Efficacy and safety of ridinilazole compared with vancomycin for the treatment of Clostridium difficile infection: a phase 2, randomised, double-blind, active-controlled, non-inferiority study

Richard J Vickers, Glenn S Tillotson, Richard Nathan, Sabine Hazan, John Pullman, Christopher Lucasti, Kenneth Deck, Bruce Yacyshyn, Benedict Maliakkal, Yves Pesant, Bina Tejura, David Roblin, Dale N Gerding, Mark H Wilcox, CoDIFy study group, Amit Bhan, Wayne Campbell, Teena Chopra, Kenneth Deck, Yoav Golan, Ian Gordon, Ravi Kamepalli, Sahil Khanna, Christine Lee, Christopher Lucasti, Benedict Maliakkal, Irene Minang, Kathleen Mullane, Richard Nathan, Matthew Oughton, Yves Pesant, John Phillips, John Pullman, Paul Riska, Christian Schrock, Jonathan Siegel, Alon Steinberg, David Talan, Stephen Tamang, Michael Tan, Karl Weiss, Chia Wang, Bruce Yacyshyn, Jo-Anne Young, Jonathan Zenilman, Richard J Vickers, Glenn S Tillotson, Richard Nathan, Sabine Hazan, John Pullman, Christopher Lucasti, Kenneth Deck, Bruce Yacyshyn, Benedict Maliakkal, Yves Pesant, Bina Tejura, David Roblin, Dale N Gerding, Mark H Wilcox, CoDIFy study group, Amit Bhan, Wayne Campbell, Teena Chopra, Kenneth Deck, Yoav Golan, Ian Gordon, Ravi Kamepalli, Sahil Khanna, Christine Lee, Christopher Lucasti, Benedict Maliakkal, Irene Minang, Kathleen Mullane, Richard Nathan, Matthew Oughton, Yves Pesant, John Phillips, John Pullman, Paul Riska, Christian Schrock, Jonathan Siegel, Alon Steinberg, David Talan, Stephen Tamang, Michael Tan, Karl Weiss, Chia Wang, Bruce Yacyshyn, Jo-Anne Young, Jonathan Zenilman

Abstract

Background: 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.

Methods: We did a phase 2, randomised, 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.

Findings: 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.

Interpretation: 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.

Funding: Wellcome Trust and Summit Therapeutics.

Copyright © 2017 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.

Figures

Figure 1
Figure 1
Trial profile ITT=intention-to-treat.
Figure 2
Figure 2
Efficacy analysis in the modified intention-to-treat population SCR=sustained clinical response.
Figure 3
Figure 3
Subgroup analysis of sustained clinical response in the modified intention-to-treat population

