4. Discussion
Three parallel studies with a translational approach were conducted to evaluate the hypothesis that androgen inhibition is beneficial in COVID-19. Together, these studies indicate that inhibition of AR signaling with enzalutamide does not appear to confer any beneficial effect in hospitalized patients and does not inhibit SARS-CoV-2 virus replication in lung cells in vitro. In addition, long-term androgen inhibition does not prevent severe COVID-19 disease in the male Swedish population. Contradicting the hypothesis, we observed a prolonged hospital stay among enzalutamide-treated patients in the COVIDENZA trial.
The lack of beneficial effect of enzalutamide on, and perhaps even worsening of, COVID-19 symptoms in the COVIDENZA trial may be explained by its documented induction of CYP3A4 [
[14]- Gibbons J.A.
- de Vries M.
- Krauwinkel W.
- et al.
Pharmacokinetic drug interaction studies with enzalutamide.
], which affects corticosteroid efficacy. Swedish national guidelines as of September 2020 indicate that corticosteroids should be used for the treatment of hospitalized COVID-19 patients on the basis of results from the RECOVERY trial [
[15]- RECOVERY Collaborative Group
- Horby P.
- Lim W.S.
- et al.
Dexamethasone in hospitalized patients with Covid-19.
]. In the present trial, 86% of the patients received corticosteroids. It is possible that enzalutamide-induced CYP3A4 induction could have decreased the efficacy of the cortisone therapy administered, potentially resulting in a worse outcome in the enzalutamide compared to the control arm.
However, in the epidemiological part of our study, we observed a trend towards higher risk of hospitalization in all three treatment groups. The trend strongly suggests that androgen inhibition therapy is not beneficial for COVID-19 outcome, and may indicate that interaction with CYP3A4 was not the only reason for the poor results for enzalutamide treatment in COVIDENZA, since neither group 1 nor group 2 treatments affect CYP3A4.
We observed a higher risk of death from COVID-19 in the group of patients with metastatic prostate cancer treated with ADT in combination with abiraterone/enzalutamide. In Sweden, enzalutamide is almost exclusively used in combination with medical or surgical castration as second- or third-line therapy for metastatic castration-resistant prostate cancer. Since this population is very frail with late-stage metastatic prostate cancer that could be poorly covered by the comorbidity index, it is likely that the higher risk of death is associated with comorbidities and not with the added abiraterone/enzalutamide treatment. In contrast to the present study, a retrospective study of 58 patients with prostate cancer demonstrated that patients with long-term castration therapy exhibited lower risk for both hospitalization and need for oxygen [
[8]- Patel V.G.
- Zhong X.
- Liaw B.
- et al.
Does androgen deprivation therapy protect against severe complications from COVID-19?.
]. The present epidemiological study comprised 7894 patients and investigated the effects of long-term use of androgen inhibition therapy on the risk of requiring intensive care and death, but not oxygen supplementation. Beyond these differences, it is unclear why these two studies had contradictory results. However, the COVIDENZA trial results support a poor outcome after antiandrogen therapy in severe COVID-19.
These results are in contrast to the initial hypotheses, and to the epidemiological data presented by Montopoli et al [
[7]- Montopoli M.
- Zumerle S.
- Vettor R.
- et al.
Androgen-deprivation therapies for prostate cancer and risk of infection by SARS-CoV-2: a population-based study (N = 4532).
] early in the pandemic indicating that prostate cancer patients treated with ADT showed a lower risk of SARS-CoV-2 infection. In addition, a recent study showed a lower risk of SAR-CoV-2 infection after treatment with 5α-reductase inihibitors [
]. This may indicate that limiting androgen signaling could protect against getting infected, but, according to our data, not from being severely affected when already infected.
In COVIDENZA, SARS-CoV-2 levels in nasopharynx swabs decreased at the same rate among enzalutamide-treated patients and patients in the control group. By contrast, a Brazilian study tested the antiandrogen proxalutamide in nonhospitalized patients [
[17]- Cadegiani F.A.
- McCoy J.
- Gustavo Wambier C.
