Development of a Novel Oral Amphotericin B Formulation (iCo-019) to treat systemic fungal and parasitic infections

The Wasan laboratory at the University of British in conjunction with iCo Therapeutics Inc. has made significant strides toward the development of a lipid-based amphotericin B formulation for oral administration. Pre-clinical and clinical studies completed to date indicate that our oral formulations is highly efficacious and exhibits low toxicity within the dosage range required in treating diseases such as systemic fungal infections and leishmaniasis.Each year in the Indian subcontinent alone, over 500,000 individuals play host to Leishmania donovani, an insidious parasite that invades macrophages, rapidly infiltrates the vital organs and ultimately leads to severe infection of the visceral reticuloendothelial system. Visceral leishmaniasis, also known as Kala-azar, is most prevalent in the weak and the young within a population. Left untreated, almost all infected individuals will die. The therapeutic arsenal against Leishmania is limited to a small number of parenterally administered agents, with daily injections of pentavalent antimony compound for 28 days being the usual course of action. Due to increasing resistance, antimonial drugs can no longer be used in many areas, including northeastern India where the incidence of Kala-azar is highest.Amphotericin B is the current secondary treatment of choice against leishmaniasis and has a 97% cure rate with no reported resistance. However, therapy with the first-generation formulation (FungizoneR) involves IV administration over a period of 30 to 40 days and is associated with infusion and drug-related side-effects (infection of the indwelling catheter, patient chills and shaking due to RBC haemolysis, dose-dependent renal toxicity, fever, bone pain, thrombophlebitis).Although lipid-based second-generation formulations exist (AbelcetR and AmBisomeR), which require a shorter course of therapy (3-5 days), are highly effective and exhibit lower toxicity when compared to FungizoneR, the cost of these formulations is a barrier to widespread use. Due to the difficult route of drug administration, toxicity issues and cost, amphotericin B is failing to reach the infected population and mortality rates continue to rise.The development of an inexpensive, safe and effective oral treatment is paramount in order to address both early and late stages of this deadly disease and drug-resistant forms of VL. This talk will highlight our current findings and future goals.


Histoplasmosis in patients with concurrent tuberculosis
• Coinfection with tuberculosis in some countries occurs in 8-15% of human immunodeficiency virus (HIV)-infected patients who have histoplasmosis • Occurs mostly in India, Latin America, etc. • Difficult treatment due to drug interactions • Oral Amp B may be beneficial with less drug resistance (prof. Denning)

Fungal Endophthalmitis
• Endogenous fungal endophthalmitis represents intraocular dissemination of a systemic fungal infection • Among the different fungal species, Candida species is the most common cause of infection, followed by Aspergillus species and cryptococcus • Hospitalized patients with candidemia reveal that 9-37% of patients developed candidal endophthalmitis • In India, fungi were isolated in 22% of culture-proven endophthalmitis • Systemic amphotericin has been the treatment of choice because of its broadspectrum coverage Other Potential Indications: Immunocompromised complications, HIV and neglected diseases

Febrile Neutropenia
• Use fluconazole as a control with a salvage therapy available • Treatment duration: treat until 2-3 days after patient is asymptomatic (will be specified)

Chronic Refractory Mucocutaneus Candidiasis (CMC)
• Persistent or recurrent candidal infection due to inherited T-cell defects • Typically, only poorly controlled with anti-fungals (azoles) • Potential for a better improvement with chronic oral Amphotericin B therapyless resistance, less drug interaction, safe

Visceral Leishaniasis (VL)
• Parasitic infection common in tropical, subtropical regions as well as Southern EU • If untreated almost always causes death • Amphotericin B IV is a standard treatment which is expensive, not tropically stable and difficult to administer • Miltefosine is the first oral treatment, with numerous side-effects Other Potential Indications: Immunocompromised complications, HIV and neglected diseases  Preliminary evidence shows efficacy against Candidiasis kidney gross morphology of an untreated and treated rat Antifungal Activity-Efficacy correlated to AUC and Biodistribution Assessment of kidney, liver and jejunum toxicity of iCo-010 compared to multiple dose Fungizone® IV

Oral Amphotericin B Formulations
Bridging Derivatives: in Beagles • "The lack of a significant difference between the pharmacokinetic parameters presented for the three formulations suggests that each is capable of delivering similar levels of amphotericin B into the plasma.
• Furthermore, the plasma levels of amphotericin B 24 hrs following repeated doses of iCo-019 and iCo-022 were similar at 56.0 ± 6.9 ng/mL and 52.3 ± 4.6 ng/mL, respectively an indication that these two formulations could deliver similar levels of amphotericin B into the plasma" • "The levels observed in some of the tissues in this study are similar to range of tissue concentrations of amphotericin B, 45 -495 ng/g tissue observed seven days following oral dosing in mice, tissue concentrations that were effective in producing a 69-96% reduction of fungal burden in a mouse model of systemic candidiasis."* CONFIDENTIAL A Phase 1a, placebo-controlled, single dose ascending study to assess the safety, tolerability, and bioavailability of Oral Amphotericin B in healthy male and non-pregnant female subjects between 18 -55 years of age.

Objectives:
Primary objective: • To evaluate the safety and tolerability of multiple dose levels of a single oral administration of oral Amphotericin B.
Secondary objective: • To assess the pharmacokinetics and bioavailability of oral Amphotericin B after a single dose oral administration.

Study Design:
• Subjects were randomized into one of four cohorts, each representing an ascending single dose of treatment: 100 mg, 200 mg, 400 mg and 800 mg.
• Each cohort consisted of eight subjects where six subjects were randomized to receive the investigational product and two were randomized to receive the placebo.
• All subjects were followed for seven days after dosing.

Clinical Phase 1a: Study Results
A Phase 1, placebo-controlled, single dose ascending study to assess the safety, tolerability, and bioavailability of Oral Amphotericin B in healthy male and non-pregnant female subjects between 18 -55 years of age.

Objectives:
Primary objective: To evaluate the safety and tolerability of multiple dose levels of a single oral administration of oral Amphotericin B • Study met its primary endpoint of safety and tolerability

Objectives:
Primary objective: • To evaluate safety and tolerability after repeated administration of 100 mg and 400 mg doses of oral Amphotericin B (iCo-019) for 10 days in healthy subjects Secondary objective: • To evaluate pharmacokinetic profile after repeated administration of oral Amphotericin B (10 days) in healthy individuals

Study Design:
• Approximately 12 healthy subjects, aged 18-55 years of age, were randomized to one of the two doses of oral Amphotericin B (100 mg or 400 mg) or a Placebo (5 subjects received oral Amphotericn B and one subject received Placebo in each cohort). Subjects were dosed for 10 days and followed for additional 5 days post-treatment. 35 Clinical Phase 1b: Study Results