APX-2039

Pfizer World Headquarters in Manhattan, New York. Credit: Coolcaesar / Wikipedia. Pfizer has acquired US-based Amplyx Pharmaceuticals to advance its expertise in infectious disease and expand its anti-infectives pipeline. Amplyx focuses on developing treatments for life-threatening diseases that affect individuals with compromised immune systems. With this deal, Pfizer gained ownership of Amplyx’s lead compound, Fosmanogepix (APX001), a new investigational asset being developed for treating invasive fungal infections. With a novel mechanism of action, this compound is designed to target fungal strains which are resistant to standard of care therapy. Fosmanogepix has the potential to become a novel therapeutic class of antifungal therapy to receive approval from the US Food and Drug Administration (FDA) in almost 20 years. Fosmanogepix is currently in Phase II clinical trials, which are analysing the safety and efficacy of its intravenous (IV) and oral formulations in treating people with invasive fungal infections caused by moulds, yeasts and rare moulds. Pfizer also gained access to Amplyx’s early-stage pipeline that comprises potential antiviral (MAU868) and antifungal (APX2039) therapies. Pfizer Hospital global president Angela Lukin said: “The Covid-19 pandemic has been a stark reminder of the devastating impact of infectious diseases, highlighting the continuous need for new anti-infective therapies to treat both emerging and difficult to treat bacterial, viral and fungal infections. “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 anti-fungal as well.” The latest acquisition comes after Pfizer made an initial equity investment as part of Amplyx’s Series C financing in December 2019. The companies have not disclosed the financial details of the deal. Last September, CStone Pharmaceuticals entered a strategic partnership with Pfizer to develop and commercialise late-stage oncology therapies in China.

The entrance to a Pfizer office in Cambridge, Massachusetts Pfizer joined an equity investment in clinical-stage Amplyx Pharmaceuticals last year to support the biotech’s development of a new antifungal for drug-resistant pathogens. On Wednesday, the pharmaceutical giant announced it has acquired the company outright. No financial terms were disclosed for the deal. The acquisition of San Diego-based Amplyx comes as the biotech evaluates its lead compound, fosmanogepix, in Phase 2 tests as a potential treatment for life-threatening fungal infections caused by a range of fungal pathogens including Aspergillus, Candida, Fusarium, and Scedosporium. Fosmanogepix is small molecule is designed to block Gwt1, a fungal enzyme that is important for anchoring a key protein needed to maintain the integrity of the fungal cell wall. The company says its drug does not block the human protein closest to Gwt1, and therefore can target fungal pathogens without harming healthy human cells. Pfizer said this new approach could add a new therapeutic class to the three classes of antifungals currently available. Amplyx is evaluating both intravenous and oral formulations of its antifungal candidate. In Phase 1 tests, both formulations were well tolerated and demonstrated safety. The company added that both formulations have a low propensity for interacting with other drugs. The company says developing both IV and oral formulations may allow for patients to continue their care, transitioning from IV dosing in the hospital to a pill version after discharge. Pfizer’s top antifungal product voriconazole, which is marketed as Vfend, accounted for $270 million in 2020 sales, a nearly 22% decline from the prior year. That drug has lost patent protection and generic versions are eating away at its market share. Vfend is part of Pfizer’s lineup of hospital-based products, which generated $7.9 billion in revenue last year. The equity financing that Amplyx announced last year was an extension of a $67 million Series C round from 2017. Last May, the company said that Pfizer and Adage Capital Management joined the financing, extending it to more than $90 million. With the acquisition, Pfizer also gains other programs in the Amplyx pipeline. MAU868, an antiviral, is in early clinical development. The antifungal candidate APX2039 is preclinical.