Ann M. Mohrbacher

Pharmacokinetics-Based Integration of Multiple Doses of Intravenous Pegaspargase in a Pediatric Regimen for Adults With Newly Diagnosed Acute Lymphoblastic Leukemia

PURPOSEnAsparaginase treatment is standard in all pediatric acute lymphoblastic leukemia (ALL) regimens, whereas in adults, it is either excluded or administered for a shorter duration. Several adult ALL protocols are adapting pediatric regimens, but the optimal implementation of asparaginase is not well studied, considering its potential higher toxicity. We studied a pegaspargase dosing strategy based on its pharmacokinetic characteristics in adults.nnnPATIENTS AND METHODSnBetween 2004 and 2009, 51 adults age 18 to 57 years with newly diagnosed ALL were treated with a regimen adapted from a pediatric trial that included six doses of intravenous pegaspargase at 2,000 IU/m(2) per dose. Intervals between doses were longer than 4 weeks and rationally synchronized with other chemotherapy drugs to prevent overlapping toxicities. Pegaspargase was administered with steroids to reduce hypersensitivity. Asparaginase-related toxicities were monitored after 173 pegaspargase doses.nnnRESULTSnThe most common grade 3/4 asparaginase-related toxicities were lengthy hyperbilirubinemia and transaminitis, occasionally resulting in subsequent treatment delays. All toxicities resolved spontaneously. Forty-five percent of patients were able to receive all six doses of pegaspargase, and 61% received ≥ three doses. In only 20% of patients, the drug was discontinued after pegaspargase-related serious toxicity. Ninety-six percent achieved complete remission, almost all within 4 weeks, and a low induction death rate was seen. Seven-year disease-free and overall survival were 58% and 51%, respectively.nnnCONCLUSIONnOur dose and schedule of pegaspargase, based on its pharmacokinetics, and our detailed toxicity profile could be applied for safer adaptation of pediatric ALL protocols in adults.

Adding ascorbic acid to arsenic trioxide produces limited benefit in patients with acute myeloid leukemia excluding acute promyelocytic leukemia.

Arsenic trioxide (ATO) is highly effective in acute promyelocytic leukemia (APL), but despite its multiple mechanism of action, it has no activity in acute myeloid leukemia (AML) that excludes APL (non-APL AML). Ascorbic acid (AA) and ATO induces apoptosis in AML cell lines by depleting intracellular glutathione and generation of reactive oxygen species. In this study, we evaluated the effect of ATO plus AA in patients with non-APL AML. The study enrolled patient aged 18 or older with relapsed or refractory AML (non-APL) after conventional chemotherapy or previously untreated patients 55xa0years or older who were unfit for standard induction chemotherapy for AML. Intravenous ATO (0.25xa0mg/kg/day over 1–4xa0h) was given with intravenous AA (1xa0g/day over 30xa0min after ATO) for 5xa0days a week for 5xa0weeks (25 doses). Eleven AML patients were enrolled, including six previously untreated elderly patients aged 66–84xa0years in whom five had antecedent hematological disorder (ADH). Among 10 evaluable patients, one achieved a CR one a CRi and 4 patients had disappearance of blasts from peripheral blood and bone marrow. Five of the six responders were seen in previously untreated elderly patients. ATO related toxicity was mild. The combination of ATO and AA has limited clinical meaningful antileukemia activity in patients with non-APL AML.

Phase I Study of Fenretinide Delivered Intravenously in Patients with Relapsed or Refractory Hematologic Malignancies: a California Cancer Consortium Trial.

Purpose: A phase I study was conducted to determine the MTD, dose-limiting toxicities (DLT), and pharmacokinetics of fenretinide delivered as an intravenous emulsion in relapsed/refractory hematologic malignancies. Experimental Design: Fenretinide (80–1,810 mg/m2/day) was administered by continuous infusion on days 1 to 5, in 21-day cycles, using an accelerated titration design. Results: Twenty-nine patients, treated with a median of three prior regimens (range, 1–7), were enrolled and received the test drug. Ninety-seven courses were completed. An MTD was reached at 1,280 mg/m2/day for 5 days. Course 1 DLTs included 6 patients with hypertriglyceridemia, 4 of whom were asymptomatic; 2 patients experienced DLT thrombocytopenia (asymptomatic). Of 11 patients with response-evaluable peripheral T-cell lymphomas, two had complete responses [CR, progression-free survival (PFS) 68+ months; unconfirmed CR, PFS 14+ months], two had unconfirmed partial responses (unconfirmed PR, PFS 5 months; unconfirmed PR, PFS 6 months), and five had stable disease (2–12 cycles). One patient with mature B-cell lymphoma had an unconfirmed PR sustained for two cycles. Steady-state plasma levels were approximately 10 mcg/mL (mid-20s μmol/L) at 640 mg/m2/day, approximately 14 mcg/mL (mid-30s μmol/L) at 905 mg/m2/day, and approximately 22 mcg/mL (mid-50s μmol/L) at 1,280 mg/m2/day. Conclusions: Intravenous fenretinide obtained significantly higher plasma levels than a previous capsule formulation, had acceptable toxicities, and evidenced antitumor activity in peripheral T-cell lymphomas. A recommended phase II dosing is 600 mg/m2 on day 1, followed by 1,200 mg/m2 on days 2 to 5, every 21 days. A registration-enabling phase II study in relapsed/refractory PTCL (ClinicalTrials.gov identifier: NCT02495415) is ongoing. Clin Cancer Res; 23(16); 4550–5. ©2017 AACR.

Pegaspargase-related high-grade hepatotoxicity in a pediatric-inspired adult acute lymphoblastic leukemia regimen does not predict recurrent hepatotoxicity with subsequent doses.

Pediatric acute lymphoblastic leukemia (ALL) regimens, including higher cumulative asparaginase doses, have been investigated in adult ALL to improve outcomes. Preliminary results are promising, but hepatotoxicity rates with long-acting pegaspargase are greater in adults than children. However, adult pegaspargase-related hepatotoxicity is not as clearly defined despite being the commonest adult toxicity. We studied the frequency and characteristics of high-grade pegaspargase-related hepatotoxicity in newly diagnosed adults on a pediatric-inspired regimen that included six planned pegaspargase doses, 2000 IU/m2/dose intravenously, with doses given at least four weeks apart and not discontinued or dose-reduced for previous hepatotoxicity. Pegaspargase-related toxicity was monitored weekly after 185 delivered doses and reported by NCI CTCAE v3.0. Fifty-one patients, aged 18-57, received 192 pegaspargase doses (3.8 doses/patient). High-grade hyperbilirubinemia occurred in 16 (31.4%) patients and 23 (12.4%) doses; high-grade transaminitis occurred in 33 (64.7%) patients and 62 (33.5%) doses. Of 11 patients with high-grade hyperbilirubinemia who received at least one subsequent pegaspargase dose, six (54.5%) experienced recurrent toxicity; of 24 patients with high-grade transaminitis who received at least one subsequent pegaspargase dose, 15 (62.5%) developed recurrent toxicity. Pegaspargase at this dose and interval is associated with high hepatotoxicity rates, but patients can be rechallenged despite earlier pegaspargase-related hepatotoxicity.