The WHO Global Gonococcal Antimicrobial Surveillance Programme (WHO GASP), monitors trends in drug-resistant gonorrhoea. WHO GASP data from 2009 to 2014 find widespread resistance to ciprofloxacin [97% of countries that reported data in that period found drug-resistant strains], increasing resistance to azithromycin [81%], and the emergence of resistance to the current last-resort treatment: the extended-spectrum cephalosporins (ESCs) oral cefixime or injectable ceftriaxone [66%].
Currently, in most countries, ESCs are the only single antibiotic that remain effective for treating gonorrhoea. But resistance to cefixime – and more rarely to ceftriaxone – has now been reported in more than 50 countries. As a result, WHO issued updated global treatment recommendations in 2016 advising doctors to give 2 antibiotics: ceftriaxone and azithromycin.
Development of new drugs
The R&D pipeline for gonorrhoea is relatively empty, with only 3 new candidate drugs in various stages of clinical development: solithromycin, for which a phase III trial has recently been completed; zoliflodacin, which has completed a phase II trial; and gepotidacin, which has also completed a phase II trial.
The development of new antibiotics is not very attractive for commercial pharmaceutical companies. Treatments are taken only for short periods of time (unlike medicines for chronic diseases) and they become less effective as resistance develops, meaning that the supply of new drugs constantly needs to be replenished.