Pfizer Expands Presence in Antimicrobials with Amplyx Acquisition


Pfizer is expanding its presence in infectious diseases with the acquisition of San Diego-based Amplyx Pharmaceuticals and its lead antifungal compound Fosmanogepix (APX001). Terms of procurement were not disclosed.

Fosmanogepix is an investigational asset in development as a front-line treatment against invasive fungal infections, including Candida auris, which is highly resistant to antimicrobials and is considered one of the highest threats by the U.S. Centers for Disease Control and Prevention. 

The fungal infection immediately spreads from the contaminated patient and can infect surface areas and more. In 2019, in a New York hospital, a patient’s room had to be renovated entirely following that patient’s death. 

In addition to Candida auris, which is part of a family of Candida fungi, fosmanogepix is being assessed against other fungal infections, including Aspergillus spp, Fusarium spp, and Scedosporium sp.

In July, Amplyx announced Phase II data that showed its fosmanogepix demonstrated a treatment success rate of 80% against candida. While the deadly Candida auris only hits about 1,000 patients in the United States annually, there are more cases worldwide. 

Additionally, the broader candida bucket is about 100,000 patients per year with a 30% to 40% mortality rate, Amplyx Chief Executive Officer Ciara Kennedy told BioSpace last year.

Amplyx has assessed fosmanogepix as both an oral and intravenous treatment for invasive fungal infections in multiple Phase II programs. Fosmanogepix has demonstrated broad-spectrum activity in-vitro and has shown wide distribution to various tissues, including the brain, lung, kidney and eye. 

Each year, more than 1.5 million cases of invasive fungal infections occur globally. Some of these infections, such as Candida auris, have a high mortality rate, up to 80%. There has been no novel therapeutic class of antifungal therapies approved by the U.S. Food and Drug Administration in almost 20 years. And, there are currently only three classes of antifungal medications available, Pfizer said, which means antifungal resistance can severely limit treatment options.

Angela Lukin, Global President of Pfizer’s Hospital business unit, said COVID-19 has been a “stark reminder” of the devastating impact of infectious diseases and highlights the need for new anti-infective therapies, both bacterial and fungal infections. 

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“We are deeply committed to helping patients suffering from infectious diseases, continuously seeking opportunities to build our portfolio of anti-infective therapies. We’ve already invested in assets that, if approved, could help address drug-resistant bacterial infections and critical viral infections; with this acquisition, we look forward to progressing the development of a novel antifungal as well,” Lukin said in a statement.

In addition to fosmanogepix, Pfizer also gains Amplyx’s early-stage pipeline, including potential antiviral (MAU868) and antifungal (APX2039) therapies. MAU868, licensed from Novartis, is a potent neutralizing monoclonal antibody with activity against the BK virus. APX2039 is a novel Gwt1 Inhibitor in preclinical development as a potential treatment for cryptococcus, an invasive fungus that causes cryptococcosis.

The entire financial terms of the acquisition were not disclosed. However, Pfizer had already been an investor in Amplyx. In 2019, the company backed an oversubscribed $90 million Series C financing round at Amplyx.


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