Michael Chiarella

Pharmacokinetics of CPX-351; a nano-scale liposomal fixed molar ratio formulation of cytarabine:daunorubicin, in patients with advanced leukemia

Forty-eight patients received CPX-351 (liposome-encapsulated cytarabine:daunorubicin at a 5:1 molar ratio) every other day for 3 doses at 10 dose levels. Pharmacokinetic parameters were dose-independent and exhibited low inter-patient variability. CPX-351 showed a negligible distribution phase and prolonged mono-exponential first-order plasma elimination (t(1/2)∼24 h). The plasma ratio of 5:1 was maintained at all dose levels. Nearly all of the detectable cytarabine and daunorubicin in circulation following CPX-351 administration was in the form of liposome encapsulated drug. Dose-dependent hematopoietic effects had early onset with cytopenias at 12 units/m(2), and a gradual increase in frequency and severity, until single induction complete response was achieved at 43 units/m(2). Non-hematologic effects had onset by 24 units/m(2) with shallow dose-response until maximum frequency and severity were observed at the 101-134 units/m(2) dose levels. Single induction response occurred over a 2.3-fold range of doses indicating that CPX-351 may be useful at high doses for patients suitable for intensive chemotherapy and at reduced doses for patients at increased risk of treatment-related mortality. The unique pharmacologic features of CPX-351 contribute to its promising antileukemic efficacy.

CPX-351 (cytarabine and daunorubicin) Liposome for Injection Versus Conventional Cytarabine Plus Daunorubicin in Older Patients With Newly Diagnosed Secondary Acute Myeloid Leukemia

Purpose CPX-351 is a dual-drug liposomal encapsulation of cytarabine and daunorubicin that delivers a synergistic 5:1 drug ratio into leukemia cells to a greater extent than normal bone marrow cells. Prior clinical studies demonstrated a sustained drug ratio and exposure in vivo and prolonged survival versus standard-of-care cytarabine plus daunorubicin chemotherapy (7+3 regimen) in older patients with newly diagnosed secondary acute myeloid leukemia (sAML). Patients and Methods In this open-label, randomized, phase III trial, 309 patients age 60 to 75 years with newly diagnosed high-risk/sAML received one to two induction cycles of CPX-351 or 7+3 followed by consolidation therapy with a similar regimen. The primary end point was overall survival. Results CPX-351 significantly improved median overall survival versus 7+3 (9.56 v 5.95 months; hazard ratio, 0.69; 95% CI, 0.52 to 0.90; one-sided P = .003). Overall remission rate was also significantly higher with CPX-351 versus 7+3 (47.7% v 33.3%; two-sided P = .016). Improved outcomes were observed across age-groups and AML subtypes. The incidences of nonhematologic adverse events were comparable between arms, despite a longer treatment phase and prolonged time to neutrophil and platelet count recovery with CPX-351. Early mortality rates with CPX-351 and 7+3 were 5.9% and 10.6% (two-sided P = .149) through day 30 and 13.7% and 21.2% (two-sided P = .097) through day 60. Conclusion CPX-351 treatment is associated with significantly longer survival compared with conventional 7+3 in older adults with newly diagnosed sAML. The safety profile of CPX-351 was similar to that of conventional 7+3 therapy.

Unsatisfactory efficacy in randomized study of reduced-dose CPX-351 for medically less fit adults with newly diagnosed acute myeloid leukemia or other high-grade myeloid neoplasm

The need for new therapies for medically less fit adults with acute myeloid leukemia (AML) is unquestioned.[1][1] CPX-351, a liposomal formulation of cytarabine and daunorubicin,[2][2] may be an attractive option. In patients with relapsed/refractory leukemia, in whom CPX-351 was administered on

Abstract 1292: Pharmacokinetics of CPX-351: A nano-scale liposomal fixed molar ratio of cytarabine-daunorubicin (Cyt:Daun) in patients with advanced leukemia

Proceedings: AACR 102nd Annual Meeting 2011‐‐ Apr 2‐6, 2011; Orlando, FL Background: CPX-351 is a liposomal formulation that co-encapsulates Cyt and Daun enabling delivery of both drugs at a synergistic 5:1 molar ratio. A Phase I study in advanced AML patients demonstrated substantial efficacy with complete remissions (CRs) and acceptable safety. The MTD was 101 units/m2. One unit of CPX-351 contains 1 mg Cyt and 0.44mg of Daun. Here we examine the PK of CPX-351 as a function of dose, inter-patient variability and patient characteristics in order to identify potential PD relationships. Methods: 35 male and female patients with advanced hematologic malignancies were included in the PK portion of this Phase I trial and received 24, 32, 43, 57, 76, 101, or 134 units/m2 of CPX-351 by IV infusion over 90 minutes on Days 1, 3, and 5. Validated LC/MS/MS assays were used for determination of total plasma Cyt and Daun. PK parameters [Cmax, AUC, t1/2, Vss, CL, Cmax/Dose, AUC/Dose] were determined on Days 1 and 5. Results: Mean Cyt and Daun PK parameters are presented in the [table below][1]. No significant differences were observed in t1/2, Vss, CL, Cmax/Dose, or AUC/Dose among dose groups on either study day, although some drug accumulation was observed from day 1 to day 5. Cyt and Daun PK parameters were not correlated with patient gender, age or race. Incidence of non-hematologic toxicity increased with dose and systemic exposure. CRs were observed in patients receiving doses of 32-134 units/m2 of CPX-351. The responses at 101 units/m2 and above appear to be more durable. The Cyt:Daun molar ratio remained near 5:1 for up to 48 hours on both study days for all dose levels. Conclusions: Cyt and Daun delivered in CPX-351 exhibited linear single dose and multiple dose PK and low inter-patient variability in plasma concentrations within dose groups. CPX-351 provides predictable, extended systemic exposure of elevated Cyt:Daun concentrations near a 5:1 molar ratio. The 100 unit/m2 dose is undergoing testing in Phase II studies. ![Figure][2] Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1292. doi:10.1158/1538-7445.AM2011-1292 [1]: #F1 [2]: pending:yes