Encouraging Results From Immune-based Therapy Remune Phase II HIV Trials

The Immune Response Corporation, a immune-based therapy company in HIV and multiple sclerosis, announced today results from two European studies with REMUNE®, the Company’s lead HIV immune-based therapy. Results from a Phase II study conducted in Spain showed that long-term REMUNE® treatment was effective in delaying virologic failure during antiretroviral treatment interruption, according to the company’ announcement.

Following is the text of a press announcement from the company regarding the phase II study of Remune:

This study also showed a correlation to the magnitude of HIV-specific immune responses induced in studied patients. The second Phase II study, conducted in Italy, demonstrated stabilization of CD4+ cell counts as well as several positive trends in key markers believed to indicate immune responses against HIV disease in antiretroviral-naïve patients treated with REMUNE®.

“The positive virologic and immunologic trends, along with HIV-specific immune responses we are seeing in patients treated with REMUNE® in both the Italian and Spanish studies are a powerful signal for us to continue the direction of our REMUNE® clinical program. We are encouraged by these results which confirm earlier preliminary data that also demonstrated a immune response in those patients treated with REMUNE® ,” said John N. Bonfiglio, Ph.D., President and Chief Executive Officer of The Immune Response Corporation. “We look forward to sharing the detailed data with the scientific community at upcoming medical congresses.”

About the REMIT Study

The REMIT study enrolled 39 patients who had previously participated in the STIR-2102 Phase II double-blind study in Spain (Vaccine 2004; 22: 2966-73) in which they received either REMUNE® or Incomplete Freud’s Adjuvant (IFA), and then subsequently received REMUNE® in an open-label extension. For the REMIT study, the patients were randomized to receive either REMUNE® (n = 21) or IFA placebo (N = 18) at the time of discontinuation of highly active anti-retroviral therapy (HAART). Endpoints in the 48-week study measured immunologic or virologic failure of patients during treatment interruption, defined as time to reach HIV RNA viral load failure (defined as HIV RNA >55,000 copies/mL), time to reach CD4+ failure (as defined as <350 cells/), and/or time to re-initiation of HAART.

Analysis of the data was performed based on comparisons of four groups, composed of patients who had received the following treatments: 1) REMUNE® in the STIR-2102 and REMUNE® in the REMIT study (n = 9); 2) REMUNE® in the STIR-2102 and IFA in the REMIT study (n = 10); 3) IFA in the STIR-2102 and REMUNE® in the REMIT study (n = 12); and 4) IFA in the STIR-2102 and IFA in the REMIT study (n = 8). All patients received REMUNE® during the open-label extension phase between the STIR-2102 double-blind study and the REMIT study. The total number of REMUNE® injections received by the participants ranged from five to 28.

The results showed that patients who received REMUNE® in both the STIR-2102 and the REMIT study were less likely to reach a study failure endpoint in 48 weeks of observation in the REMIT study compared to the other three groups. The median number of REMUNE® doses received in this group was 27. The number of doses of REMUNE® received was identified as a prognostic factor in predicting delay of virologic failure during treatment interruption, as was baseline CD4+ count prior to initiation of antiretroviral therapy. There was also a positive correlation between magnitude of HIV-specific immune responses and ability to delay virologic failure in these patients. Those patients who continued to respond to REMUNE® and did not reach a failure endpoint in 48 weeks as defined in the study protocol are being followed for an additional 48 weeks, without receiving any additional treatment.

An independent Data Safety Monitoring Board (DSMB) that reviewed the results of the REMIT study concluded that the results support the notion that REMUNE® delays virologic failure in particular patients, and also support the notion that long-term repeated exposure to REMUNE® is of benefit. Additional analyses of immunology results and to identify other prognostic factors for success are ongoing.

About the Italian Study

The multi-center, single-blind, randomized study followed 51 patients over 28 weeks following treatment with REMUNE®, IFA or saline. Patients were antiretroviral therapy naïve and had HIV RNA levels between 10,000 and 40,000 copies/mL and CD4 counts between 400 and 800 cells/µL at study entry. Patients received three injections of REMUNE® (n=19), IFA (n=10), or saline (n=11) at weeks 0, 12, and 24. A fourth group received only a single injection of REMUNE® at week 0 (n = 11).

The final analysis included data from 51 patients enrolled in the study, and showed that median absolute CD4 cell counts remained stable through week 28 in the patients that received 3 injections of REMUNE®, but declined in both the IFA and saline groups. REMUNE®’s effect on immune reconstitution as further evidenced by an augmented serum concentration of IL-7 and increases in naïve CD4+ T cells suggests a possible mode of action via stimulation of thymus function. The researchers believe that this effect on the thymus may be important in boosting the body’s own defense against HIV. Further research is being carried out to confirm this positive effect on thymus and the circulating lymphocytes phenotypes.

Both the REMIT and Italian trials were intended to explore the potential utility of REMUNE® and neither trial was designed to have enough statistical power to be used for regulatory approval. The Company is planning a clinical program that would use the data from these two trials to design registration trials in the near future.

REMUNE® is in Phase II development by The Immune Response Corporation and is not approved by any regulatory agencies in any country at this time.

About The Immune Response Corporation

The Immune Response Corporation (Nasdaq: IMNR) is a biopharmaceutical company dedicated to becoming a leading immune-based therapy company in HIV and multiple sclerosis (MS). The Company’s HIV products are based on its patented whole-killed virus technology, co-invented by Company founder Dr. Jonas Salk, to stimulate HIV immune responses.

REMUNE®, currently in Phase II clinical trials, is being developed as a first-line treatment for people with early-stage HIV. We have initiated development of a new immune-based therapy, IR103, which incorporates a second-generation immunostimulatory oligonucleotide adjuvant and is currently in Phase I/II clinical trials in Canada and the United Kingdom.

The Immune Response Corporation is also developing an immune-based therapy for MS, NeuroVaxTM, which is currently in Phase II trials and has shown potential therapeutic value for this difficult-to-treat disease.

For more information about The Immune Response Corporation, visit www.imnr.com.

03/14/05

Source
The Immune Response Corporation www.imnr.com.

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