Treatment Options for IA, Mucormycosis Expanding

Having effective and safe options to treat invasive aspergillosis (IA) and invasive mucormycosis are key as these infections in patients with cancer remain an important cause of morbidity and mortality.

The development of mold-active azoles has led to enormous advancements in both prevention and treatment of invasive fungal infections, and stratifying patients by risk, either high or low risk of invasive fungal infections, can help to guide treatment decisions.

Available antifungal agents include polyenes, echinocandins, and for more than a decade now, the triazoles have been available. The data about most of these agents as they related to treating invasive mucormycosis are limited. One of these triazoles, however, has been approved within the past 2.5 years, isavuconazole (Cresemba, Astellas Pharma), and the data about this antifungal are demonstrating efficacy against mucormycosis.

During an Astellas Pharma-supported product theatre at the American Society of Health System Pharmacists Midyear Clinical Meeting and Exhibition held in Orlando, Jason Gallagher, PharmD, who is Clinical Professor at Temple University School of Pharmacy, discussed antifungal options for fungal infections.

Approved in 2015, Cresemba was FDA-approved for treating invasive aspergillosis and invasive mucormycosis. That approval was based on 2 studies: a comparative clinical trial of patients who received either isavuconazole or voriconazole for invasive aspergillosis, and an open-label study of patients with mucormycosis.

According to a paper on those studies, “clinical responses occurred across the range of isavuconazole MICs and trough levels observed,” implying that pharmacokinetic monitoring is not necessary.¹ Echinocandins are ineffective against infections caused by Mucorales and are approved as salvage therapy for refractory IA.

In an interview after the talk, Gallagher noted that voriconazole-resistant organisms have become more of a problem as clinicians use this product for prophylaxis and as generic options have become available, which prompts the need for additional treatment options as breakthrough fungal infections occur.

Toxicities are agent specific, according to Dr. Gallagher. According to a review, the most common adverse events associated with isavuconazole were gastrointestinal.¹

“The most important thing [for pharmacists to know] is to know the differences between the antifungals so they can best counsel patients about use,” Dr. Gallagher explained.

References

• Donnelly M, Zhu E, Thompson G. Isavuconazole in the treatment of invasive aspergillosis and mucormycosis infections. Dovepress. 2016; 9:79-86.