Bubonic plague
Maritampona village, the location of one of the trial’s participating health centres
IMASOY – Bubonic Plague
An open-label, randomised, non-inferiority trial of the efficacy and safety of ciprofloxacin versus streptomycin + ciprofloxacin in the treatment of bubonic plague.
The IMASOY trial aims to test the hypothesis that ciprofloxacin monotherapy is non-inferior to streptomycin followed by ciprofloxacin in the treatment of bubonic plague.
The trial is being conducted at 50 peripheral health centres (Centres de Santé de Base) in Madagascar in conjunction with Institut Pasteur de Madagascar and Centre Hospitalier Universitaire Joseph Raseta Befelatanana.
IMASOY trial in Tsiroanomandidy. Josephine Bourner, ISARIC
Rationale
Current treatment regimens for bubonic plague rely heavily on aminoglycosides, which are costly, cause high toxicity, require injections and are in low global supply.
Ciprofloxacin has been shown to have high therapeutic efficacy in the treatment of plague, equivalent or superior to current treatment regimens. It also can be administered orally, having good oral bioavailability, an established safety record, and is cheaper and more readily available in LMICs (where over 98% of the global disease burden lies).
The trial estimates that 600 patients will need to be randomised in order to obtain a sample size of 190 patients with confirmed or probable bubonic plague. Patients will be randomised to receive either:
- Streptomycin followed by ciprofloxacin (the current first-line treatment in Madagascar)
- Ciprofloxacin alone (the current third-line treatment in Madagascar)
The primary endpoint of the trial will assess the proportion of patients with bubonic plague who have a therapeutic response to treatment.
Current status
The IMASOY trial has now reached its minimum target sample size. We will continue enrolling participants until the end of March 2024 to mitigate the risk of the non-inferiority design being under-powered and to increase the precision of the results, which we aim to publish towards the end of 2024.
For further information about IMASOY please contact josephine.bourner@ndm.ox.ac.uk
Once a suspected case of plague has been identified, assessed for eligibility and included in the trial, they will be randomised to one of two possible treatments: streptomycin + ciprofloxacin OR ciprofloxacin alone. Treatment in both arms will last for 10 consecutive days. Included patients will then be followed up on days 11 and 21. For those who receive a positive result for plague at day 21, they will attend another follow-up visit at month 3 and for those still testing positive for plague at month 3, they will attend a final visit at month 12.
Publication library
The IMASOY trial team preparing to visit a patient in Tsiroanomandidy. Josephine Bourner, ISARIC
One of the health centres participating in the trial in Ambositra. Josephine Bourner, ISARIC