A CISF officer checks the temperature of a visitor at the Red Fort on the first day of its reopening after the lockdown. Photo: PTI
As India explores different therapies to treat Covid-19, results from the Indian Council of Medical Research’s (ICMR’s) convalescent plasma therapy (CPT) trials are expected in a couple of weeks, claim sources at clinical trial sites.
So far, the results are mixed — while some patients have recovered, there have also been cases of conditions worsening.
The trial, taking place across 50 sites in India, has collected data from 350-odd patients. The sample size for the trial is 425 patients and the results are likely to be announced soon, said a source at a Gujarat-based site. CPT is being used in India on compassionate grounds by doctors and is also a part of the ICMR’s clinical management protocol of Covid-19. In this experimental therapy, blood plasma from a Covid-19 recovered patient (which is rich in antibodies to fight the virus) is transfused into another Covid patient. This is likely to boost the recipient’s immune response to the SARS-CoV-2 infection.
Two sites in Ahmedabad (NHL Medical College and BJ Medical College), which are conducting the ICMR trials on CPT, have shown positive results, said sources. According to them, fair amounts of some patients have shown recovery under the trials that are likely to conclude in a week or two.
“While the exact results cannot be shared since ICMR would declare them after the trials conclude, initial observations show a fair amount of patients on recovery mode though there have also been cases of conditions worsening. With already 350 patients enrolled for plasma trials against the target of 425 across roughly 50 centres, the trials are likely to go on for another week or so before ICMR declares the results,” said sources at one of the centres in Ahmedabad.
Around 25 patients have been enrolled at NHL Medical College with half of them put on controlled standard care in order to compare them with the other half undergoing plasma intervention. So far, over 30 plasma donors have been enrolled.
Meanwhile, there has been some confusion on who should be given CPT. Doctors have advised using CPT earlier in patients (moderately sick) and not wait till it becomes a severe condition. As for the therapeutic off-label use of plasma among Covid patients, centres in Gujarat have stuck to those with mild to moderate conditions. The centres are awaiting bio-markers that can help test antibodies in patients in order to decide whether to administer plasma or not.
Satyanarayana Mysore, head of department of interventional pulmonology, Manipal Hospitals, said: “Mild patients should not be given CPT as they recover easily. CPT is reserved for moderate to severe patients where we see the oxygen saturation levels going down and the pulse rate going up.”
He felt it should be given to a patient to whom drugs like tocilizumab or remdesivir do not show positive results. Plasma is like a readymade kit containing antibodies that are directed towards the virus, Mysore added. “We are trying to negate the viral load in an individual over a period of four hours and reduce the viral replication. So, the immune system, which is over-reacting to the virus, automatically quiets down thinking that it has beaten the virus,” he said.
The larger challenge is finding a donor. Even the clinical trial sites are facing challenges while collecting blood plasma.
“Selection of donors and patients is a challenge. The other challenge has been in terms of several donors’ inability to fulfil other criteria such as haemoglobin level of 12.5 and weight above 50 kg after recovery,” said sources at BJ Medical College.
Mysore highlighted that apart from availability (linked to social issues as recovered patients do not want to donate thinking they will become weak), there is an issue of selectivity too.
“We cannot take blood from multiferous women (who have had multiple child births) and women past 40 years. They will have pre-formed antibodies at each childbirth and they will interfere with the Covid-19 antibodies. They are not the ideal donors,” he said.