Pfizer Acquires Amplyx to Grow Anti-Infective Therapies Pipeline

Pfizer recently announced that it has acquired Amplyx Pharmaceuticals to expand its anti-infective therapies pipeline. 

Amplyx’s lead compound, Fosmanogepix, is a novel investigational antifungal that is currently under development for the treatment of invasive fungal infections. Fosmanogepix has the potential to target fungal strains resistant to standard of care therapy. 

With the acquisition, Pfizer has also secured ownership of Amplyx's early-stage pipeline that includes potential antiviral and antifungal therapies.

“We are deeply committed to helping patients suffering from infectious diseases, continuously seeking opportunities to build our portfolio of anti-infective therapies,” Angela Lukin, global president of Pfizer Hospital, said in the announcement.  

“We’ve already invested in assets that, if approved, could help address drug-resistant bacterial infections and critical viral infections,” she continued. “With this acquisition, we look forward to progressing the development of a novel antifungal as well.” 

Fosmanogepix is currently In Phase 2 clinical trials evaluating the safety and efficacy of both intravenous and oral formulations for the treatment of patients with life-threatening fungal infections caused by mold, yeasts, and rare molds. 

In July 2020, Amplyx announced that Fosmanogepix met its primary efficacy endpoint in a Phase 2 trial, with a success rate of 80 percent. There were no reported serious adverse events or discontinuations. 

The antifungal has also demonstrated broad-spectrum activity in-vitro and has shown wide distribution to various tissues including the brain, lung, kidney, and eye. 

Due to the positive trial results, Fosmanogepix may allow for the transition from IV or oral, which would enable the continuation of treatment outside of the hospital setting. 

The acquisition of Amplyx follows an initial equity investment by Pfizer in December 2019 as part of Amplyx’s Series C financing, a Pfizer spokesperson explained. 

At that time, Pfizer joined biotechnology investors that included Adage Capital Management, Arix Bioscience, BioMed Ventures, New Enterprise Associates, Pappas Capital, RiverVest, and Venture Partners. 

According to data from the National Institutes of Health, more than 1.5 million cases of invasive fungal infections occur worldwide each year, with mortality rates ranging from 30 to 80 percent across various infection types. 

Currently, there are just three classes of antifungal medications currently available, including azoles, polyenes, and 5-fluorocytosine. But no novel therapeutic class of antifungal therapies have been FDA approved in nearly 20 years.

New antifungal drugs with better drug characteristics are vital. This includes antimicrobial resistance, which has emerged in Candida and Aspergillus, as well as innate-resistance that exists in Scedosporium, Lomentospora prolificans, Fusarium, and Mucorales fungi.

But existing antifungal drugs can be difficult to adequately dose, due to toxicities, drug interactions (like cancer agents), poor oral adsorption, and/or lack of exposure in some tissue compartments.

The development of antifungal drugs has unique challenges, as well. 

For example, antifungal clinical trials have issues recruiting patients due to the relatively small number of patients with a specific invasive fungal infection. Trials in invasive fungal infections are highly complex, taking a long time to conduct and requiring more resources. 

Most recently, clinical trials are being conducted in patients with limited or no treatment options, which should increase the number of patients eligible for the trials. High enrollment costs can also discourage sponsors and investors from developing antifungal drugs.

A potential new therapeutic class may therefore be of importance for both physicians and patients. 

“Modern medicine is able to successfully treat diseases that only a few years ago were universally fatal. However, these lifesaving treatments make the patient high risk and vulnerable to invasive fungal infections,” an FDA spokesperson said in a statement. 

“Currently, such patients are poorly served as they have limited antifungal drug treatment options. There remains a high need for new and novel mechanisms of action for antifungal drugsable to successfully treat life threatening fungal infections,” they continued.