Summit Announces Publication of Phase 2 Clinical Analyses of Gut Microbiome Health
July 13, 2020 – Summit Therapeutics plc announced the publication of data from the Phase 2 clinical trial of the company’s precision antibiotic, ridinilazole, in development for the treatment of C. difficile infection (‘CDI’) in the American Journal of Physiology – Gastrointestinal and Liver Physiology. The data published in collaboration with researchers at Tufts University and Tufts Medical Center demonstrated that ridinilazole’s microbiome preservation resulted in a gut environment expected to inhibit the growth of C. difficile. In contrast, vancomycin treatment resulted in a gut environment that may more highly favor the growth of C. difficile. The difference in gut environment could explain the approximately 60% relative reduction in recurrence observed in patients treated with ridinilazole over vancomycin in the Phase 2 trial.
“This is the first scientific article ever to show the effect of antibiotics treating CDI on the bile acid composition in the human gut. In addition, CoDIFy is the first clinical study to highlight the differential effects of antibiotics on bile acids, which are known to create environments that can either promote or protect against CDI,” said Dr. Ventzislav Stefanov, Executive Vice President and President of Discuva. “The protective gut environment observed after ridinilazole treatment, compared to vancomycin, provides a strong rationale for the higher sustained clinical response observed in patients taking ridinilazole in the CoDIFy clinical trial.”
The Phase 2 clinical trial enrolled 100 patients, half of whom received ridinilazole and the other half vancomycin. The publication, “Ridinilazole, a narrow spectrum antibiotic for treatment of Clostridioides difficile infection, enhances preservation of microbiota-dependent bile acids,” was authored by X. Qian, K. Yanagi, A. Kane, N. Alden, M. Lei, D. Snydman, R. Vickers, K. Lee and C. Thorpe. In the published data, there was a higher ratio of pro-C. difficile to anti C.-difficile bile acids at the start of treatment for both ridinilazole- and vancomycin-treated patients. This was expected, as patients who get CDI have perturbed microbiomes. However, during treatment, patients treated with vancomycin showed a further decrease in anti-C. difficile bile acids and had stools dominated by pro-C. difficile bile acids. In contrast, this did not occur in ridinilazole-treated patients. By the end of the study period, ridinilazole-treated patients’ bile acid ratios trended 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.
Summit Doses First Patient in Phase 3 Clinical Trials of Precision Antibiotic Ridinilazole for C. Difficile Infection
Trials Aim to Show Superiority of Ridinilazole Over Standard of Care Treatment Vancomycin
Health Economic Outcomes Included to Support Commercialisation
FROM PRESS RELEASE:
Oxford, UK, and Cambridge, MA, US, 13 February 2019 – Summit Therapeutics plc (NASDAQ: SMMT, AIM: SUMM), a leader in new mechanism antibiotic innovation, today announces it has dosed the first patient in the global Phase 3 clinical trials of its precision oral antibiotic, ridinilazole, for C. difficile infection (‘CDI’). The trials aim to show superiority of ridinilazole over the standard of care, vancomycin, in a measure that combines CDI cure and recurrence called sustained clinical response (‘SCR’). Ridinilazole achieved statistical superiority over vancomycin in SCR in a Phase 2 clinical trial.
“Starting our Phase 3 programme is an important milestone for Summit,” commented Mr Glyn Edwards, Chief Executive Officer of Summit. “With positive results, we believe ridinilazole could be positioned as the drug of choice in the front-line treatment of CDI, which potentially provides patients with sustained cures and hospitals with compelling cost savings.”
“Ridinilazole is the trail-blazer in our growing pipeline of innovative product candidates targeting serious infectious diseases,” added Dr David Roblin, President of R&D of Summit. “Our Phase 3 programme exemplifies our broader strategy of demonstrating significant advantages over current standards of care by gathering a carefully considered package of clinical and economic data to address the needs of physicians, regulators, healthcare providers, payors and, above all, patients.”