- et al.
Proxalutamide significantly accelerates viral clearance and reduces time to clinical remission in patients with mild to moderate COVID-19: results from a randomized, double-blinded, placebo-controlled trial.
] and found that inhibition of androgen signaling appeared to affect viral internalization. Several experimental studies support a role of androgen inhibition in SARS-CoV-2 virulence [
4- Leach D.A.
- Mohr A.
- Giotis E.S.
- et al.
The antiandrogen enzalutamide downregulates TMPRSS2 and reduces cellular entry of SARS-CoV-2 in human lung cells.
,
18- Qiao Y.
- Wang X.M.
- Mannan R.
- et al.
Targeting transcriptional regulation of SARS-CoV-2 entry factors ACE2 and TMPRSS2.
], although contrasting data also exist [
[19]- Li F.
- Han M.
- Dai P.
- et al.
Distinct mechanisms for TMPRSS2 expression explain organ-specific inhibition of SARS-CoV-2 infection by enzalutamide.
]. The mechanism may be context-dependent, since different species, cell lines, cell types, and model systems generate variable results. However, in line with the COVIDENZA results, the 3D model of primary human lung cells in our study exhibited no enzalutamide-induced decrease in
TMPRSS2 expression or viral load. This finding supports the lack of beneficial clinical effect of enzalutamide in the COVIDENZA trial, and of continuous androgen inhibition in the Swedish population.
In addition to a decrease in viral load, the Brazilian researchers reported a decrease in the risk of hospitalization following proxalutamide treatment of patients with mild COVID-19 [
[20]- McCoy J.
- Goren A.
- Cadegiani F.A.
- et al.
Proxalutamide reduces the rate of hospitalization for COVID-19 male outpatients: a randomized double-blinded placebo-controlled trial.
]. When viewed together with the COVIDENZA results, this indicates that antiandrogen therapy may have a beneficial effect at an early time point in COVID-19 infection, but may be unfavorable in later disease stages when the overactivated immune system contributes to severe symptoms [
[21]- Zhang X.
- Tan Y.
- Ling Y.
- et al.
Viral and host factors related to the clinical outcome of COVID-19.
]. By contrast, the epidemiological part of our study does not support a beneficial role of continuous treatment with either antiandrogens or medical castration. A recent meta-analysis reached the same conclusion [
[22]Karimi A, Nowroozi A, Alilou S, Amini E. Effects of androgen deprivation therapy on COVID-19 in patients with prostate cancer: a systematic review and meta-analysis. Urol J. In press. https://doi.org/10.22037/uj.v18i.6691.
]. If there is a specific window for antiandrogen treatment during the early symptomatic phase of COVID-19, as suggested by the Brazilian study [
17- Cadegiani F.A.
- McCoy J.
- Gustavo Wambier C.
- et al.
Proxalutamide significantly accelerates viral clearance and reduces time to clinical remission in patients with mild to moderate COVID-19: results from a randomized, double-blinded, placebo-controlled trial.
,
20- McCoy J.
- Goren A.
- Cadegiani F.A.
- et al.
Proxalutamide reduces the rate of hospitalization for COVID-19 male outpatients: a randomized double-blinded placebo-controlled trial.
], this would depend on an as yet unknown mechanism for androgen regulation of TMPRSS2, discriminating between the effects of continuous versus short-term antiandrogen treatment.
The present clinical trial used a rather short-term treatment (5 d), which could be a limitation. However, the maximum enzalutamide concentration is reached within 2 h, ensuring a rapid effect on androgen signaling inhibition. Furthermore, we did not want to inflict long-term hormonal effects. The half-life of enzalutamide is approximately 6 d, so we estimate an effect during at least 12 d, which would cover the period within which any treatment effect should be demonstrated.
To the best of our knowledge, this is the first trial evaluating any antiandrogen treatment for female COVID-19 patients. Enzalutamide has been used in a few clinical trials in women with breast cancer (NCT01889238, NCT02007512), which showed that enzalutamide can be safely used in women. The testosterone levels in postmenopausal women are sufficient for activation of AR, which is why the mechanisms could also be valid in women. Therefore, we deemed it unethical to exclude women from a possible treatment effect. An additional rationale was that enzalutamide increases estrogen levels in women [
[23]- Schwartzberg L.S.
