Development of N-tert-(Butyl)hydroxylamine (NtBuHA) as a therapeutic agent for treating Infantile Neuronal Ceroid Lipofuscinosis (INCL)

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PROJECT SUMMARY/ABSTRACT There is a significant unmet medical need for a therapy to treat patients with Infantile Neuronal Ceroid Lipofuscinosis (type CLN1 Batten Disease), for which there are (<1 in 100,000) estimated patients in the United States that have no current disease-treating options. We will begin a pre-clinical program on one small molecule that has been selected as a lead compound by a senior investigator at the NICHD, Dr. Anil Mukherjee. This small molecule, N-(tert-butyl)-hydroxylamine (NtBuHA), has been selected amongst a panel of 12 hydroxylamine derivatives for its minimal in-vitro and in-vivo toxicity profile, its solubility in aqueous solution, and its superior chemical activity in replacing deficient Palmitoyl-Protein Thioesterase 1 (PPT1) activity, that underlies the pathophysiology of INCL patients. In preparation for an IND-enabling program, we will de-risk NtBuHA by completing physiochemical analysis, DMPK studies, biodistribution studies, and pilot toxicology studies. Solubility, stability, and lipophilicity studies will be conducted in-vitro to confirm NtBuHA has adequate chemical properties prior to further in-vivo work. Plasma protein binding studies from four species (mouse, rat, dog, human) will determine thermodynamic binding parameters of NtBuHA to be used in PK analyses and that will help provide an estimation of human systemic exposure from animal data. Metabolic stability will be performed in microsomes and hepatocytes of four species (mouse, rat, dog, human) to estimate cross-species-to- human phase I and phase II metabolism, respectively. Metabolite profiling in hepatocytes of four species (mouse, rat, dog, human) will be performed to aid in the selection of toxicology species, and to identify any human specific metabolites. INCL patients are often treated with a combination of anti- epileptic, pain, and anti-spasticity medications (e.g. valproate, fentanyl, baclofen, tizanidine), thus necessitating drug-drug interaction (CYP inhibition and induction) studies that will be performed in human liver samples. We will complete PK studies in rats to determine the dose dependent pharmacokinetic parameters that are both adsorption dependent (via oral gavage route) and adsorption independent (via intravenous route), as well as to estimate both human PK parameters and dose regimen needed for pharmacological response. Dose-escalating biodistribution studies in rats will be conducted with focus on accumulation of NtBuHA within the brain, in order to determine the minimum dose required to achieve therapeutically relevant concentrations in brain tissues. A 7-day maximum tolerated dose (MTD) study will be completed to establish the therapeutic window for NtBuHA, and ensure therapeutically relevant brain concentrations can be safely achieved. The hERG, AMES and micronucleus tests will be completed as in-vitro toxicology gating studies that will aid in determining whether a phase II SBIR submission is merited. Upon the conclusion the proposed work, we will have a lead compound that is characterized for more comprehensive formulation, safety and efficacy evaluation in vivo. Upon successful completion of these studies, we intend to enter into Phase II SBIR studies that will employ GLP facilities and GMP materials, longer repeat dosing toxicity protocols in large animals, and safety studies (cardiac, respiratory, etc.), that will more precisely predict NtBuHA behavior in humans and that will support a subsequent IND application. Ultimately, we hope NtBuHA can become a marketed product that has clinically meaningful impact on INCL patients.