Since the novel coronavirus outbreak was first reported in Wuhan, China, on December 31, and as the virus continues to spread internationally, a significant number of clinical trials have initiated, examining potential treatments and vaccines against the virus.
The International Clinical Trials Registry Platform of the World Health Organization (WHO) counts a total of 263 clinical trials related to the novel virus registered from January 23 until February 24.
During a press conference in Beijing last week, the WHO assistant director-general, Bruce Aylward, stated that out of the ongoing clinical trials, the one examining Gilead’s antiviral drug remdesivir shows the most potential.
“There is only one drug right now that we think may have real efficacy and that’s remdesivir,” Aylward said, referring to the investigated candidate. Subsequently, Gilead’s shares rose by 5%.
The drug was originally developed against the Ebola virus, and has passed Phase I and II clinical trials. Gilead announced the initiation of two Phase III randomized, open-label, multicenter studies, with an aim to enroll approximately 1,000 patients.
In its announcement, Gilead stated that the trials ill take place “at medical centers primarily across Asian countries, as well as other countries globally with high numbers of diagnosed cases.”
Both trials are expected to be completed by the end of April. However, these promising clinical trials seem to be facing troubles with enrolling patients, accoring to Aylward, who stated that this is "not just because the numbers [of infected patients] are falling, but also because we are doing lots of other studies with things that are less promising."
"We have got to start prioritizing enrollment into those things that may save lives and save them faster, and that is a global issue," he added.
Sheng Luo, biostatistics professor at the Duke Clinical Research Institute, broke down the enrollment difficulty to three factors: Firstly, he said that this is due to the enrollment criteria, with the mild / moderate trial requiring the patient to have fewer than eight days since the disease onset, and the severe trial requiring fewer than 12 days.
The second obstacle, according to Luo, is related to the study’s exclusion criteria, since these require that no patient can be on any antivirus medication before the enrollment on the study.
Finally, the third factor affecting the patient recruitment is that most study centers are located in Wuhan, which is the epicenter of the outbreak, and that could limit enrollment.
Moreover, Luo added that the issue could also be due to ‘culture differences’: “In China, people are a bit hesitant about taking medication. They think that there might be some unpredictable side effect,” he said, adding that “If [patients] are mild and moderate, they tend to use their own immune system to fight against the virus.”
Relaxing inclusion or exclusion criteria might be a ‘key’ in resolving the issue, especially due to the pressing timelines, said Luo. However, he added this might cause implications in the study design.