With the number of Covid-19 cases and deaths rising every day in the US, companies and researchers are continuously working to find a vaccine or a therapeutic – drug candidates are currently going the stages of clinical trial testing and investigators are making interim results available while trials are still ongoing. The results from completed trials thus far have provided mixed outcomes. For example, an immunosuppressive drug often touted by US President Donald Trump, hydroxychloroquine, was first approved for the treatment of malaria and is a current treatment for lupus. However, it recently failed to meet endpoints and saw adverse events in a retrospective study conducted at the United States Veterans Health Administration medical centres. Moreover, the patients treated with hydroxychloroquine had a higher mortality rate. Nonetheless, the number of clinical trials investigating hydroxychloroquine or chloroquine as a primary or secondary drug continues to expand.
Currently, 21 ongoing Covid-19 clinical trials have reported interim results. Out of those 21, 16 showed positive early results. These clinical trials are in all phases, with 69% of them in early-stage trials (Phase I to Phase II). The majority of them are investigating different drugs, either alone or in combination treatments, with one using a secondary intervention. The Expanded Access study of Yeliva (opaganib) in subjects with confirmed Covid-19 is using hydroxychloroquine as a secondary intervention. The four multinational clinical trials that are planning to enrol the most subjects, from 140 to 6,000, are investigating remdesivir, sarilumab, and bevacizumab. Two of these multinational trials are sponsored by companies, one is sponsored by an institution, and the other has both kinds of sponsors.
The results from the SIMPLE study, a Phase III ongoing trial by Gilead evaluating the safety and efficacy of remdesivir in patients with severe Covid-19, were announced on April 29, 2020. Remdesivir demonstrated similar clinical improvement in patients receiving a 10-day treatment to those receiving a 5-day treatment. In addition, more than half of the patients were discharged by Day 14 in both treatment groups (60% in 5-day group and 52.5% in 10-day group) while also achieving clinical recovery. Lastly, the drug candidate was well tolerated in both subject groups.
A second clinical trial using remdesivir reported preliminary results on April 29, 2020. The trial, sponsored by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH), reported a 31% faster recovery time over those who received placebo. In addition, the recovery time was 11 days for patients who were treated with remdesivir, compared to 15 days for placebo.
The majority of these trials started in 2020, just after the news broke about the virus. These trials have an estimated end date between April 2020 and March 2021. The two trials ending in late April and the three ending in the month of May will provide more data on the efficacy of the treatments for Covid-19.
Of the two clinical trials that showed early negative results for efficacy and safety, one is a Phase III clinical trial named DCCOVID-19, a Chinese study sponsored by the Shanghai Public Health Clinical Center, evaluating the efficacy and safety of darunavir and cobicistat in the treatment of Covid-19 pneumonia. The other study is a Phase II clinical trial named CloroCOVID19, a Brazilian study sponsored by the Doctor Heitor Vieira Dourado Foundation for Tropical Medicine in collaboration with Fiocruz to evaluate the safety and efficacy of chloroquine for the treatment of hospitalised subjects with severe acute respiratory syndrome secondary to SARS-CoV-2. Both these trials are single-country, institution sponsored, and are studying small molecule drug candidates. Both interventional trials have the same expected end date of 31 August 2020.
Most of these ongoing Covid-19 clinical trials show promising early results, however, conclusions cannot be drawn until final data is reported. There are currently 597 planned clinical trials with 79 of these with an estimated start date in May 2020. With new clinical trials set to begin, and final results expected from ongoing trials as they are completed, GlobalData expects to gain more insight on which key drug candidates could be a potential treatment of Covid-19.