- Yardley D.A.
- Elias A.D.
- et al.
A phase I/Ib Study of enzalutamide alone and in combination with endocrine therapies in women with advanced breast cancer.
], and experimental studies in female mice have shown that estrogen decreases SARS-CoV-2 infection [
[24]- Chan J.F.
- Zhang A.J.
- Yuan S.
- et al.
Simulation of the clinical and pathological manifestations of coronavirus disease 2019 (COVID-19) in golden Syrian hamster model: implications for disease pathogenesis and transmissibility.
].
It has previously been shown that comorbidity increases the risk of severe COVID-19 outcomes [
[2]- Williamson E.J.
- Walker A.J.
- Bhaskaran K.
- et al.
Factors associated with COVID-19-related death using OpenSAFELY.
]. This was also seen in the present study, since the risks of hospitalization and death due to COVID-19 increased with the comorbidity score, while the specific risk of being admitted to the ICU was not significantly affected by the comorbidity score. This may be explained by the clinical discrimination in admitting patients to the ICU only if they were expected to benefit from the treatment. It may also be explained by a registration bias due to the establishment of intermediate care units for COVID-19 patients in which high-flow oxygen therapy and intensive monitoring and care are provided, but which are not classified as ICUs in the medical records. Another weakness of the epidemiological study is that we cannot exclude residual confounding.
5. Conclusions
In summary, the present three-pronged study revealed that neither hospitalized COVID-19 patients treated with enzalutamide nor Swedish men with long-term androgen inhibition experienced any benefit in terms of COVID-19 severity. These results are supported by in vitro experiments showing no evidence of enzalutamide affecting SARS-CoV2 infection in human lung cells.
We conclude that enzalutamide should not be used as therapy for severe COVID-19 disease, and that bicalutamide and ADT do not prevent severe COVID-19. Further research on these therapeutics in this setting are not warranted.
Author contributions: Andreas Josefsson had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Josefsson, Welén, Ahlm, Gisslén, Bjartell, Nilsson, Thellenberg Carlsson, Överby, Fors Connolly.
Acquisition of data: Stranne, Bremell, Styrke, Gisslén, Repo, Östholm Balkhed, Niward, Robinsson, Henningsson, Angelin, Lindquist, Rosendal, Lenman, Allard, Becker, Buckland, Rudolfsson, Fonseca-Rodríguez.
Analysis and interpretation of data: Josefsson, Welén, Freyhult, Fors Connolly, Fonseca-Rodríguez, Överby.
Drafting of the manuscript: Josefsson, Welén, Fors Connolly, Överby, Rosendal.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Freyhult, Fonseca-Rodríguez, Rosendal, Lenman.
Obtaining funding: Josefsson, Fors Connolly, Överby, Allard.
Administrative, technical, or material support: Freyhult, Buckland, Rudolfsson, Becker, Lenman.
Supervision: Josefsson, Welén, Fors Connolly, Överby.
Other: None.
Financial disclosures: Andreas Josefsson certifies that all conflicts of interest, including specific financial interests and relationships and affiliations relevant to the subject matter or materials discussed in the manuscript (eg, employment/affiliation, grants or funding, consultancies, honoraria, stock ownership or options, expert testimony, royalties, or patents filed, received, or pending), are the following: Anders Bjartell has received consultant fees and/or honoraria from Ferring, Janssen, AstraZeneca, Astellas, Bayer, Ferring, Ipsen, Sandoz, and Recordati; and participates in DSMB/advisory boards for Bayer, Janssen, AstraZeneca, and Merck. Johan Stranne has received honoraria from Astellas, Bayer, Janssen-Cilag, Ipsen, and Ferring. Magnus Gisslén participates in DSMBs for AstraZeneca and scientific advisory boards for Gilead, GSK/ViiV, and MSD; has received honoraria from Amgen, Biogen, BMS, Gilead, GSK/ViiV, Janssen-Cilag, MSD, Novocure, and Novo Nordic; and has received institutional grants or contracts from Gilead Sciences and Janssen-Cilag. Andreas Josefsson has received an unconditional research grant for COVIDENZA from Astellas Pharma and honoraria from Astellas, Ipsen, Sandoz, and Janssen-Cilag. The remaining authors have nothing to disclose.
