Immune Response Corp. on Monday defended its HIVtherapeutic vaccine after Kidder, Peabody analyst Robert Kuporsaid he was not impressed with preliminary data from Phase IIclinical trials.
On Friday, Kupor wrote that patients in the low-dose groupshowed a 10 percent decline in T4 cell counts, while patients inthe medium-dose group showed a 10 percent increase.However, he wrote, "the 'dose-response' demonstrated in thesetwo groups is rendered meaningless, in our opinion, by the factthat the third group (high-dose) exhibited declining T4 cells."T4 cell counts fell by 58 percent in this group.
"This dose-response curve is unbelievable," he wrote, and"seems far more likely to represent some kind of fluke." Kuporsaid this supposition is supported by the lack of correlationbetween the T4 results and the accompanying immunologicdata.
In addition, he said, all three groups seemed to have similarviral burden outcomes, and the company has focused on viralburden as its favored surrogate marker. "In absolute terms, allthe groups seemed to deteriorate during the trial," Kupor said.
While stressing that assessing incomplete data is risky, heconcluded that "we see no obvious evidence of either efficacyor of a dose-response curve."
The vaccine uses a whole killed virus depleted of the gp120outer envelope.
Immune Response spokesman Steven Basta said the study wasdesigned to show the vaccine's ability to stimulate bothantibody and T cell immune responses. "The study came outsuccessfully in our minds," he said.
Basta declined to discuss the specific data. "This is partialinformation, and there isn't enough data to make reasonableassumptions," he said.
The San Diego company (NASDAQ:IMNR), which is developingthe vaccine with Rhone-Poulenc Rorer Inc., plans to present afull statistical analysis of the data in July at the InternationalAIDS Conference in Amsterdam.
The company's shares lost 75 cents to $20.50. -- KarenBernstein
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