Due to high heterogeneity and risk of bias (RoB) found in previously published meta-analysis (MA), a concrete conclusion on the efficacy of baricitinib in reducing mortality in coronavirus disease 2019 (COVID-19) patients was unable to form. Hence, this systematic review and MA were conducted to analyse whether RoB, heterogeneity, and optimal sample size from placebo-controlled randomized controlled trials (RCTs) are still the problems to derive a concrete conclusion. Search engines PubMed/MEDLINE, ScienceDirect, and other sources like preprints and reference lists were searched with appropriate keywords. The RoB and MA were conducted using RevMan 5.4. The grading of the articles was conducted using the GRADEPro Guideline Development Tool. Ten RCTs were included in the current systematic review. Only five low RoB articles are Phase III placebo-controlled RCTs with a high certainty level based on the GRADE grading system. For the MA, based on five low RoB articles, baricitinib statistically significantly reduced mortality where the risk ratio (RR) = 0.68 [95% confidence interval (95% CI) 0.56-0.82; P
Pyrimethamine (PYR), a STAT3 inhibitor, has been shown to reduce tumour burden in mouse cancer models. It is unclear how much of a reduction occurred or whether the PYR dosages and route of administration used in mice were consistent with the FDA's recommendations for drug repurposing. Search engines such as ScienceDirect, PubMed/MEDLINE, and other databases, including Google Scholar, were thoroughly searched, as was the reference list. The systematic review includes fourteen (14) articles. The risk of bias (RoB) was assessed using SYRCLE's guidelines. Due to the heterogeneity of the data, no meta-analysis was performed. According to the RoB assessment, 13/14 studies fall into the moderate RoB category, with one study classified as high RoB. None adhered to the ARRIVE guideline for transparent research reporting. Oral (FDA-recommended) and non-oral routes of PYR administration were used in mice, with several studies reporting very high PYR dosages that could lead to myelosuppression, while oral PYR dosages of 30 mg/kg or less are considered safe. Direct human equivalent dose translation is probably not the best strategy for comparing whether the used PYR dosages in mice are in line with FDA-approved strength because pharmacokinetic profiles, particularly PYR's half-life (t1/2), between humans (t1/2 = 96 h) and mice (t1/2 = 6 h), must also be considered. Based on the presence of appropriate control and treatment groups, as well as the presence of appropriate clinically proven chemotherapy drug(s) for comparison purposes, only one study (1/14) involving liver cancer can be directed into a clinical trial. Furthermore, oesophageal cancer too can be directed into clinical trials, where the indirect effect of PYR on the NRF2 gene may suppress oesophageal cancer in patients, but this must be done with caution because PYR is an investigational drug for oesophageal cancer, and combining it with proven chemotherapy drug(s) is recommended.