"Cell therapy has advanced significantly in recent years and has been used to treat cancer and auto-immune, heart and infectious diseases. During the pandemic, it was used to treat COVID-19 in several clinical trials," said Otávio Cabral-Marques, a professor at USP's Medical School and coordinator of the study.
Stem cell therapy and models involving organoids derived from stem cells drew a great deal of attention as novel methods for treating and studying COVID-19 during the pandemic, he noted, given the significant immune regulatory power and tissue repair functions of stem cells, especially the mesenchymal variety.
The authors also note differences in terms of the phases of trials. In many countries, especially in Europe, strict regulation limits the number of human cell therapy products with established safety profiles that can be trialed, and 56% of the trials did not reach phase 2, which typically focuses on determining safety, efficacy and dose-response in a few hundred volunteers with the disease. Another limitation was that 31% of the trials analyzed did not have a control group.
"There are techniques to standardize the data, eliminate biases and produce an impartial result, enabling analysts to reach conclusions that often go unnoticed in a specific study but add up to relevant scientific evidence when they are reinforced by other data," said Dennyson Leandro M. Fonseca, another co-author.