NTZ: Cryptosporidiosis New Treatment

A new drug which may be the best cryptosporidiosis treatment yet is now in small clinical trials. And a compassionate-access program has been announced by developer UNIMED Pharmaceuticals, Inc.

We first heard about NTZ (nitazoxanide) from a physician we know, who believes he acquired the parasite when public water supplies in the San Francisco area were heavily contaminated last winter. He received the drug by volunteering for a small trial in Mexico City. At first it did not work; he had to increase the usual starting dose (500 mg twice a day). Now the cryptosporidiosis, which had been serious enough to require TPN for several months, is largely controlled although not cured; stool tests are usually negative, but occasionally some diarrhea returns and stools become positive again. Although a course of treatment often lasts only 14 days, he has been on the drug for several months.

All 14 of the people in the Mexico City trial had their stools become negative for cryptosporidiosis. We do not know how many of them have continued with maintenance treatment.

NTZ can cause side effects of nausea and vomiting, so it is usually taken with a small amount of food. NTZ appears to be effective against many intestinal parasites; over 1,000 people have taken the drug so far, almost all outside the United States. UNIMED recently started a phase III trial for persons with AIDS in Mexico.

In the U.S., a small study is now recruiting at Cornell Medical Center in New York City, and possibly at a second site in San Francisco. Those enrolled will be randomly assigned to 14 days of treatment with 500, 1000, 1500, or 2000 mg per day, with 14 and 28 day additional courses of treatment available for those who do not have a complete response.

Also, a compassionate access program has been announced for those who cannot participate in the controlled study, due to eligibility restrictions or geography. But this program has only 30 slots, and is almost completely enrolled. It is open for persons ages 3-65, with exclusions for current infection with a number of other intestinal parasites, history of intestinal MAC or intestinal KS, concomitant use of other drugs to treat cryptosporidiosis or microsporidiosis, and some other exclusions.

We do not know of any other way to get NTZ at this time.

For more information about the trial or the compassionate access program, call Sandy Faulkner, R.N., 800/864-6330, 8-5 Central Time.

Comment

The number of slots in the expanded-access program is clearly inadequate, and certain to become an issue unless it is increased.

We have heard that the cost of producing NTZ is very low. The cost of administering a large expanded-access program could be significant. But the FDA has regulations to allow companies to charge to recover this cost. The developer could be reimbursed for any costs, and hire a contractor if necessary to administer the program.

If the program is limited because of safety concerns about a new drug, then the FDA should re-examine the risks vs. benefits. Many people die from cryptosporidiosis, and there is no approved or satisfactory treatment. The fact that all 14 participants in an early trial became negative in stool tests implies that NTZ can at least control the disease for some period of time in a great majority of cases. A thousand people have used this drug; unless there is some major safety concern we do not know about, the risks of a larger program are clearly worth taking.