The recent PLACID Trial, a large-scale multi-center randomized controlled trial (RCT), has made headlines due to its findings regarding the use of convalescent plasma (CP) as a treatment for Covid-19 patients. Contrary to expectations, the study demonstrated that CP therapy did not yield beneficial effects or improve patient outcomes. Before diving into the details of the study and its implications, let’s understand the basics of an RCT and CP therapy.
Understanding Randomised Controlled Trials and Convalescent Plasma Therapy
An RCT is a scientific approach where subjects are arbitrarily assigned to either an experimental group or a control group. The experimental group receives the intervention being tested, while the control group gets an alternative or conventional treatment.
In the context of the Covid-19 pandemic, CP therapy plays a significant role. CP, obtained from the blood of patients who have recovered from an infection, serves as a reservoir of infection-fighting antibodies. The therapy involves using this antibody-rich blood from recovered individuals to aid others in battling the virus. CP donors must be confirmed Covid-19 cases who have been symptom-free for at least 28 days.
The PLACID Trial: A Deep Dive
The Indian Council of Medical Research (ICMR) conducted the PLACID Trial with the purpose of evaluating the efficacy of CP therapy for treating Covid-19. This trial stands out as the first and most extensive completed randomised control trial globally.
Unfortunately, the trial’s results painted an unremarkable picture for CP therapy. There were no noticeable differences in 28-day mortality rates or the progression from moderate to severe Covid-19 between patients who received CP along with standard care versus those who received standard care alone. While CP appeared to alleviate some symptoms, such as shortness of breath and fatigue, these improvements did not result in reduced mortality or disease severity.
Implications of the PLACID Trial’s Findings
The unexpected results have caused the ICMR to reconsider including CP therapy in national guidelines. The use of CP as a treatment for Covid-19 in India has led to dubious practices such as the solicitation of donors on social media and illicit sales of convalescent plasma.
Even though CP is a safe treatment when administered correctly, it involves resource-heavy processes like plasmapheresis, plasma storage, and measuring neutralising antibodies. Only a limited number of institutes have the capacity to carry out these protocols in a quality-assured manner. Despite these findings, experts warn against outright dismissal of CP therapy, arguing that guidelines are not binding and the research into this therapy is still in its early stages.
Looking Towards the Future
As Covid-19 is a novel virus, new evidence regarding optimal therapeutic approaches continues to emerge globally. Therefore, it may be premature to make definitive decisions about certain treatments. For instance, while the USA’s drug regulator has approved remdesivir, the World Health Organization’s Solidarity Trial found it had minimal effect on 28-day Covid mortality.
Furthermore, personalized care and choosing the right drugs for each patient are integral components of effective Covid-19 treatment. Some therapies could still be practiced on compassionate grounds, and the results from one or two trials should not warrant the discard of an entire treatment or therapy.