Isavuconazole Causes Fewer Side Effects Compared With Voriconazole: ICAAC 2014

Submitted by Aspergillus Administrator on 24 September 2014

Important drug development work carried out by the University of Wurzburg and Johns Hopkins School of Medicine in the US was reported at the recent antimicrobial conference ICAAC 2014.

It had already been established that the new antifungal drug isavuconazole shows much promise for the treatment of aspergillosis. It is at least as good as existing antifungal drugs e.g. voriconazole when used to treat aspergillosis so it remained to be proven what the advantages of using this new drug might be.

This new report shows that patients given isavuconazole are less prone to side effects compared with voriconazole. This is an important issue as the rate of intolerance in patients who take antifungal drugs can be high and can lead to discontinuation of treatment.

Quoting:

Of those patients with uncontrolled cancer, 40% (70 subjects) who received isavuconazole experienced drug-related adverse events, compared with 60% (112 people) of those who received the already-licensed drug.

Of those with uncontrolled cancer who received voriconazole for their fungal infections, 24% (44 subjects) experienced problems related to the eye, compared with 15% (26 individuals) who were randomised to receive the experimental agent.

Of the 516 patients, 272 had uncontrolled malignancy, while others had cancer that was in remission, rheumatoid arthritis or HIV. Some had diabetes, a substantial number of whom had mucormycosis, Marr said.

For those subjects without an uncontrolled malignancy, 35% (25 individuals) of those on voriconazole had eye-related side effects, compared with 15% (13 patients) of those who received isavuconazole, the poster said.

The experimental drug was also associated with fewer cases of liver toxicity in patients without uncontrolled cancer. Four subjects (5%) without uncontrolled malignancy who received isavuconazole experienced liver problems compared with 14 subjects (19%) who were randomized to voriconazole.

We might conclude that there is a 40-60% reduction in severe side effects when using isavuconazole compared with voriconazole. This could be of great benefit to many patients.

In addition isavuconazole was shown to have 100% bio availability (compared with 82% bio availability of voriconazole). This means that there are likely to be fewer problems with managing drug dose when isavuconazole is taken orally – again this is an improvement likely to benefit some patients and may even make management of the drug cheaper in some cases!