The undersigned organizations and individuals call for a sex and gender approach to clinical trials, diagnosis, prevention, and treatment of diseases. We demand sex and gender tailored drugs and medicines!

Women represent half of the population in the world. But for decades, drugs were approved without being tested on women, putting women at risk. Even when women are adequately represented in clinical research, analysis of data based on gender is unusual[1].

For instance, in relation to COVID/19 “according to an evaluation in preprint of nearly 2500 COVID-19-related studies, less than 5% of investigators had pre-planned for sex-disaggregated data analysis in their studies.”[2][3]

Despite policies in Canada, Europe, and the USA to include sex and gender in medical research, and despite the proven evidence of sex and gender differences on human health, it continues to be understudied, and underutilised in medical and research practice. The beliefs, attitudes, and knowledge of clinicians and researchers regarding the importance of sex and gender in biology, disease, pharmacokinetics and medicine are barriers in addressing these persistent and urgent issues.[4]

Biological sex and gender are relevant, and gender and sex-disaggregated analysis are important, why? A growing body of research highlights the influence of biological sex in clinically relevant health outcomes, including sex-specific differences in immunity, pharmacology, disease and vaccines outcomes (side-effects and efficacy).4  The pharmacokinetics of various therapies appears to differ in men and women, as do response, adherence and adverse reactions.[5]

For instance, in vaccine studies, cisgender females tend to develop higher antibody response and, relatedly, higher efficacy and more side-effects, suggesting the need for sex-differentiated dosing regimens.[6] 

Sex and gender factors, including gender and sex-disaggregated analysis and reporting, are still neglected across the continuum of medicines research and regulation6. This is also the case in COVID-19 trial data reporting6. In this infection, adverse reactions, including clogs, affected disproportionally women.

Despite biological differences between women and men, there are few specific data to guide the care and treatment of women in relation to many diseases, largely because women have been historically under-represented in clinical trials (20–30% in most trials).[1] Consequently, many treatment guidelines contain minimal advice on their care. And, for instance, regarding breastfeeding in context of HIV, more research is needed for women to be confident in their choices and for healthcare professionals to advise.

This puts half of the population at risk.

Therefore, we demand a sex and gender approach to clinical trials, diagnosis, prevention, and treatment of diseases. We demand sex and gender tailored drugs and medicines! Let’s leave behind one size fits all medicine!

Yours sincerely,

Seres (con) viver com o VIH

International Community of Women Living with HIV

[1] Health Decisions. https://www.healthdec.com/the-importance-of-advocating-for-female-participation-in-clinical-trials/ (Accessed 19-04-2021)
[2] Polack FP, Thomas SJ, Kitchin N, et al. Safety and efficacy of the BNT162b2 mRNA Covid-19 vaccine. N Engl J Med. 2020; 383: 2603-2615
[3] Baden LR, El Sahly HM, Essink B, et al. Efficacy and safety of the mRNA-1273 SARS-CoV-2 vaccine. N Engl J Med. 2021; 384: 403-416
[4] Prof Franck Mauvais-Jarvis, MD,  Prof Noel Bairey Merz, MD, et al.  Sex and gender: modifiers of health, disease, and medicine. The Lancet. DOI:https://doi.org/10.1016/S0140-6736(20)31561-0
[5]  Ofotokun et al. Gend Med 2007;4:106-19. Harris, R.Z., Benet, L.Z. & Schwartz, J.B. Gender Effects in Pharmacokinetics and Pharmacodynamics. Drugs 50, 222–239 (1995). https://doi.org/10.2165/00003495-199550020-00003
[6] L. Vijayasingham, E. Bischof, J. Wolfe. Sex-disaggregated data in COVID-19 vaccine trials. The Lancet. 2021. DOI:https://doi.org/10.1016/S0140-6736(21)00384-6
[7] Sergey Feldman, PhD1; Waleed Ammar, PhD1; Kyle Lo, MS1; et al. Quantifying Sex Bias in Clinical Studies at Scale With Automated Data Extraction. JAMA Netw Open. 2019;2(7):e196700. doi:10.1001/jamanetworkopen.2019.6700

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