Withania somnifera as a safer option to hydroxychloroquine in the chemoprophylaxis of COVID-19: Results of interim analysis

Objectives: To study the efficacy and safety of Withania somnifera (WS, Ashwagandha) in the prophylaxis against COVID-19 in high risk health care workers (HCW) in comparison to hydroxychloroquine (HCQ). To evaluate the general physical and mental health benefits of Ashwagandha.

Methods: A 16 week randomized prospective, open-label, parallel efficacy, two arm, multi-centre study. The primary efficacy measure was 'failure of prophylaxis' as confirmed COVID-19 by quantitative Reverse Transcription Polymerase Chain Reaction (RT-PCR) at any time during the study period. This study on 400 participants from three centres was designed to establish non-inferiority for WS to HCQ for prophylaxis against COVID-19 at 80 % power and significance p < 0.025, one-sided. The interim analysis was carried out on 160 participants after completion of 8 weeks.

Results: Participants in both the arms were well-matched at the baseline characteristics. Forty participants in the HCQ group and 26 participants in the WS group reported mild AE. The symptoms of confirmed COVID-19 were found to be 3.7 % (95 % CI 1.3-10.5 %) in the HCQ and 1.3 % (95 % CI 0.02-6.7 %) in the WS arm amongst the first 160 participants completing 8 weeks.

Conclusion: Our intent was to explore a safer option to HCQ. We report that WS was not found inferior to HCQ and its efficacy was within the 15 % non-inferiority margin set a priori. WS as an immunomodulator has other clinical benefits including reducing mental stress. The final report of this study is expected by end of August 2021.