The Phase 3 clinical programme comprises two global, randomised, double-blind, active-controlled clinical trials called Ri-CoDIFy 1 and Ri-CoDIFy 2. The trials will be run concurrently with each expected to enrol approximately 680 patients at sites in North America, Latin America, Europe, Australia and Asia. Upon confirmation of a positive CDI toxin test, patients will be randomised to receive either ridinilazole (200mg twice a day) or vancomycin (125mg four times a day) for ten days. The primary endpoint of both clinical trials will test for superiority in SCR, defined as cure at the end of treatment and no recurrence of CDI within 30 days post-treatment. Secondary endpoints include cure at the end of treatment and SCR at 60 days and 90 days post-treatment. Additional endpoints will evaluate the impact of ridinilazole and vancomycin on the gut microbiome, which is known to protect against CDI. The Phase 3 clinical trials also include health economic outcome measures, such as readmission rates and length of hospital stay, to help support the commercialisation of ridinilazole, if approved.
Top-line data from the Phase 3 programme are expected to be reported in the second half of 2021.
The clinical and regulatory development of ridinilazole is being funded in part with Federal funds from the US Department of Health and Human Services, Office of the Assistant Secretary for Preparedness and Response, Biomedical Advanced Research and Development Authority (‘BARDA’), under Contract No. HHS0100201700014C. Summit is eligible to receive up to $62 million in funding from BARDA to support the clinical and regulatory development of ridinilazole.
Ridinilazole is an oral small molecule new mechanism antibiotic that is designed to selectively kill C. difficile, thereby preserving patients’ protective gut microbiome and leading to sustained CDI cures. In a Phase 2 proof of concept trial in CDI patients, ridinilazole showed statistical superiority in sustained clinical response (‘SCR’) rates compared to the standard of care, vancomycin. In that trial, SCR was defined as clinical cure at end of treatment and no recurrence of CDI within 30 days of the end of therapy. Ridinilazole was also shown to be highly preserving of the gut microbiome in the Phase 2 proof of concept trial, which was believed to be the reason for the improved clinical outcome for the ridinilazole-treated patients. In addition, ridinilazole preserved the gut microbiome to a greater extent than the marketed narrow-spectrum antibiotic fidaxomicin in an exploratory Phase 2 clinical trial. Ridinilazole has received Qualified Infectious Disease Product (‘QIDP’) designation and has been granted Fast Track designation by the US Food and Drug Administration. The QIDP incentives are provided through the US GAIN Act and include a potential extension of marketing exclusivity for an additional five years upon FDA approval.
About Summit Therapeutics
Summit Therapeutics is a leader in antibiotic innovation. Our new mechanism antibiotics are designed to become the new standards of care for the benefit of patients and create value for payors and healthcare providers. We are currently developing new mechanism antibiotics for infections caused by C. difficile,N. gonorrhoeae and ESKAPE pathogens and are using our proprietary Discuva Platform to expand our pipeline.
Summit Therapeutics — the drug discovery and development company advancing therapies for Duchenne muscular dystrophy and Clostridium difficile infection (‘CDI’), announces that it has entered into an exclusive license and commercialization agreement granting Eurofarma Laboratórios SA (‘Eurofarma’) rights in Latin America (the ‘Licensed Territory’) to Summit’s precision antibiotic ridinilazole in development for the treatment of CDI.
Summit retains commercialization rights in all other countries.
ridinilazole is a targeted antibiotic that has the potential as a frontline therapy to treat initial infection and preserve patients’ microbiomes to reduce the rate of recurrent CDI. In a Phase 2 proof of concept trial in CDI patients, ridinilazole demonstrated statistical superiority in sustained clinical response (‘SCR’) rates compared to the standard of care, vancomycin.
ridinilazole is expected to enter Phase 3 clinical trials in the first half of 2018.