Funding/Support and role of the sponsor: This investigator-initiated trial was supported by an unconditional research grant from Astellas Pharma Ltd. The sponsor had no role in the study design; in the data collection, analysis, or interpretation; or in writing the manuscript. AJ is supported by the Knut and Alice Wallenberg Foundation and Swedish Prostate Cancer Federation. KW is supported by the Swedish Cancer Society (CAN 2017/478 and 20 1055 PjF) and the Swedish Prostate Cancer Federation. AKÖ is supported by the Swedish Heart Lung foundation (no. 20200385), and the Knut and Alice Wallenberg Foundation (grants to Science for Life Laboratory, 2020.0182). AMFC is supported by Central ALF-funding, Region Västerbotten (RV-836351), Base unit ALF-funding (RV-939769); Strategic Funding during 2020 from the Department of Clinical Microbiology, Umeå University; and The Laboratory for Molecular Infection Medicine Sweden (MIMS).
Acknowledgments: Support, project management, and facilities to conduct the COVIDENZA trial were provided by the Clinical Research Center at Umeå University Hospital. We thank staff at the clinical trial unit in Umeå (Marja-Liisa Lammi Tavelin, Lisette Marjavaara, Emma Wede, Kristina Öjbrant, Ida Lundström, and Anna Ramnemark) for excellent ongoing help with the startup and continued work with the trial. We also thank the Centre for Clinical Cancer studies at Karolinska Institute for skillful help (Sanna Nyström and Susanne Wallberg). We thank Fredrik Granström at ICT Services and System Development at Umeå University for helping us create the electronic Clinical Report Form, and statistician Professor Marie Eriksson (Umeå University) for help with the randomization process. We also thank all the research personnel for helping with all the work needed to start the COVIDENZA trial at the different sites, and for feedback to help us improve the trial: Frida Samuelsson, Jennie Bobeck, Mia Mickelsson, Helena Gisslén, Jenny Holm Fernström, Ann Carlstrand, Elisabeth Bengtsson, Kristina From, Sofia Sjöberg, Jennifer Amidi, Annika Löfgren, Suzy Lindberg, Malin Karlström, Mathias Cortés Rico, Malin Lindell, Beatrice Backman Lönn, Maria Casserdahl, Kerstin Almroth, Britt-Inger Dahlin, Ester Fridenström, Malin Hellgren, Rebecka Sundén, Ann-Charlotte Borgefeldt, Yvonne Pantzar, and Cecilia Magnusson. We thank the Data Safety and Monitoring Board for external review of COVIDENZA: Associate Professor Martin Eklund, Professor Annika Bergquist, Associate Professor Jan Adolfsson, Professor Lars Hagberg, Professor Jan-Erik Damber, and Senior Medical Advisor Helén Seeman-Lodding. We also thank Sonja Huldén, Judge of Appeal, for legal support. We acknowledge the work of the biobanks in the different regions: Biobank West, Biobank North, Uppsala Biobank, and the Biobank facilities in Sundsvall, Linköping, and Jönköping. We also thank Wolfgang Lohr, Institute of Epidemiology, Umeå University, for data curation in the epidemiological study. We acknowledge the Biochemical Imaging Center at Umeå University and the National Microscopy Infrastructure (VR-RFI 2016-00968) for assistance with microscopy. We thank Anders Blomberg and Gregory Rankin at Umeå University for kindly providing us with lung tissue for HBEC isolation. The computations were performed using resources provided by the Swedish National Infrastructure for Computing through the Uppsala Multidisciplinary Center for Advanced Computational Science under project SNIC 2020/6-251.