Potential therapies to defeat coronavirus

Medical staff in protective suits treat coronavirus patients in an intensive care unit at the Cremona Hospital in northern Italy, in this still image taken from a video, on Thursday. [Reuters]

Here are some drugs and therapies that have been recommended by experts, and some drugs that have been found to have the potential to defeat the novel coronavirus (Covid-19) and have entered clinical trials.

Chloroquine phosphate

Chloroquine Phosphate, a widely used anti-malaria and autoimmune disease drug, has been used for more than 70 years. The drug has been used in treating 285 critically ill Covid-19 patients in a hospital in Wuhan, and no obvious adverse reactions have been found so far.

In the latest version of the treatment guideline, Chloroquine Phosphate is recommended for Covid-19 patients aged from 18 to 65 years. The amount for patients over 50kg is 500 mg per dose twice a day for seven days. The guideline also noted that patients should take less than three antiviral drugs.

Tocilizumab

Tocilizumab, with the common brand name Actemra, is an injectable synthetic protein that blocks the effects of IL-6 in patients with rheumatoid arthritis. IL-6 is a protein that the body produces when there is inflammation. The latest version of the guideline suggests the use of Tocilizumab in patients with an increasing level of IL-6 and with extensive lesions in both lungs or severe symptoms.

Chinese researchers have found that a cause of death for severe and critically ill patients infected with the novel coronavirus is cytokine storm, an overreaction of the immune system. These patients are found with a higher level of IL-6 in their blood. Last month, the increasing level of IL-6 was recommended as a warning sign that the patient’s situation could possibly deteriorate. Currently, the drug is under clinical trials in 14 hospitals in Wuhan and a total of 272 severe patients had been treated with Tocilizumab as of March 5.

Convalescent plasma

Convalescent plasma, processed from the plasma collected from recovered Covid-19 patients, contains a large number of protective antibodies. As of February 28, some 245 Covid-19 patients have received the therapy and 91 cases have shown improvement in clinical indicators and symptoms. According to health authorities, plasma therapy has proved safe and effective.

Traditional Chinese medicine

Traditional Chinese medicine (TCM) has been proven effective in treating Covid-19 patients. With TCM treatment, patients with mild symptoms have seen their fever or cough alleviated, according to medical experts. For severely ill patients, TCM helped relieve symptoms and restore blood oxygen saturation, preventing the patients’ conditions from developing into critically ill cases. TCM decoction Qingfei Paidu Soup was recommended to medical institutions nationwide on February 6 after data analysis on 214 cases. As of February 29, the decoction has been used in 66 designated hospitals in 10 provincial-level regions in China.

Drugs under trial

Favipiravir, an influenza drug available on overseas markets, has been put in a parallel controlled study in Shenzhen, Guangdong Province, with 80 patients enlisted. The initial outcome of the trial shows the drug has relatively obvious efficacy and low adverse reactions. Experts have suggested expanding the trial to further observe and study its effect. Remdesivir, developed against Ebola infections by American pharmaceutical company Gilead Sciences, has shown fairly good antiviral activity against the novel coronavirus at the cellular level. Cao Bin, a respiratory expert who is leading the Remdesivir program, said last Wednesday that two trials for Remdesivir are going on smoothly and China will share the data with the international community after the programme is completed.

Stem cell trial

Clinical studies on stem cell therapy, which can inhibit the overreaction of the body’s immune system, have also been carried out to treat severe patients.

As of February 21, four patients who have received the therapy have been discharged from hospital, and the trial is expected to be further expanded.  Currently, three kinds of stem cells - mesenchymal, lung and embryonic stem cells - are used in treatments. Researchers usually inject stem cell products into the lungs.

Meanwhile, the Chinese Academy of Sciences has developed a new stem cell drug, CAStem, which has shown promising results in animal experiments.

Several research and trials on applying stem cells to treat covid-19 patients have been carried out in China.