“Eurofarma’s established infrastructure and expertise in Latin America are ideally placed to commercialise our novel antibiotic, ridinilazole,”commented Glyn Edwards, Chief Executive Officer of Summit. “This agreement, combined with the recent contract award of up to $62 million from the US Government agency BARDA, will further support the Phase 3 clinical programme and regulatory development of ridinilazole. These partnerships endorse the potential of ridinilazole in the treatment of CDI, and move us a step closer to bringing this antibiotic to patients.”
Eurofarma is a multinational pharmaceutical company with headquarters in Brazil and operations in over 20 countries in South and Central America, the Caribbean and Africa. Eurofarma has a broad portfolio of products across multiple therapeutic areas including a focus in infectious diseases where it markets a number of antibiotics.
“CDI is a serious global healthcare threat including in Latin America,” added Martha Penna, P&D Vice-president of Eurofarma. “Through our interest in bringing innovative products to the region, we were impressed by the efficacy data from the ridinilazole Phase 2 programme and the differentiated profile of the drug. We believe it has the potential to address a major unmet need in CDI, and we look forward to working with Summit to bring ridinilazole to market for the benefit of patients.”
Under the terms of the licence and commercialisation agreement, Summit will receive an upfront payment of $2.5 million, and is entitled to receive a further $3.75 million in development milestones upon the achievement of staged patient enrolment targets in the planned Phase 3 clinical trials of ridinilazole. Summit is eligible to receive up to an additional $21.4 million through other development milestones, commercial milestones, and one-time sales milestones based on cumulative net sales up to $100 million in the Licensed Territory. Further, the agreement provides for product supply transfer payments expected to provide a return equivalent to a high single digit to low double-digit percentage of net sales. For each incremental $100 million in cumulative net sales achieved, Summit is entitled to a further milestone payment which, when combined with the aforementioned product supply transfer payments, is expected to provide a return equivalent to a mid- to high-teens percentage of net sales.
Eurofarma will be responsible for obtaining regulatory approval for ridinilazole in the Licensed Territory. Summit retains full responsibility for the clinical development of ridinilazole in all countries, and is responsible for obtaining regulatory approvals outside of the Eurofarma licensed territories.
A Form 6-K will be filed with the US Securities and Exchange Commission (‘SEC’) that contains additional information about the terms of the licence and commercialisation agreement with Eurofarma.
A copy of this Form 6-K will be available to download either from the Investors section of the Company website at www.summitplc.com or from the SEC website at www.sec.gov.
This announcement contains inside information for the purposes of Article 7 of EU Regulation 596/2014 (MAR).
Ridinilazole is a small molecule precision antibiotic that Summit is developing for the treatment of CDI. In preclinical efficacy studies, ridinilazole exhibited a targeted spectrum of activity that combined a potent bactericidal effect against all clinical isolates of C. difficile tested with minimal impact on other bacteria that are typically found in the gut microbiome. In a Phase 2 proof of concept trial in CDI patients, ridinilazole showed statistical superiority in sustained clinical response (‘SCR’) rates compared to the standard of care, vancomycin. In that trial, SCR was defined as clinical cure at end of treatment and no recurrence of CDI within 30 days of the end of therapy. Ridinilazole was also shown to be highly preserving of the gut microbiome in the Phase 2 proof of concept trial, which was believed to be the reason for the improved clinical outcome for the ridinilazole-treated patients. In addition, ridinilazole preserved the gut microbiome to a greater extent than the marketed narrow-spectrum antibiotic fidaxomicin in an exploratory Phase 2 clinical trial. Ridinilazole, an orally administered small molecule, has received Qualified Infectious Disease Product (‘QIDP’) designation and has been granted Fast Track designation by the US Food and Drug Administration. The QIDP incentives are provided through the US GAIN Act and include an extension of marketing exclusivity for an additional five years upon FDA approval.
About Summit Therapeutics
Summit is a biopharmaceutical company focused on the discovery, development and commercialisation of novel medicines for indications for which there are no existing or only inadequate therapies. Summit is conducting clinical programmes focused on the genetic disease Duchenne muscular dystrophy and the infectious disease C. difficile infection. Further information is available at www.summitplc.com and Summit can be followed on Twitter (@summitplc).
