King's College London

Research portal

Mendelian randomisation and experimental medicine approaches to interleukin-6 as a drug target in pulmonary arterial hypertension

Research output: Contribution to journalArticlepeer-review

Uniphy Clinical Trials Network

Original languageEnglish
Article number2002463
JournalThe European respiratory journal
Issue number3
Early online date10 Mar 2022
Accepted/In press15 Jul 2021
E-pub ahead of print10 Mar 2022

Bibliographical note

Funding Information: Conflict of interest: M. Toshner reports grants and personal fees from Bayer and Actelion, and personal fees from MSD and GSK, during the conduct of the study, and serves on the advisory board for MorphogenIX. C. Church has received travel grants and speaker fees from GSK, Actelion and Bayer. L. Harbaum has nothing to disclose. C. Rhodes reports personal fees for advisory board work from Actelion and United Therapeutics, outside the submitted work. S.S. Villar Moreschi has nothing to disclose. J. Liley has nothing to disclose. R. Jones has nothing to disclose. A. Arora has nothing to disclose. K. Batai has nothing to disclose. A.A. Desai has nothing to disclose. J.G. Coghlan reports research support, consultancy fees and speaker honoraria from Actelion. J.S.R. Gibbs reports personal fees from Acceleron, Arena, Bayer, Bellepheron, Complexa, Pfizer and United Therapeutics, grants and personal fees from Actelion, and personal fees and non-financial support from GSK, outside the submitted work. D. Gor was an employee of Roche, during the conduct of the study. S. Gräf has nothing to disclose. L. Harlow has nothing to disclose. J. Hernandez-Sanchez is an employee of Roche but was not at the time of trial conduct. L.S. Howard has received personal fees and institutional grants/research support from Bayer and personal fees from MSD, Daichii Sayo and Pfizer. M. Humbert has received personal fees from Actelion, Merck and United Therapeutics, and grants and personal fees from Bayer and GSK. J. Karnes has nothing to disclose. D.G. Kiely reports grants and personal fees from Bayer and Actelion, and personal fees from GSK and MSD, during the conduct of the study. R. Kittles has nothing to disclose. E. Knightbridge has nothing to disclose. B. Lam has nothing to disclose. K.A. Lutz has nothing to disclose. W.C. Nichols has nothing to disclose. M.W. Pauciulo has nothing to disclose. J. Pepke-Zaba has served on advisory boards of and received personal fees and institutional grant/research support from Actelion, Bayer, MSD and GSK. J. Suntharalingam has nothing to disclose. F. Soubrier has nothing to disclose. R.C. Trembath has nothing to disclose. T-H.L. Schwantes-An has nothing to disclose. S.J. Wort reports grants and personal fees from Actelion and Bayer, and personal fees from GSK and MSD, outside the submitted work. M.R. Wilkins has nothing to disclose. S. Gaine has received honoraria from Actelion and United Therapeutics; has received travel grants from Actelion, Novartis and Menerini; and has performed drug safety board monitoring for United Therapeutics, GSK and Novartis. N.W. Morrell reports personal fees from MorphogenIX, during the conduct of the study. P.A. Corris has served on speakers’ bureau and advisory boards of Actelion, Bayer and MSD, and received institutional grant/research support from Actelion and Bayer. Funding Information: Support statement: This work was funded by a grant from the UK National Institute of Health Research Cambridge Biomedical Research Centre and Rare Diseases Translational Research Collaboration, in addition to an unrestricted grant from Roche Products Limited, Welwyn Garden City, UK. TRANSFORM-UK, number NCT02676947. Funding information for this article has been deposited with the Crossref Funder Registry. Publisher Copyright: © 2022 European Respiratory Society. All rights reserved.


King's Authors


BACKGROUND: Inflammation and dysregulated immunity are important in the development of pulmonary arterial hypertension (PAH). Compelling preclinical data supports the therapeutic blockade of interleukin-6 (IL-6) signalling. METHODS: We conducted a phase 2 open-label study of intravenous tocilizumab (8 mg·kg-1) over 6 months in patients with group 1 PAH. Co-primary end-points were safety, defined by incidence and severity of adverse events, and change in pulmonary vascular resistance. Separately, a mendelian randomisation study was undertaken on 11 744 individuals with European ancestry including 2085 patients with idiopathic/heritable disease for the IL-6 receptor (IL6R) variant (rs7529229), known to associate with circulating IL-6R levels. RESULTS: We recruited 29 patients (male/female 10/19; mean±sd age 54.9±11.4 years). Of these, 19 had heritable/idiopathic PAH and 10 had connective tissue disease-associated PAH. Six were withdrawn prior to drug administration; 23 patients received at least one dose of tocilizumab. Tocilizumab was discontinued in four patients owing to serious adverse events. There were no deaths. Despite evidence of target engagement in plasma IL-6 and C-reactive protein levels, both intention-to-treat and modified intention-to-treat analyses demonstrated no change in pulmonary vascular resistance. Inflammatory markers did not predict treatment response. Mendelian randomisation did not support an effect of the lead IL6R variant on risk of PAH (OR 0.99, p=0.88). CONCLUSION: Adverse events were consistent with the known safety profile of tocilizumab. Tocilizumab did not show any consistent treatment effect.

Download statistics

No data available

View graph of relations

© 2020 King's College London | Strand | London WC2R 2LS | England | United Kingdom | Tel +44 (0)20 7836 5454