Tolerability of an extract of European mistletoe among immunocompromised and healthy individuals

European mistletoe (Viscum album L) has been used parenterally for more than 80 years as an anticancer medication with significant immunomodulating action. Since 1984, clinical experience with a Viscum album extract (Viscum album Quercus Frischsaft [Qu FrF]) among HIV-positive patients has suggested that it inhibits HIV disease progression.

To determine the toxicity profile and biochemical effects of a Viscum album extract.

A dose-escalating phase I/II study.

32 HIV-positive and 9 healthy participants.

Standardized for its lectin and viscotoxin content, the extract was administered subcutaneously twice weekly in gradually increasing doses for 2 to 17 weeks per dose increase. Doses of 0.01 mg to 10.0 mg were administered.

Adverse events, hematology, and biochemistry.

No severe side effects were found. During gradual dose escalation, more adverse events occurred at the lower dose range. The hazard rate of systemic adverse events was highest among HIV-positive patients. Drug-related adverse events were flu-like symptoms and transient exacerbations of gingivitis, fever, and eosinophilia. An increase of serum urea nitrogen and serum creatinine levels occurred, as did a slight decrease in total protein caused by a minor fall in albumin concentrations. Dose dependence was apparent for inflammation and fever, which may or may not have been side effects of the preparation.

Viscum album Qu FrF can be administered safely to HIV-positive patients. It induces immunomodulation in HIV-positive and healthy individuals and may inhibit the progression of HIV disease.