About the Eurofarma Group
As the first 100% Brazilian-owned multinational pharmaceutical company, Eurofarma has been in existence for 45 years, has 6,500 employees, and has operations in 20 Latin American countries. With 12 manufacturing plants in the region, the company has more than 280 products in its portfolio. In 2016, it produced more than 290 million units and reached revenues of R$3.3 billion, 15.7% higher than the previous year. The Group invests approximately 5.5% of its net sales in Research & Development and maintains a pipeline of more than 175 projects.
About Eurofarma Brazil
Considered one of the best companies to work for, Eurofarma Brazil is also considered the most sustainable pharmaceutical company in the country based on an analysis by the Exame Sustainability Guide. With operations in all main pharmaceutical segments including Medical Prescriptions, Generics, Hospital, Oncology, Veterinary, and Bids and Services to Third Parties, Eurofarma has the largest medical advertising salesforce in Brazil with more than 2,000 representatives that together perform 450,000 medical contacts per month. The company has the 4th largest pharmacy system in the country and has a portfolio of medicines that is the 2nd largest by prescription volume.
SUMMIT ANNOUNCES POSITIVE TOP-LINE DATA FROM AN EXPLORATORY PHASE 2 CLINICAL TRIAL SUPPORTING RIDINILAZOLE AS A HIGHLY SELECTIVE ANTIBIOTIC FOR THE TREATMENT OF CDI
Ridinilazole treatment more preserving of gut microbiome than fidaxomicin
* Listen In on September 26th 10aPT/1pET www.cdiffradio.com live broadcast with our guests from Summit Therapeutics.
Oxford, UK, 5 September 2017 – Summit Therapeutics plc (NASDAQ: SMMT, AIM: SUMM), the drug discovery and development company advancing therapies for Duchenne muscular dystrophy and Clostridium difficile infection (‘CDI’), today announces positive top-line data from an exploratory Phase 2 clinical trial that support ridinilazole as a highly selective and potent antibiotic product candidate for the treatment of CDI. In the Phase 2 clinical trial, ridinilazole preserved the gut microbiome of CDI patients to a greater extent than the marketed narrow-spectrum antibiotic, fidaxomicin. During the trial’s ten-day treatment period, ridinilazole treatment had markedly less impact on the gut microbiome of trial patients by measures of overall diversity and changes in key bacterial families, when compared to those trial patients dosed with fidaxomicin.
In the trial, ridinilazole and fidaxomicin both reduced the abundance of C. difficile. However, fidaxomicin-treated patients had reduced abundancy of other bacterial families associated with microbiome health. For a number of these bacterial families, the difference between the two treatments was statistically significant. Another measure of microbiome health is alpha diversity as measured by the Simpson’s Diversity Index. There was a greater reduction in alpha-diversity during fidaxomicin treatment compared with ridinilazole-treated patients. These measures were a key secondary endpoint of the clinical trial and provide additional evidence of ridinilazole’s precision in killing C. difficile while preserving the gut microbiome. The primary endpoint of the trial was safety, as measured by the number of treatment emergent adverse events and serious adverse events. During the trial, no new or unexpected safety signals were identified and ridinilazole was well-tolerated.
“We increasingly recognise the importance of a healthy and diverse gut microbiome for protection against recurrent CDI, which is a major challenge in the management of the disease. These latest clinical findings show ridinilazole better preserved the microbiome of CDI patients than fidaxomicin, the narrowest spectrum antibiotic currently available for CDI,”commented Professor Mark Wilcox, Consultant Microbiologist & Head of Microbiology Research & Development at the Leeds Teaching Hospitals NHS Trust, Professor of Medical Microbiology at the University of Leeds, and Public Health England’s Lead on C. difficile in England. “Further, these microbiome data are very supportive of ridinilazole’s profile as a highly selective antibiotic with the potential to achieve a meaningful improvement in clinical outcomes for CDI patients.”
