Arimoclomol for Niemann-Pick Disease Type C - An Insight

Overview:

There is hope regarding Arimoclomol in the context of NPC. As per the results of one of the trials, Arimoclomol reduced the rate of disease progression by 65 percent compared to a placebo, which meant that in some individuals, it stabilized the severity of the disease. Adverse events were predominantly acceptable, and major events were less frequent due to Arimoclomol than placebo. Arimoclomol has potential as an NPC drug: such significant treatment effect concomitantly with great tolerability. The United States Food and Drug Administration (USFDA) approved Arimoclomol for Niemann-Pick disease type C on September 20th, 2024.

Drug Group:

Known to be categorized as a heat shock protein (HSP) inducer, the pharmaceutical compound Arimoclomol acts as a drug that increases the response of heat shock in cells while promoting the regulation of misfolded proteins and stimulation of lysosomal activity. Arimoclomol has already emerged as a very promising compound for patients with NPC, whose administration significantly slows down the progression and, in some cases, stabilizes the severity of the disease. The drug was shown to enhance myelination, reduce lysosomal storage, and improve the transport of mutant proteins in NPC and other neurodegenerative diseases.

Dosages:

Dose recommendation for oral formulation of Arimoclomol used with Miglustat of patients whose actual body weight is :

• 8 kg to 15 kg(kilograms), is 47 mg(milligrams) three times a day, or> 15 kg to 30 kg, is 62 mg three times a day.

• For patients weighing 30 kg to 55 kg, it is 93 mg three times a day; for patients greater than 55 kg, it is 124 mg three times a day.

For Patients:

What Is Niemann-Pick Disease Type C?

Niemann-Pick disease type C is a rare genetic disorder in which decreased intracellular lipid movement results in cholesterol and other lipids accumulation within cells. It is classified as type C (NPC). Since the NPC1 or NPC2 gene mutation causes a change in cholesterol transport, many symptoms arise, including intellectual deterioration, ataxia (loss of muscle control due to neurological signs), and neurological incapacitation. Cases of this mostly occur in children but sometimes emerge in adults. Because the disease is complex and few diseases have modifying treatment, it becomes challenging to identify and treat.

What Is the Management of Niemann-Pick Disease Type C?

The cure for NPC calls for an integrative approach to its treatment. As far as the management of neurological disorder is concerned, along with physical therapy, the use of analgesic painkillers and the glucosylceramide synthase inhibitor Miglustat is made to reduce the production of glucocerebroside in the case of NPC. Recent work also explores the potential utility of 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) in stabilizing NPC progression. The sooner the treatment initiation and closer the follow-up in specialty centers, the better.

How Does Arimoclomol Work?

Arimoclomol is an HSP co-inducer that targets misfolded proteins, enhances lysosomal function, and amplifies the heat shock response. Due to the induction of HSP, it facilitates the elimination of misfolded proteins, lowers protein aggregation, and reduces cellular stress. This therapeutic approach protects neurons, maintains neuromuscular functions, and stabilizes the course of neurodegenerative diseases like ALS (amyotrophic lateral sclerosis)(brain and spinal cord nerve cells are damaged) and NPC.

What Must the Patient Inform the Doctor Before Taking Arimoclomol?

Patients should inform their physician concerning any existing medical condition, continued therapies, allergic conditions, and medications they are on before starting Arimoclomol. The patient should particularly state if any previous episodes of allergic reactions to liver or renal disease have occurred and if the patient is either pregnant or a nursing mother. Additionally, the patient should inform his or her doctor about other supplements or over-the-counter drugs being taken so that no interactions occur with Arimoclomol.

What Are the Side Effects of Using Arimoclomol for Niemann-Pick Disease Type C?

• Hives.

• Rash.

• Stuffy nose and sneezing.

• Diarrhea.

• Weight loss.

• Tremors.

• Headache.

• Seizures.

For Doctors:

Description:

• Arimoclomol citrate is an active ingredient in Arimoclomol capsules. It appears as an off-white or white crystalline powder freely dissolved in water.