References

    1. Magill SS, Edwards JR, Bamberg W. Multistate point-prevalence survey of health care-associated infections. N Engl J Med. 2014;370:1198–1208.
    1. Lessa FC, Mu Y, Bamberg WM. Burden of Clostridium difficile infection in the United States. N Engl J Med. 2015;372:825–834.
    1. Davies KA, Longshaw CM, Davis GL. Underdiagnosis of Clostridium difficile across Europe: the European, multicentre, prospective, biannual, point-prevalence study of Clostridium difficile infection in hospitalised patients with diarrhoea (EUCLID) Lancet Infect Dis. 2014;14:1208–1219.
    1. Bauer MP, Notermans DW, van Benthem BH, for the ECDIS Study Group Clostridium difficile infection in Europe: a hospital-based survey. Lancet. 2011;377:63–73.
    1. Magee G, Strauss ME, Thomas SM, Brown H, Baumer D, Broderick KC. Impact of Clostridium difficile-associated diarrhea on acute care length of stay, hospital costs, and readmission: a multicenter retrospective study of inpatients, 2009–2011. Am J Infect Control. 2015;43:1148–1153.
    1. Wiegand PN, Nathwani D, Wilcox MH, Stephens J, Shelbaya A, Haider S. Clinical and economic burden of Clostridium difficile infection in Europe: a systematic review of healthcare-facility-acquired infection. J Hosp Infect. 2012;81:1–14.
    1. Louie TJ, Miller MA, Mullane KM, for the OPT-80-003 Clinical Study Group Fidaxomicin versus vancomycin for Clostridium difficile infection. N Engl J Med. 2011;364:422–431.
    1. Cornely OA, Crook DW, Esposito R, for the OPT-80-004 Clinical Study Group Fidaxomicin versus vancomycin for infection with Clostridium difficile in Europe, Canada, and the USA: a double-blind, non-inferiority, randomised controlled trial. Lancet Infect Dis. 2012;12:281–289.
    1. Kelly CP. Can we identify patients at high risk of recurrent Clostridium difficile infection? Clin Microbiol Infect. 2012;18(suppl 6):21–27.
    1. Ghantoji SS, Sail K, Lairson DR, DuPont HL, Garey KW. Economic healthcare costs of Clostridium difficile infection: a systematic review. J Hosp Infect. 2010;74:309–318.
    1. Surawicz CM, Brandt LJ, Binion DG. Guidelines for diagnosis, treatment, and prevention of Clostridium difficile infections. Am J Gastroenterol. 2013;108:478–498.
    1. Debast SB, Bauer MP, Kuijper EJ. European Society of Clinical Microbiology and Infectious Diseases: update of the treatment guidance document for Clostridium difficile infection. Clin Microbiol Infect. 2014;20(suppl 2):1–26.
    1. Johnson S, Louie TJ, Gerding DN, on behalf of the Polymer Alternative for CDI Treatment (PACT) investigators Vancomycin, metronidazole, or tolevamer for Clostridium difficile infection: results from two multinational, randomized, controlled trials. Clin Infect Dis. 2014;59:345–354.
    1. Peterfreund GL, Vandivier LE, Sinha R. Succession in the gut microbiome following antibiotic and antibody therapies for Clostridium difficile. PLoS One. 2012;7:e46966.
    1. Goldstein EJ, Citron DM, Tyrrell KL, Merriam CV. Comparative in vitro activities of SMT19969, a new antimicrobial agent, against Clostridium difficile and 350 Gram-positive and Gram-negative aerobic and anaerobic intestinal flora isolates. Antimicrob Agents Chemother. 2013;57:4872–4876.
    1. Goldstein EJ, Citron DM, Tyrrell KL. Comparative in vitro activities of SMT19969, a new antimicrobial agent, against 162 strains from 35 less frequently recovered intestinal Clostridium species: implications for Clostridium difficile recurrence. Antimicrob Agents Chemother. 2014;58:1187–1191.
    1. Corbett D, Wise A, Birchall S. In vitro susceptibility of Clostridium difficile to SMT19969 and comparators, as well as the killing kinetics and post-antibiotic effects of SMT19969 and comparators against C. difficile. J Antimicrob Chemother. 2015;70:1751–1756.
    1. Freeman J, Vernon J, Vickers R, Wilcox MH. Susceptibility of Clostridium difficile isolates of varying antimicrobial resistance phenotypes to SMT19969 and 11 comparators. Antimicrob Agents Chemother. 2016;60:689–692.
    1. Baines SD, Crowther GS, Freeman J, Todhunter S, Vickers R, Wilcox MH. SMT19969 as a treatment for Clostridium difficile infection: an assessment of antimicrobial activity using conventional susceptibility testing and an in vitro gut model. J Antimicrob Chemother. 2015;70:182–189.
    1. Sattar A, Thommes P, Payne L, Warn P, Vickers RJ. SMT19969 for Clostridium difficile infection (CDI): in vivo efficacy compared with fidaxomicin and vancomycin in the hamster model of CDI. J Antimicrob Chemother. 2015;70:1757–1762.
    1. Vickers R, Robinson N, Best E, Echols R, Tillotson G, Wilcox M. A randomised phase 1 study to investigate safety, pharmacokinetics and impact on gut microbiota following single and multiple oral doses in healthy male subjects of SMT19969, a novel agent for Clostridium difficile infections. BMC Infect Dis. 2015;15:91.
    1. Louie T, Nord CE, Talbot GH. Multicenter, double-blind, randomized, phase 2 study evaluating the novel antibiotic cadazolid in patients with Clostridium difficile infection. Antimicrob Agents Chemother. 2015;59:6266–6273.
    1. Planche TD, Davies KA, Coen PG. Differences in outcome according to Clostridium difficile testing method: a prospective multicentre diagnostic validation study of C difficile infection. Lancet Infect Dis. 2013;13:936–945.
    1. Longtin Y, Trottier S, Brochu G. Impact of the type of diagnostic assay on Clostridium difficile infection and complication rates in a mandatory reporting program. Clin Infect Dis. 2013;56:67–73.
    1. Polage CR, Gyorke CE, Kennedy MA. Overdiagnosis of Clostridium difficile infection in the molecular test era. JAMA Int Med. 2015;175:1792–1801.
    1. UK Department of Health Updated guidance on the diagnosis and reporting of Clostridium difficile. March 6, 2012. (accessed March 15, 2017).
    1. Crobach MJ, Planche T, Eckert C. European Society of Clinical Microbiology and Infectious Diseases: update of the diagnostic guidance document for Clostridium difficile infection. Clin Microbiol Infect. 2016;22(suppl 4):S63–S81.
    1. Miettinen O, Nurminen M. Comparative analysis of two rates. Stat Med. 1985;4:213–226.
    1. Lessa FC, Gould CV, McDonald LC. Current status of Clostridium difficile infection epidemiology. Clin Infect Dis. 2012;55(suppl 2):S65–S70.
    1. Louie TJ, Miller MA, Crook DW. Effect of age on treatment outcomes in Clostridium difficile infection. J Am Geriatr Soc. 2013;61:222–230.
    1. Johnson S. Recurrent Clostridium difficile infection: a review of risk factors, treatments, and outcomes. J Infect. 2009;58:403–410.
    1. Buffie CG, Pamer G. Microbiota-mediated colonization resistance against intestinal pathogens. Nat Rev Immunol. 2013;13:790–801.
    1. Chang J, Kane A, Snydman DR, et al. Ridinilazole preserves major components of the intestinal microbiota during treatment of Clostridium difficile infection. American Society for Microbiology; Boston, MA; June 16–20, 2016. Abstr LB-116.
    1. Johnson S, Gerding DN, Louie TJ, Ruiz NM, Gorbach SL. Sustained clinical response as an endpoint in treatment trials of Clostridium difficile-associated diarrhea. Antimicrob Agents Chemother. 2012;56:4043–4045.

Source: PubMed

3
Tilaa