The exploratory open-label Phase 2 clinical trial enrolled 27 patients aged between 18 and 90 years at trial sites in the US, the UK and the Czech Republic. Patients were randomly assigned to receive either ridinilazole (200mg, twice a day) or fidaxomicin (200mg, twice a day) for ten days. The trial population was unbalanced with more patients randomised to ridinilazole at higher risk of poorer clinical outcomes as measured by ATLAS score, and also with predisposing factors for recurrent CDI.
A secondary endpoint of sustained clinical response (‘SCR’), defined as clinical cure at the end of treatment and no recurrence of CDI within the next 30 days, was achieved in seven of 14 ridinilazole treated patients and six of 13 fidaxomicin treated patients. The trial was not designed for efficacy comparisons due to the small number of patients.
Dr David Roblin, Chief Medical and Operating Officer of Summitadded, “Ridinilazole is a precision antibiotic that is designed to selectively target C. difficile while being highly preserving of the gut microbiome that plays a crucial role in naturally protecting against recurrent CDI. Ridinilazole has now provided evidence of its high selectivity in two complementary clinical trials. The data from our earlier Phase 2 trial showed a greater microbiome preservation of ridinilazole-treated patients compared with the current standard of care, vancomycin, which led to achieving statistical superiority in sustained clinical response. We believe ridinilazole has the potential to become a front-line therapy for CDI and look forward to initiating Phase 3 clinical trials in the first half of 2018.”
More detailed findings from this trial are expected to be presented at an upcoming international infectious disease conference. The results build on positive data from a Phase 2 proof of concept trial of ridinilazole that were published in The Lancet Infectious Diseases in April 2017. Ridinilazole is currently being prepared for Phase 3 clinical trials that are planned to commence in the first half of 2018.
Clostridium difficile infection is the most common health-care-associated infection in the USA. We assessed the safety and efficacy of ridinilazole versus vancomycin for treatment of C difficile infection.
We did a phase 2, randomized, double-blind, active-controlled, non-inferiority study. Participants with signs and symptoms of C difficile infection and a positive diagnostic test result were recruited from 33 centres in the USA and Canada and randomly assigned (1:1) to receive oral ridinilazole (200 mg every 12 h) or oral vancomycin (125 mg every 6 h) for 10 days. The primary endpoint was achievement of a sustained clinical response, defined as clinical cure at the end of treatment and no recurrence within 30 days, which was used to establish non-inferiority (15% margin) of ridinilazole versus vancomycin. The primary efficacy analysis was done on a modified intention-to-treat population comprising all individuals with C difficile infection confirmed by the presence of free toxin in stool who were randomly assigned to receive one or more doses of the study drug. The study is registered with ClinicalTrials.gov, number NCT02092935.
Between June 26, 2014, and August 31, 2015, 100 patients were recruited; 50 were randomly assigned to receive ridinilazole and 50 to vancomycin. 16 patients did not complete the study, and 11 discontinued treatment early. The primary efficacy analysis included 69 patients (n=36 in the ridinilazole group; n=33 in the vancomycin group). 24 of 36 (66·7%) patients in the ridinilazole group versus 14 of 33 (42·4%) of those in the vancomycin group had a sustained clinical response (treatment difference 21·1%, 90% CI 3·1–39·1, p=0·0004), establishing the non-inferiority of ridinilazole and also showing statistical superiority at the 10% level. Ridinilazole was well tolerated, with an adverse event profile similar to that of vancomycin: 82% (41 of 50) of participants reported adverse events in the ridinilazole group and 80% (40 of 50) in the vancomycin group. There were no adverse events related to ridinilazole that led to discontinuation.
Ridinilazole is a targeted-spectrum antimicrobial that shows potential in treatment of initial C difficile infection and in providing sustained benefit through reduction in disease recurrence. Further clinical development is warranted.
Wellcome Trust and Summit Therapeutics.
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