• Chemical Name: N-[(2R,Z)-2-hydroxy-3-(1-piperidyl)propoxy]pyridine-3-carboxylic imidoyl chloride, 1-oxide, citrate.

• Empirical Formula: C20H28ClN3O10.

• Molecular Weight: 505.90 g/mol(gram per mole) of Arimoclomol.

• Inactive Ingredients: Magnesium stearate, microcrystalline cellulose (MCC). The inactive substances do not dissolve if the capsule's contents are mixed with drinks or soft foods because the inactive substances do not dissolve in water.

Dosage Forms:

Capsules: 47 mg (milligrams), 62 mg, 93 mg, and 124 mg of Arimoclomol.

Indications:

Arimoclomol, combined with Miglustat, is indicated for treating neurological symptoms associated with Niemann-Pick disease type C in adults and pediatric patients two years of age and older.

Contraindications:

Hypersensitivity responses, such as urticaria and angioedema, have occurred during clinical studies in the first two months of treatment. If severe hypersensitivity reactions occur, withdraw the product. Discontinue treatment with Arimoclomol and treat the mild or moderate hypersensitivity reaction immediately. Monitor the condition until signs and symptoms have dissipated.

Warnings and Precautions:

• Hypersensitivity Reactions: Angioedema and urticaria cases have been reported. Arimoclomol should be withdrawn from patients who experience these hypersensitivity reactions.

• Embryo Fetal Toxicity: Causes potentially toxic effects on the developing fetus. Counsel pregnant women on the potential effects on the unborn infant and advise them on preparations to avoid such damage.

• Elevated Creatinine with Preservation of Glomerular Activity: In most studies, serum creatinine was increased by ten percent to 20 percent due to post-dialysis elevations. Alternative measurements of renal function should be done employing non-creatinine-based measures.

What Are the Adverse Reactions of Arimoclomol?

The most common adverse reactions (≥15%) are upper respiratory tract infection, diarrhea, and decreased weight.

• Urticaria (itchy welts on skin due to allergic reactions).

• Angioedema (sudden, localized swelling in the deeper layers of the skin or mucous membranes).

• Bradycardia (slow heart rate, typically less than 60 beats per minute).

• Decompensated heart failure (the heart cannot pump blood effectively, leading to fluid buildup in the lungs and other body parts).

• Cardiac arrest and heart block.

• Gastrointestinal issues.

• Elevated transaminases (enzymes that catalyze the transfer of amino groups between amino acids and oxoacids).

• Tubulointerstitial nephritis (inflammation in the kidney tubules and interstitium).

What Are the Pharmacological Aspects of Arimoclomol?

1. Mechanism of Action: Arimoclomol increases the induction of heat shock proteins (HSPs) and increases the heat shock response during stress on the cells. The technique has been known to assist cells in overcoming problems relating to protein misfolding, aggregation, and degradation, which are manifestations in neurodegenerative diseases such as NPC and ALS. Arimoclomol is a promising drug that could ease ALS, IBM, and NPC through protein homeostasis that may alter the course of the disease.

2. Pharmacodynamics: Arimoclomol reduces protein misfolding and aggregation by increasing the level of heat shock proteins, like HSP70. Hence, it is also used for the treatment of neurodegenerative diseases, such as ALS and NPC. Attributed to its property of changing disease, it hits multi-disease pathways such as inflammatory stress, protein aggregation, and synaptic dysfunction. Studies on ALS and NPC show it is safe and effective and elicited a high degree of clinical disease stability, and annual progression was reduced by 65 percent.

3. Pharmacokinetics: Arimoclomol presents with dose-linear exposures, a constant half-life, and increased levels of CSF following a dosage increase. Its excellent penetration through the blood-brain barrier allows administration thrice daily. It has been investigated to be safe and well tolerated in patients with ALS and NPC. In these patients, there was significant stability in the disease condition, with a drop in yearly progression by 65 percent. The pharmacokinetic properties confer the potential disease-modifying activity of Arimoclomol in neurodegenerative diseases.

• Absorption: The bioavailability of Arimoclomol was not determined through oral dosing.

• Effect of Food: The effect on the pharmacokinetics of Arimoclomol was not clinically relevant following a high-fat meal.

