AIDS CLINICAL STUDY ENROLLMENT SHOULD BE ASSURED BEFORE EXPANDED ACCESS

AIDS CLINICAL STUDY ENROLLMENT SHOULD BE ASSURED BEFORE EXPANDED ACCESS program is initiated, Thomas Merigan, Stanford University School of Medicine, suggested at a recent meeting of the National Institute of Allergy and Infectious Diseases' AIDS Program Advisory Committee. "I believe the expanded access approach is a good policy, but it must be timed properly with respect to the licensing trials -- not implemented before the trials are filled or even begun," as was the case with DDI, Merigan suggested.

The "down side" of the "DDI treatment IND experience," according to Merigan, is that expanded access to DDI has probably delayed the licensing of DDI and DDC. Under the expanded access program, specified AIDS drugs are made available to those ineligible to enter a clinical trial with the drug. The program was launched in October 1989 with the availability of DDI.

Accrual rates in AIDS Clinical Trial Group (ACTG) trials have been slowing in recent months, Merrigan said. He pointed out that accrual rates for three of NIAID's AIDS Clinical Trial Groups trials -- ACTG 116 (DDI vs. AZT in patients with short-term or no prior AZT treatment), ACTG 117 (DDI vs. AZT trial in patients who have had long-term AZT therapy), and ACTG 118 (DDI vs. AZT in patients intolerant to AZT) -- has dropped "from a total of 40 to 60 patients per week to 11 last week entering all three trials."

Merigan also pointed out that "ACTG 119, another DDC protocol, has not really succeeded in our system, with only three of 300 patients being accrued." With "over 9,000 patients" in the expanded access program for DDI, Merrigan suggested that "it is not surprising that there has been some impact on new accruals for DDI and DDC protocols for the infected populations. However, there is an understandable tradeoff between increased access and decreased accrual rates." Merigan highlighted drug selection and development phase as the "critical issues" in determining whether expanded access has an effect on patient enrollment in clinicals.

Explaining the lag in patient accruals in the DDI trials, NIAID AIDS Program Director Daniel Hoth pointed to "a several-week interval between the time that expanded access opened and the clinical trials opened. In that interval, a tremendous backlog of patients, probably several thousand, were involved in the expanded access program."

Hoth also attributed the recent decline in DDI clinical trial accrual rates to the fact that there has been an increasing acceptance of AZT. He said more people want to receive AZT since three studies have shown that lower dose AZT is nearly non-toxic and equally effective as the original AZT dose.

"I'm not persuaded from [Merigan's] data yet that we've shown that expanded access...has been detrimental," Hoth stated. "In fact, I think we can say that the accrual to the DDI trials for the first six months is as brisk or better than any that's been seen in the history of AIDS trials."

Committee Chairman Martin Hirsch, Harvard Medical School, suggested that it might be necessary to appoint "a blue ribbon-kind of committee of people who don't have an opinion either for or against the expanded access/parallel track program, to look at the same kind of data or more data to see if there's been a negative impact on enrollment in trials." NIAID Director Anthony Fauci agreed with Hirsch that another group should look at the patient recruitment data, but maintained that "we can't underestimate what happened in that first eight weeks" of the expanded access program. The ACTG clinical trials "were ready to go but they didn't have" DDI, and "expanded access had the drug," Fauci noted. "That is absolutely diametrically opposed to parallel track. That is not a parallel track, that's a head start."