Title

Potential for a novel manganese porphyrin compound as adjuvant canine lymphoma therapy

Document Type

Article

Abstract

Purpose: Manganese porphyrins are redox-active drugs and superoxide dismutase mimics, which have been shown to chemosensitize lymphoma, a cancer which frequently occurs in dogs. This study aimed to identify critical information regarding the pharmacokinetics and toxicity of Mn(III) meso-tetrakis (N-n-butoxyetylpyridium-2-yl) porphyrin, (MnTnBuOE-2-PyP5+, MnBuOE) in dogs as a prelude to a clinical trial in canine lymphoma patients. Methods: A single-dose pharmacokinetic (PK) study in normal dogs was performed to determine the plasma half-life (t1/2) of MnBuOE. A dose reduction study was performed to establish the maximum tolerated dose (MTD) of MnBuOE. The safety and PK of a multi-dosing protocol was assessed. Results: Peak plasma drug concentration occurred 30 min post-injection. The t1/2 was defined as 7 h. MnBuOE induced an anaphylactic reaction and prolonged tachycardia. The MTD was defined as 0.25 mg/kg. The dogs were given MTD 3×/week for 2–3 weeks. The highest recorded tissue drug levels were in the lymph nodes (4–6 μM), followed by kidney and liver (2.5, 2.0 uM, respectively). Conclusions: We obtained critical information regarding the PK and toxicity of MnBuOE in dogs. The acute drug reaction and tachycardia post-injection have not been described in other species and may be specific to canines. The high tissue drug levels in lymph nodes have not been previously reported. MnBuOE accumulation in lymph nodes has important implications for the utility of adjuvant MnBuOE to treat lymphoma. With MnBuOE lymph node accumulation, reduction in the dose and/or administration frequency could be possible, leading to reduced toxicity.

Keywords

Canine, Lymph node, Lymphoma, Manganese porphyrin

Publication Date

8-1-2017

Publication Title

Cancer Chemotherapy and Pharmacology

ISSN

03445704

E-ISSN

14320843

Volume

80

Issue

2

First Page

421

Last Page

431

PubMed ID

28685347

Digital Object Identifier (DOI)

10.1007/s00280-017-3372-z

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