Tag Archives: Are there C. difficile clinical trials?

Clostridioides diffiicle Thrives In an Inflammed Environement ….Research Study From North Carolina State University

Clostridioides difficile thrives in an inflamed environment by generating toxins that support prolonged infection, according to a study from North Carolina State University.

The study, published in Nature Communications, showed how C. diff produces toxins that cause inflammation, eliminating competing bacteria and releasing peptides and amino acids that support the growth of C. diff.

C. diff thrives when other microbes in the gut are absent – which is why it is more prevalent following antibiotic therapy,” corresponding author Casey Theriot, Ph.D., associate professor of infectious disease at North Carolina State University, said. “But when colonizing the gut,
C. diff. also produces two large toxins, TcdA and TcdB, which cause inflammation. We wanted to know if these inflammation-causing toxins actually give C. diff a survival benefit – whether the pathogen can exploit an inflamed environment in order to thrive.”

Investigators examined two variants of C. diff in vitro and in an antibiotic-treated mouse model. The variants included a wild type C. diff that produces toxins and a genetically modified variant that does not. They found that the wild type C. diff, associated with toxin production, generated more inflammation and tissue damage than the mutant.

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Investigators also found changes in the expression of metabolic genes, with C. diff in the inflamed environment expressing more genes related to carbohydrate and amino acid metabolism that sustains growth.

C. diff’s toxins damage the cells that line the gut,” Theriot said. “These cells contain collagen, which is made up of amino acids and peptides. When collagen is degraded by toxins,
C. diff responds by turning on expression of genes that can use these amino acids for growth.”

Inflammation provided a second benefit to C. diff by creating an inhospitable environment for other bacteria that compete for nutrients. Bacteroidaceae were present in control groups that weren’t infected with toxin-producing C. diff, which was consistent with previous studies that found negative associations between C. diff and Bacteroidaceae.

“I always found it interesting that C. diff causes such intense inflammation,” first author Josh Fletcher, Ph.D., a former postdoctoral researcher at North Carolina State University, said. “Our research shows that this inflammation may contribute to the persistence of C. diff in the gut environment, prolonging infection.”

C. diff is the most significant cause of hospital-acquired diarrhea, causing more than 223,900 infections and 12,800 deaths in the US in 2017, according to a recent report.

The disease has two phases, a spore phase, and vegetative phase. Toxins are released during the vegetative phase, causing diarrhea and other symptoms. But the pathogen is often transmitted during the spore phase, during which it is hardy and isn’t susceptible to gastric acids and alcohol-based hand sanitizer, experts explained during a recent discussion of the disease.

Risks for infection include exposure to C. diff spores and antibiotic use. An investigational drug to prevent the disruption of the gut microbiota by antibiotics is among the most recent developments in the fight against a C diff. infection.

 

Summit Therapeutics Shares New Data – Phase 2 Clinical Trial of ridinilazole for C. difficile infection (CDI)

Summit Therapeutics Reports New Data from Phase 2 Clinical Trial Connecting Ridinilazole’s Microbiome Preservation to Improved Clinical Outcomes for Patients with C. difficile Infection

October 2019

Summit Therapeutics announced the presentation of new data that explain the link between two key findings in the Company’s Phase 2 clinical trial of ridinilazole for C. difficile infection (‘CDI’):

  • Ridinilazole demonstrated superior efficacy compared to vancomycin, driven by a 60% lower recurrence rate.
  • Ridinilazole preserved the diversity of the gut microbiome.

Researchers at Tufts University, collaborating with Summit, showed that these findings are connected mechanistically by bile acids, part of the ‘metabolome’ of active chemicals made or modified by gut bacteria. Bile acids exist in different forms that can either favour or block the regrowth of C. difficile after treatment. Vancomycin kills bacteria that turn pro-C. difficile bile acids into anti-C. difficile bile acids – leaving an adverse ratio of pro- and anti-growth chemicals that favours the regrowth of C. difficile and the recurrence of C. difficile infection. By contrast, ridinilazole leaves these bacteria unharmed, allowing them to keep converting pro-C. difficile bile acids into anti-C. difficile bile acids, maintaining a positive chemical balance that prevents C. difficile recurrence.

