Hallux is a clinical-stage pharmaceutical company focused on developing a new topical dosage form and subungual route of administration for treating onychomycosis (toenail fungus) patients. To date, prescription treatments for toenail fungus have been either low cure rate topical products that must be applied daily to the nail plate surface for at least twelve months or oral products that are associated with systemic safety issues. 

Hallux’s mission is to provide a highly effective and safe topical product for patients with chronic onychomycosis who have had to live with this infection for years.

The company’s mission is to develop a highly effective topical product that kills fungi and enables the regrowth of clear, disease-free nail without reliance on systemic circulation. Initially, Hallux investigated terbinafine micro-inserts that were placed on the nail bed by cannula. In 2018, the company developed a new, high concentration terbinafine gel product that it believes will perform better than the solid-micro-inserts when administering drug to the nail bed subungually (under the nail plate).    

Hallux completed a phase 2 clinical study with its first subungual dosage form, the micro-insert HTS-519, in September 2018. The trial evaluated efficacy, safety, and tolerability in 30 moderate-to-severe onychomycosis patients enrolled from a podiatric clinic. In 2021, the Company will commence a similar clinical study with HSG and investigate a longer treatment duration. 



Onychomycosis is a fungal infection of the nail bed. It is commonly referred to as ‘toenail fungus’ because toenail infections constitute the majority of cases. The infection typically begins as a small yellow or white spot observed on the nail plate that eventually grows in size to cover the majority of the nail plate surface. The diseased toenail detaches from the nail bed causing further discoloration and dystrophia, a medical condition called onycholysis. 

Yellow, Infected, and Ugly Toenails

Onychomycosis is easy to identify as toenails become yellow, thick, and unsightly in appearance. As the fungus in the nail bed proliferates, the resulting damage can cause pain, difficulty in walking and wearing shoes, and social embarrassment due to the ugly appearance of the nails. Untreated onychomycosis may lead to additional serious complications for diabetics and other immune compromised patients and patients with poor circulation.  

The primary symptoms of onychomycosis (toenail fungus) are a toenail that turns yellow, thickens, cracks, and may separate from the nail bed


It is estimated that 35 million Americans suffer from onychomycosis. Toenail fungus can be contracted from exposure to a range of environments such as gym floors or swimming pools, which make it easy for the fungus to get under the nail and into the nail bed. Socks and shoes create a dark, warm, and moist environment for the fungus to grow. 



There have been many attempts to develop remedies for toenail fungus but to date the few products FDA approved are poor treatment options largely for two reasons – topical formulations deliver low cure rates because they cannot penetrate the nail plate to reach the infected nail bed in adequate concentrations to kill the fungus, or in the case of the leading oral product terbinafine (Lamisil® tablets) the agent must be taken daily for three months and can result in systemic side effects.  The three primary treatments for onychomycosis used today are: 


Lamisil® (terbinafine hydrochloride) is the most common agent used to treat toenail fungus through an ‘inside-out’ approach. Patients take a 250mg tablet every day for 12 weeks. The medicine travels through the body’s circulatory system and only a fraction of the dose reaches the toenail bed where the causative fungi reside. The package insert confirms that only 38% of people taking Lamisil achieve a complete cure and there can be drug interactions and adverse effects associated with its use. While liver toxicity is a rare side effect, patients must still consent to lab tests before each prescription can be filled to ensure that their liver is functioning properly while on the medicine. 


Jublia®, Kerydin®, and Penlac® are topical medications brushed onto the top of the toenail every day for a year in an effort to get enough drug through to the nail bed to thoroughly kill fungi and allow the regrowth of clear, healthy nail. This approach requires the medicine to penetrate three layers of hard keratinized nail plate to reach the nail bed where the fungus resides and does its damage. As expected, penetrating the nail plate is challenging and in formal clinical trials  the complete cure rates for these products ranged from only one out of five patients to as few as one out of 20 patients. Most patients don’t comply with the absurdly long 12-month daily treatment regimen, making positive clinical outcomes even less reliable. Yet, while complete cure rates are significantly lower than oral Lamisil®, topicals are still preferred by patients to avoid the risk of systemic side effects. This underscores the need for a topical therapy that delivers efficacy on the order of Lamisil® without the risk of a systemic adverse event or the burden of having to self-dose your own toes every day for a year or longer.   

Toenail debridement

This routine podiatric procedure involves trimming, thinning, and removing as much of the fungus-infected nail and debris under the nail as possible. Podiatrists are reimbursed by Medicare for up to six debridement procedures per year on their patients with onychomycosis. While debridement is helpful, it does not cure the infection which means patients must continue debridement for years without any real relief to their underlying problem. Podiatrists augment debridement by selling patients in-office dispensed OTC topicals like Formula 7 that have not undergone FDA approved clinical trials and therefore cannot make claims regarding the true efficacy of their products in treating onychomycosis.  



Hallux is focused on the subungual topical treatment of onychomycosis with a drug product administered by physician in a series of quick and easy in-office applications. The aim is to provide patients with an FDA approved treatment that is proven highly effective, safe, reliable, and convenient. 

Physician administration of HSG directly to the nail bed enables precise delivery of antifungal drug directly to the infection sites where it is needed. Taking the same drug orally requires much greater drug exposure because the agent must travel through the liver and the body’s systemic circulation before reaching the toenail bed.


Hallux first product was a biodegradable micro-insert that enabled direct, subungual administration of terbinafine at higher concentrations in the nail bed than achieved with oral delivery.


At Hallux, the goal is to develop a subungual topical dosage form that safely delivers high concentrations of terbinafine directly to the nail bed infection site leading to higher rates of complete cure and lower rates of recurrence. In doing so, the Company strives to offer patients a significant improvement over existing orals and topicals by eliminating:

  • Three months of daily pills 
  • The potential for systemic side-effects
  • The potential for harmful drug interactions 
  • The need for ineffective yet expensive topical medications that are only indicated for mild infection and must be self-applied by the patient every day for twelve months or more 

The Hallux Micro-Insert HTS-519  completed a phase 2  clinical study in moderate to severe onychomycosis patients in September 2018.