FDA Approves Impavido (Miltefosine) to Treat Tropical Parasitic Disease
Most U.S. patients are infected overseas
The FDA has approved Impavido (miltefosine, Paladin Therapeutics) to treat a tropical disease called leishmaniasis.
The disease is caused by the Leishmania species of parasite and is transmitted to humans through bites from infected sand flies. The disease occurs primarily in people who live in the tropics and subtropics. Most U.S. patients acquire leishmaniasis overseas.
Impavido (miltefosine) is an oral medicine approved to treat the three main types of leishmaniasis: cutaneous, visceral, and mucosal. It is intended for patients 12 years of age and older. Impavido is the first drug approved by the FDA to treat cutaneous or mucosal leishmaniasis.
The FDA granted Impavido a “fast track” designation, priority review, and an “orphan product” designation. These designations were granted because the drug demonstrated the potential to fill an unmet medical need in a serious disease or condition; showed the potential to offer a significant improvement in safety or effectiveness in the treatment of a serious disease or condition; and is intended to treat a rare disease, respectively.
The safety and efficacy of miltefosine were evaluated in four clinical trials. A total of 547 patients received miltefosine, and 183 patients received either a comparator drug or placebo. The results from these trials demonstrated that miltefosine is safe and effective in treating visceral, cutaneous, and mucosal leishmaniasis.
The labeling for Impavido includes a boxed warning to alert patients and health care professionals that the drug can cause fetal harm and therefore should not be given to pregnant women. Health care professionals should advise women to use effective contraception during and for 5 months after treatment with Impavido.
The most common side effects identified in clinical trials were nausea, vomiting, diarrhea, headache, decreased appetite, dizziness, abdominal pain, itching, drowsiness, and elevated levels of liver enzymes (transaminases) and creatinine.
Miltefosine was originally developed as an anti-neoplastic agent. It is an alkyllysophospholipid analogue drug with in vitro activity against the promastigote and amastigote stages of Leishmania species. As an oral agent, it is registered in Germany, in several countries in South America, and on the Indian subcontinent for the treatment of cutaneous and visceral leishmaniasis. Miltefosine was included in the World Health Organization essential medicines list as an anti-leishmaniasis medicine in March 2011.
Cutaneous leishmaniasis (CL) usually presents as one or more skin ulcers at the site of a sand-fly bite. In the U.S., CL may be seen in returning travelers following exposure in endemic regions, and in American soldiers serving in Iraq, Afghanistan, or South America. In most cases, the ulcer spontaneously resolves within several months, leaving a scar. The goals of therapy are to accelerate healing, to decrease morbidity, and to decrease relapse.
In 1% to 10% of patients with CL in the New World, Leishmania disseminates from the skin to the naso-oropharyngeal mucosa, resulting in mucosal leishmaniasis and the destruction of nasal and pharyngeal structures. Death may occur due to complicating aspiration pneumonia.
Visceral leishmaniasis is characterized by fever, splenomegaly, and cytopenia. It is confirmed by the presence of Leishmania amastigotes in spleen or bone-marrow aspirates.Sources: FDA; March 19, 2014; and Briefing Document; October 18, 2013.