PHASE IIB MBI 594AN STUDY VALIDATES ANTI-ACNE PROPERTIES.

Micrologix Biotech Inc. (TSX: MBI; OTC: MGIXF), Vancouver, a developer of anti-infective drugs, achieved statistically and clinically significant efficacy results from its Phase IIb study of MBI 594AN, a topical drug candidate under development as a first-in-class prescription treatment for acne.

The Phase II study was designed to evaluate acne lesion count reductions at various time points (3, 6, 9, and 12 weeks), comparing MBI 594AN (1.25% and 2.5%) with the alcohol vehicle. MBI 594AN 2.5% achieved statistically significant superiority at 6 weeks in reducing all three lesion parameters measured: inflammatory lesions (p equals 0.004), non-inflammatory lesions (p equals 0.037), and total lesions (p less than 0.001). A Physician's Global Severity Assessment, the fourth parameter measured, also resulted in clear superiority of the product as compared to the vehicle. The drug was extremely well tolerated, with no serious drug-related adverse events encountered in the study.

"The data from this Phase IIb efficacy study confirms the results achieved in the previous Phase IIa study," said David Friedland, M.D., vice president of clinical development for Micrologix. "We now have two well-controlled, double-blind human clinical trials that validate the anti-acne properties of MBI 594AN, providing us information needed to advance to Phase III studies."

Two internationally recognized dermatology experts, Stuart Maddin, M.D., an advisor to Micrologix, and Jerry Tan, M.D., commented, "These results clearly illustrate the clinical utility of MBI 594AN. The solid efficacy against inflammatory lesions is important for advancing development, and the significant reduction in non-inflammatory lesions is noteworthy. These results compare favorably with currently marketed products, both in the anti-infective and retinoid classes. There is a great need for a product such as MBI 594AN that reduces all types of lesions, addresses bacterial resistance, has an excellent safety profile, and is easy to use. These results, if maintained in future development, would make this product first-line treatment for patients with mild to moderately severe acne."

Based on these results, further development work for MBI 594AN will continue, including the design of future clinical and non-clinical studies required for NDA submission. Requirements prior to Phase III studies include product manufacturing, an end-of-Phase II meeting with the FDA, and the design of Phase III trials. It is expected that final decisions about the size, duration, and other attributes of future studies will be made in conjunction with a licensing partner and/or upon meeting with the FDA. We anticipate these activities can be completed by mid-2004, with Phase III trials commencing in the second half of 2004.

About MBI 594AN

MBI 594AN is an antimicrobial cationic peptide demonstrating rapid in vitro and ex vivo antibacterial effect against Propionibacterium acnes (the organism associated with acne). Potential advantages of MBI 594AN over currently available prescription topical acne products include rapid action, reduction of both inflammatory and non-inflammatory acne lesions, bactericidal activity with no demonstrated induction of resistance, rapidly effective against multi-resistant P.acnes, no evidence of toxicity, and ease of use. With the large, growing acne market, the increasing bacterial resistance seen with current acne therapies, and the clear need for a novel, first-in-class treatment, MBI 594AN represents a solid product opportunity for further development.

About the Phase IIb Trial

This Phase IIb trial was a randomized, double-blind, vehicle controlled, dose-ranging efficacy study in acne patients treated twice daily over twelve weeks with either the vehicle alone (a hydroalcoholic solution) or one of two dose levels of MBI 594AN (2.5% and 1.25% in the alcohol-based vehicle). The trial was conducted at nine centers in the United States and enrolled 255 patients. MBI 594AN was assessed based on: the reduction of inflammatory lesions (pustules and papules), the reduction of non-inflammatory lesions (comidones), and the reduction of total lesions, as well as a Physician's Global Severity Assessment of each patient during the study. In addition, the safety and local tolerability of the drug was assessed.

The results provided are preliminary, with further analysis required before a full evaluation is possible. The data indicate that the 2.5% active drug group was statistically superior to the vehicle at six weeks of treatment in all types of acne lesions measured, specifically reducing inflammatory lesions by 40%, an efficacy level that was maintained throughout the remainder of the study. Between six and twelve weeks, the control group receiving the vehicle alone displayed a gradual decrease in lesion counts (a placebo effect seen frequently in acne studies), making the analyses beyond six weeks not statistically significant. A clear dose response was seen between the active treatment groups, with the 1.25% group showing trends toward efficacy.

Background on Acne

It is estimated that 45 million people in the United States have acne, which is the most common skin disorder of adolescence and early adulthood (ages 15-24 years) with a prevalence of approximately 85%. The U.S. market for prescription acne medications was approximately US$1.6 billion in 2002 and is forecast to increase to US$1.9 billion by 2006. Prescription medications available for the treatment of acne in the U.S. can be divided into topical prescription therapies (approximately a US$800 million market) and systemic (oral) therapies (approximately a US$500 million market) and over-the-counter topical products. Generally, mild to moderate cases are treated with topical medications, with more severe cases being treated with systemic or a combination of topical and systemic therapies. The global market for prescription anti-acne products reached US$2.0 billion in 2001 and is forecast to reach revenues of US$3.3 billion in 2006.

Prescription drugs for acne treatment or prevention fall into three general categories: antibiotics, retinoids, and drugs that affect hormone levels. Problems exist with most of these treatment options. Antibiotics are not as useful as they once were as Propionibacterium acnes (P. acnes), the bacteria most commonly associated with acne, has developed resistance to many antibiotics. A significant market opportunity exists for an innovative, effective, and safe topical agent that has no side effects and avoids the problem of antibiotic resistance.

About Micrologix

Micrologix Biotech Inc. is engaged in the research, development, and commercialization of drugs that advance therapy, improve health, and enrich lives. The company's focus is toward anti-infective drug development with three product candidates in human clinical development, multiple product opportunities in preclinical development, and several early-stage technologies in various stages of research and evaluation.

For more information, call 604/221-9666 Ext. 241 or 1-800-665-1968 or visit http://www.mbiotech.com.