Microbion Announces Positive Topline Results from Phase 2 Study of Topical Pravibismane for Moderately Infected Diabetic Foot Ulcers

• Study achieves primary endpoint, demonstrating safety and tolerability of 12-week treatment regimen with high-concentration of topical pravibismane
• High patient compliance observed with at-home self-treatment
• Data demonstrated a numerical treatment benefit across multiple efficacy measures, including full wound closure, despite study not being powered for statistical efficacy

BOZEMAN, Mont. and VANCOUVER, BC, Nov. 13, 2024 /PRNewswire/ - Microbion Corporation today announced positive topline safety and efficacy results from its recently completed Phase 2 study of topical pravibismane for diabetic foot ulcer infections (DFI). The study was designed to assess the safety and tolerability of a 3-times per week dosing, 12-week treatment regimen of topical pravibismane applied both at home, and in out-patient wound care clinics.

Safety and Tolerability

The study met its primary objective of safety, demonstrating a favorable safety and tolerability profile over the 12-week treatment period and 4-week follow-up.

• No adverse events attributable to topical pravibismane
• No treatment discontinuations due to drug-related intolerability
• PK data showed no evidence of systemic pravibismane exposure or accumulation
• Pravibismane had no observable effects on vital signs, clinical chemistry, hematology, ECG parameters, or other laboratory findings

Efficacy Signals

While not powered for statistical efficacy, the study showed promising trends favoring topical pravibismane plus standard of care (SoC) evaluating exploratory efficacy endpoints including complete wound closure, time to complete wound closure, and reduction in wound size when compared to SoC alone.  

"We are excited to build upon the topical pravibismane story with another successful clinical study," said Dr. Brett Baker, Microbion's President and Chief Innovation Officer. "We demonstrated the safety and feasibility of a much longer duration regimen and a higher drug concentration with over half of the treatments being self-administered by patients at home. The clinical efficacy signals further confirm topical pravibismane's potential for achieving complete wound closure in chronic, long-standing wounds that are otherwise not responding to the current standard of care.  Importantly, patient compliance with the pravibismane treatment regimen, the majority of which took place unsupervised at home, was excellent.  Topical pravibismane has now consistently been shown to be safe and well-tolerated in six clinical studies involving over 350 human subjects. We would like to thank the investigators and patients who have made this trial a success as novel therapies are greatly needed to address the significant unmet medical needs of patients with chronic, non-healing diabetic ulcers."

"We are extremely pleased that topical pravibismane succeeded in meeting the primary safety objectives of this study, in this complex patient population, which now enables us to plan for convenient dosing treatment regimens in pivotal studies," said Dr. Wayne Dankner, Microbion's medical consultant and the study's medical monitor. "Pravibismane has been shown to be safe and tolerable for 12-weeks of treatment, which allows for the necessary time for certain chronic diabetic wounds to heal with the convenience of at home application. The multiple activities demonstrated by topical pravibismane, including broad spectrum antimicrobial, antibiofilm, and anti-inflammatory activities may facilitate the healing and resolution of diabetic foot ulcers with a single agent when normally several different treatment modalities are necessary.  I am not aware of any other approved drug for the healing of infected diabetic foot ulcers that has the range of activities that pravibismane has exhibited to date." 

In addition to the positive clinical safety results and numerical efficacy trends of this study, pravibismane's potency against a broad-spectrum of drug-resistant bacterial isolates collected from subjects throughout the course of the study was re-confirmed. All infections treated in this study were comprised of multiple bacterial species. Importantly, all bacteria considered to be key pathogens in diabetic foot ulcers in this study, including those resistant to one or more antibiotics, were sensitive to pravibismane.

This Phase 2, randomized, controlled, multi-center, exploratory open-label study, enrolled 46 subjects (~2:1 randomization) with moderately infected, chronic diabetic foot ulcers in the outpatient wound care clinic setting. This study compared the administration of topical pravibismane in addition to standard of care (N=30) treatment for up to 12 weeks versus standard of care alone (N=16).  The study's main objective was to assess the safety and tolerability of topical pravibismane at higher concentrations than previous clinical trials and for a longer treatment duration of 12-weeks. The secondary objectives were to explore key signals of efficacy demonstrated in an earlier clinical study and assess the operational feasibility of at home administration of topical pravibismane.¹ ClinicalTrials ID: NCT05174806.