“The damaging effect of broad-spectrum antibiotics in the treatment of CDI is far-reaching from the make-up and function of the gut microbiome through the poor clinical outcomes seen in one third of patients, driven by a high rate of disease recurrence,” said Dr David Roblin, President of R&D of Summit. “Ridinilazole has the potential to be a targeted CDI treatment that could result in significantly better patient outcomes for the over half million US patients per year who have an episode of CDI. These latest data help to put the science behind the function of a healthy microbiome into context and highlight its importance in sustaining CDI cures.”

The Phase 2 clinical trial enrolled 100 patients, half of whom received ridinilazole and the other half vancomycin. For both groups, there was a higher ratio of pro-C. difficile to anti C.-difficile bile acids at the start of treatment. This was expected, as patients who get CDI have perturbed microbiomes. However, during treatment, the proportion of anti-C. difficile bile acids increased in patients treated with ridinilazole, whereas patients treated with vancomycin initially showed decreases in anti-C. difficile bile acids and had stools dominated by pro-C. difficile bile acids. By the end of treatment, ridinilazole-treated patients’ bile acid ratios returned towards a healthy, non-CDI state. These results support the data from the Phase 2 clinical trial, in which patients receiving ridinilazole showed a statistically significant improvement in sustained clinical responses.

Copies of the two poster presentations are available in the Publications section of Summit’s website, www.summitplc.com.

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C Diff Foundation Recognizes Rebiotix CEO Lee Jones with 2019 ‘Above and Beyond’ Award


C Diff Foundation Board presented Rebiotix CEO Lee Jones for Advocacy, Innovation in
C. difficile infection treatment

 

(NEW PORT RICHEY, Fla.) — The C. Diff Foundation Board of Directors announced that the 2019 “Above and Beyond” Award was presented to Rebiotix CEO Lee Jones in Roseville, Minnesota. The award, given to one recipient annually, is given to a person or organization that show extraordinary dedication to C. diff. patient safety, advocacy, and overall drive to improve the lives of those impacted by the infection.

“We are very proud to recognize Ms. Jones with our “Above and Beyond” award,” said C. Diff Foundation Founder and President, Nancy Caralla. “Lee’s dedication to the entire C.diff. community of patients, family members, and physicians hasn’t wavered since the founding of Rebiotix in 2011. She is a true example of what can happen when focusing on patient well-being drives new approaches to healthcare.”

The award was presented by the Foundation’s Vice President, Scott Battles at the Rebiotix office.

 

 

 

 

 

 

“It’s an honor to receive this award from the C. Diff Foundation,” said Ms. Jones. “The purpose of starting Rebiotix was to bring the power of the microbiome to the clinic in a scientifically sound, quality-controlled way to help patients. We stand with the Foundation in believing that patient well-being should be at the core of all that we do, from clinical trials to exploring new scientific landscapes within the microbiome space.”

About Rebiotix Inc.:

Rebiotix Inc., part of the Ferring Pharmaceuticals Group, is a late-stage clinical microbiome company focused on harnessing the power of the human microbiome to revolutionize the treatment of debilitating diseases. Rebiotix possesses a deep and diverse clinical pipeline, with its lead drug candidate, RBX2660, in Phase 3 clinical development for the prevention of recurrent Clostridium difficile (C. diff) infection. RBX2660 has been granted Fast Track, Orphan and Breakthrough Therapy designation from the FDA for its potential to prevent recurrent C. diff infection.

