Sanofi’s oral sleeping sickness candidate acoziborole has achieved 95% efficacy in a late-phase clinical trial, delivering a boost to a global push to interrupt transmission of the parasitic disease by 2030.
Patients with late-stage disease have traditionally been hospitalized and given an oral medication three times a day for 10 days and an intravenous therapy twice a day for seven days. The treatment is highly effective, but the need to hospitalize patients for days and administer tens of doses prevents people in some of the remote, unstable areas affected by the disease from receiving treatment. In recent years, fexinidazole has emerged as an all-oral alternative, but it must be taken for 10 days with food.
Acoziborole, an oral benzoxaborole-6-carboxamide co-developed by the Drugs for Neglected Diseases initiative, is designed to simplify the treatment of the disease. In the phase 2/3 clinical trial, details of which were published in The Lancet, 208 people with sleeping sickness received a single 960-mg dose, consisting of three tablets, while fasted.
Eighteen months later, the treatment success rate in the 167 patients with late-stage disease was 95%. The clinical trial defined success as the absence of parasites and the meeting of a white blood cell target, factors that indicated a cure or probable cure.
The study lacked a control arm, but the researchers compared the results to historical data on other drug regimens in a post hoc analysis. In the pivotal fexinidazole trial, the 10-day oral treatment posted a 91% success rate, while the oral-intravenous cocktail that has traditionally been used worked 98% of the time.
On the safety side, 14% of the recipients of acoziborole experienced drug-related treatment-emergent adverse events. All of the events were of mild or moderate severity. Fever and lack of energy were the most common events.
Based on the data, the researchers concluded the molecule “holds promise” for efforts to achieve the World Health Organization’s goal of interrupting transmission of the disease by 2030. Sanofi sees scope to use the drug in a “screen-and-treat” approach, whereby patients are diagnosed using a pinprick blood test and given acoziborole without undergoing parasitological confirmation or hospitalization.
“Even though we have good treatment options now, we still need to send people who test positive with a sleeping sickness rapid test from their village to a confirmatory health center. Acoziborole could potentially become the first treatment that would allow doctors to treat people on the spot, once they receive a positive rapid test in their village,” Mariame Camara, principal investigator of the study, said in a statement.