Diabetic foot ulcers (DFU) and infections (DFI) are an area of critical unmet need in the United States. Approximately 1.6 million Americans develop a diabetic foot ulcer (DFU) each year, with approximately 20% of infected ulcers leading to lower-extremity amputation.^2,3 The five-year mortality rate for DFU is comparable to all cancers, at approximately 30%, and increases dramatically with amputation.³ The estimated direct cost of care for diabetic foot disease is nearly equal to the costs for cancer in the US at ~$80B annually.³ Infected diabetic foot ulcers are complicated by the involvement of multiple species of bacterial pathogens and their biofilms, as well as chronic, unresolving inflammation.

Pravibismane has demonstrated unique potential to address this unmet need via multiple novel modes of activity that enable potent-broad spectrum antimicrobial activity against a wide range of bacterial and fungal pathogens (including multidrug-resistant), the ability to eradicate biofilms, and a direct anti-inflammatory effect.  This study was funded, in part, by an award from the Naval Medical Research Command (NMRC)- Naval Advanced Medical Development (NAMD) to CUBRC, Inc. through the Medical Technology Enterprise Consortium (MTEC) under Other Transactions Authority (OTA) Number W81XWH-15-9-0001.

References:

1. Lipsky BA, Kim PJ, Murphy B, McKernan PA, Armstrong DG, and Baker BHJ. Topical pravibismane as adjunctive therapy for moderate or severe diabetic foot infections: A phase 1b randomized, multicenter, double-blind, placebo-controlled trial. Int Wound J. 2024;21:e14817. https://doi.org/10.1111/iwj.14817
2. Armstrong DG, Tan TW, Boulton AJM, and Bus SA. Diabetic foot ulcers: A review. JAMA. 2023;330(1):62-75. doi:10.1001/jama.2023.10578
3. Armstrong DG, Swerdlow MA, Armstrong AA, Conte MS, Padula WV, and Bus SA. Five year mortality and direct costs of care for people with diabetic foot complications are comparable to cancer. J Foot Ankle Res. 2020;13:16. doi: 10.1186/s13047-020-00383-2

About Microbion

Microbion is a clinical-stage pharmaceutical company developing a new class of therapeutic compounds to improve the lives of patients with rare and serious diseases. Microbion's lead drug candidate, pravibismane, is the first product in this new class and has multiple novel modes of action, including potent broad spectrum anti-infective, antibiofilm, and a direct anti-inflammatory effect, offering unique potential to address the unmet needs of chronic and severe health conditions. Topical pravibismane completed Phase 2 development for the treatment of chronic wounds. Local pravibismane is in Phase 2 clinical development for orthopedic infections and inhaled pravibismane is advancing into Phase 1 clinical development for the treatment of chronic lung diseases, including non-tuberculous mycobacteria (NTM) and cystic fibrosis-related lung infections. Pravibismane has received backing from the Cystic Fibrosis Foundation, NIH, US DoD, and CARB-X with over $22 million in non-dilutive grants. The FDA has granted pravibismane Orphan Drug, Fast Track, and Qualified Infectious Disease Product (QIDP) designations.   

For more information visit: www.microbioncorp.com.

Safe Harbor Statement

Certain of the statements made in this press release are forward-looking, such as those, among others, relating to the success of clinical development of pravibismane and preparation for potential commercialization. These statements are subject to risks and uncertainties that could cause actual results and events to differ materially from those anticipated, including, but not limited to, risks and uncertainties related to: our ability to enroll patients in our clinical trials at the pace that we project; the size and growth of the potential markets for pravibismane or any future product candidates and our ability to serve those markets; our ability to obtain and maintain regulatory approval of pravibismane or any future product candidates; and our expectations regarding the potential safety, efficacy or clinical utility of pravibismane or any future product candidates. Actual results or developments may differ materially from those projected or implied in these forward-looking statements. Microbion Corporation disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.

SOURCE Microbion Corporation