Rebiotix’s clinical pipeline also features RBX7455, a lyophilized, room temperature stable oral capsule formulation. Rebiotix is also targeting several other disease states with drug products built on its pioneering Microbiota Restoration Therapy(tm) platform. For more information on Rebiotix and its pipeline of human microbiome-directed therapies, visit https://www.rebiotix.com/

 

Da Volterra Shared Results From Phase I Clinical Trial of DAV132 to Prevent Gut Microbiome Disruption Caused by Antibiotics and Prevent C. diff. Infections

DAV132 is a first-in-class product to protect the microbiome during antibiotic treatments and prevent Clostridium difficile infections.

French biotech Da Volterra is developing products to fight the rapidly rising rates of antibiotic resistance. During a Phase I study, the company’s medical device, DAV132, was used with the antibiotic, moxifloxacin, and successfully protected the intestinal microbiota from antibiotic residues. Overall, the product managed to reduce exposure of the microbiota to the antibiotic by 99% and maintain 97.8% of the microbiome’s genetic richness without affecting the drugs therapeutic efficacy.

In a randomized, controlled clinical trial performed in 44 healthy human volunteers, DAV132 was used in association with moxifloxacin, a widely used fluoroquinolone antibiotic. It was demonstrated that DAV132 is able to effectively capture residual antibiotics in the colon and reduce their concentration to very low levels. DAV132 reduced exposure of the intestinal microbiota to moxifloxacin by 99%. Meanwhile the plasma concentration of the antibiotic was essentially unaffected by the co-administration DAV132, meaning that its therapeutic efficacy will be maintained.

The ability of DAV132 to protect the intestinal microbiome was explored by identifying changes in bacterial gene richness as well as a detailed statistical analysis of the evolution of bacterial species throughout the study. In volunteers who received moxifloxacin alone, gene richness was drastically diminished to 54.6% of baseline after antibiotic treatment and failed to return to baseline even one month after treatment; 39% of bacterial species identified in the intestinal microbiota were affected. The co-administration of DAV132 with moxifloxacin largely protected the intestinal microbiome from disruption (97.8% of baseline for bacterial gene richness, and 93% of bacterial species protected).

The primary endpoints for the study were fully achieved and DAV132 showed an excellent tolerability profile.

Annie Ducher MD, Chief Medical Officer of Da Volterra, declared: “This clinical study is indicative of the potential of DAV132 to become one of the first preventative solutions to protect the intestinal microbiome and further avoid the detrimental consequences of antibiotic treatments, such as Clostridium difficile infections, for patients. We look forward to advancing the development of DAV132 in a pivotal patient study in 2018.”

Jean de Gunzburg PhD, Chief Scientific Officer of Da Volterra, added: “This study constitutes the first scientific demonstration of the protection of the intestinal microbiome from dysbiosis caused by a fluoroquinolone antibiotic treatment; our data suggests that this effect should be extendable to many different antibiotics from several therapeutic classes. The metagenomics analysis is outstanding and thoroughly convincing that DAV132 is highly effective at protecting the commensal bacteria in the intestines.”

The results are available under the reference: Gunzburg et al. Protection of the human gut microbiome from antibiotics. The Journal of Infectious Diseases, jix604, https://doi.org/10.1093/infdis/jix604.

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About DAV132:
With a novel and unique mechanism of action, DAV132 is a product candidate aiming to protect the intestinal microbiome from the side effects of antibiotics, hence preventing the onset of C. difficile infections. DAV132 is an adsorbent with a proprietary coating with colon targeted delivery. DAV132 has been tested in four Phase 1 clinical studies with no adverse safety events. DAV132 is currently entering a Phase 2 clinical trial.

About Da Volterra:
Da Volterra is a biopharmaceutical company based in France that develops new strategies aimed at protecting the intestinal microbiome from the deleterious effects of antibiotics, and preventing multi-resistant and life-threatening infections. Da Volterra’s innovative approaches promise a substantial medical progress to combat deadly pathogens. http://www.davolterra.com

(January 2018)

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