96%) of the 23 evaluable patients achieved complete remission. With a median follow-up of 2 1/2 years, only four patients have relapsed; the remainder have been disease-free for eight months to more than five years. The projected four-year continuous complete remission rate is 73% for all patients and 79% for the 19 with mediastinal involvement at diagnosis. These results demonstrate that use of teniposide plus cytarabine with an otherwise conventional plan of ALL therapy is an effective approach to the treatment of childhood lymphoblastic lymphoma.