• Distribution: The mean apparent volume of distribution at the steady state of Arimoclomol is 211 L in healthy adult subjects. At a steady state, there was a dose-dependent increase in the levels of Arimoclomol in cerebrospinal fluid.

• Elimination: The elimination half-life of Arimoclomol is estimated at around four hours.

• Metabolism: Glutathionylation, O-glucuronidation, and NO-oxime cleavage are major metabolic pathways that degrade Arimoclomol.

• Excretion: After a 100 mg dose of radiolabeled Arimoclomol was given to healthy male volunteers, about 12 percent of the dose was excreted in feces and approximately 77.5 percent through urine, of which 42 percent was excreted unchanged after fasting.

Drug Interactions:

Substrates of the Organic Cationic Transporter 2 (OCT2): Look for adverse reactions and reduce the dosage of the OCT2 substrates.

• Dalfampridine.

• Dofetilide.

• Memantine.

• Metformin.

• Pindolol.

• Pramipexole.

• Procainamide.

Use in Specific Populations:

• Pregnancy: Findings of animal studies on the topic of reproduction also reveal that Arimoclomol can pose a risk to the developing fetus when it is given to pregnant females. Currently, there is no data relating to the use of Arimoclomol in pregnant females as well, further due to the drug causing serious congenital anomalies, miscarriage, or other severe effects for the mother or the developing fetus. Include a warning of this potential threat to the developing fetus for all female patients who are pregnant.

• Lactation: No data is available on the excretion of Arimoclomol into human or animal milk, its effects on the breastfed infant, or its impact on milk supply. In addition to the mother's clinical need for Arimoclomol and the potential adverse effects of Arimoclomol or underlying maternal condition on the breastfed neonate, the benefits of nursing for growth and health must be considered.

• Pediatrics: The safety and effectiveness of Arimoclomol have not been established in pediatric patients younger than two years of age.

• Geriatrics: Most NPC patients are in their youth and early adulthood. Clinical trials in patients with NPC and using Arimoclomol with Miglustat did not enroll patients aged 65.

• Females and Males of Reproductive Potential: Based on research, Arimoclomol may impair fertility.

• Renal Impairment: The recommended less frequent dosing of the combination of Arimoclomol and Miglustat is lower in patients with an eGFR of 15 mL/minute to less than 50 mL/minute(milliliter per minute) compared to that suggested for subjects with normal renal function. The recommended dosing of the combination of Arimoclomol and Miglustat in patients with an eGFR ≥ 50 mL/minute is the same as in patients with normal renal function. Plasma concentrations of Arimoclomol in the subgroup of patients with eGFR ≥ 15 mL/min increased to <50 mL/min. Pharmacokinetics of Arimoclomol in patients with an eGFR < 15 mL/minute have not been studied.

Clinical Studies:

Trial 1 is a randomized, double-blind, placebo-controlled study of 12 months in patients with confirmed Niemann-Pick disease type C (NPC), aged between two to 19 years. Patients were randomly allocated to receive Arimoclomol at a dose of three times daily, in doses of 31 to 124 mg or placebo; randomization was stratified by prior treatment status of the patient with Miglustat.

The rescored 4-domain NPC Clinical Severity Scale determined efficacy, which assesses fine motor, swallowing, ambulation, and speaking capabilities. Patients were assessed at baseline and then at three-month intervals for one year.

Among the participants, 76 percent (Arimoclomol group) and 81 percent (placebo group) received Miglustat for six months or more before their enrollment. The sub-group receiving Miglustat had an average age of 11.6 years at study entry and had symptoms since an average of 8.5 years with neurological manifestations at an average age of 4.9 years. Patients in the sub-group were 87 percent White and 56 percent female.

The Arimoclomol group had a higher mean R4DNPCCSS score at baseline than the placebo group, with a mean score of 8.9 versus 7. Three and one in the Arimoclomol Group left because of an adverse event and a withdrawal of consent, respectively. In contrast, one patient left the placebo group because of an adverse event.

The study offers the mean changes over time by treatment group and reports the data on the changes in the scores of R4DNPCCSS in patients who received Miglustat from baseline through month 12.