Three Drugs Now in Expanded Access

As expected, Gilead Sciences has announced the start up of an expanded access program for its experimental anti-HIV agent adefovir (which now has a brand name -- Preveon). Formal physician registration will probably begin in early November, after the FDA completes its review of the program's particulars. According to Gilead's proposal, prospective enrollees will have to meet the following criteria: both a CD4 count of less than 50 and a viral load of over 30,000 copies/ml by PCR within the past two months, plus a record of failing at least two nucleoside analogs and one protease inhibitor.

Despite requiring this extensive history of failing to suppress HIV, the company still expects doctors to construct a "viable antiviral regimen from available agents" for their adefovir-receiving patients. The company further advises that such a regimen include at least one new agent that the patient has not taken previously. The new agent could be another experimental drug obtained through expanded access, such as Sustiva or abacavir (see below). This recommendation should not be taken lightly since adefovir has extremely modest activity (sustained viral load reductions of only about 0.5 log or 70%). It can only function as an adjunct to an otherwise potent drug combination, which by definition will be elusive for the individuals eligible for adefovir expanded access. (Further information on this program may be obtained by calling 1-800 GILEAD-5.)

The demand for experimental agents to treat patients with persistently high viral loads has proved to be substantial: DuPont Merck reports that it received 1,200 inquiries in the first three weeks after expanded access opened for its potent new non-nucleoside reverse transcriptase inhibitor Sustiva. Entry criteria for Sustiva are slightly more lenient than for adefovir: Applicants must have had a CD4 count of less than 50 in the last three months -- any viral load is acceptable -- and be "failing therapy or intolerant to their current treatment regimen." For more information, call 800/998-6854.

No one has actually received adefovir or Sustiva yet, but Glaxo reports that it is registering 100 people a week for abacavir (1592U89) compassionate use. Eligibility requirements for obtaining this highly active nucleoside analog are similar to those of adefovir except that the CD4 count limit is 100 rather than 50. The abacavir program is really an open-label trial that obliges participants to enroll at one of 60 sites around the country. Glaxo also has just opened a more traditional expanded access program for those with moderate to severe AIDS dementia. A pediatric expanded access program has been open since June, but so far only two children have received drug through it. For information on obtaining abacavir, call 800/501-4672.