title: Severity of the TGN1412 trial disaster cytokine storm correlated with IL-2 release.
abstract: OBJECTIVE
  To determine if cytokine release with a solid phase assay is predictive of adverse responses for a range of therapeutic mAbs.
  
  
  METHODS
  Cytokine ELISAs and a multi-array system were used to compare responses generated by different therapeutic mAbs using a solid phase assay. Flow cytometry was employed to determine the cellular source of those cytokines.
  
  
  RESULTS
  Only TGN1412 and muromonab-CD3 stimulated CD4+ T-cell mediated cytokine release characterized by significant (all P < 0.0001) IFNγ, TNFα, IL-2, IL-4, IL-5, IL-10, IL-12, IL-13, IL-17 and IL-22 release, comparable with T-cell mitogen. Significantly greater (P < 0.0001) IL-2 release with TGN1412 (2894-6051 pg ml⁻¹) compared with muromonab-CD3 (62-262 pg ml⁻¹) differentiated otherwise comparable cytokine responses. Likewise, TGN1412 stimulated significantly more (P = 0.0001) IL-2 producing CD4+ T-cells than muromonab-CD3 and induced Th1, Th2, Th17 and Th22 subsets that co-release this cytokine. Significant TNFα release was observed with bevacizumab (P = 0.0001), trastuzumab (P = 0.0031) and alemtuzumab (P = 0.0177), but no significant IL-2 release. TGN1412 and muromonab-CD3 caused pro-inflammatory cytokine release despite significantly (both P < 0.0001) increasing numbers of T-cells with a regulatory phenotype.
  
  
  CONCLUSIONS
  The severity of the adverse response to TGN1412 compared with muromonab-CD3 and other therapeutic mAbs correlates with the level of IL-2 release.
authors.affiliation: Biotherapeutics Group, NIBSC, Potters Bar, Hertfordshire, UK.
authors.forename: David
authors.initials: D
authors.lastname: Eastwood
authors.forename: Chris
authors.initials: C
authors.lastname: Bird
authors.forename: Paula
authors.initials: P
authors.lastname: Dilger
authors.forename: Jason
authors.initials: J
authors.lastname: Hockley
authors.forename: Lucy
authors.initials: L
authors.lastname: Findlay
authors.forename: Stephen
authors.initials: S
authors.lastname: Poole
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Thorpe
authors.forename: Meenu
authors.initials: M
authors.lastname: Wadhwa
authors.forename: Robin
authors.initials: R
authors.lastname: Thorpe
authors.forename: Richard
authors.initials: R
authors.lastname: Stebbings
mesh_terms: D000911:Antibodies, Monoclonal / Q000009:adverse effects* / Q000276:immunology; D061067:Antibodies, Monoclonal, Humanized / Q000009:adverse effects* / Q000276:immunology; D002986:Clinical Trials as Topic; D016207:Cytokines / Q000187:drug effects / Q000276:immunology*; D064420:Drug-Related Side Effects and Adverse Reactions / Q000517:prevention & control; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006801:Humans; D007376:Interleukin-2 / Q000276:immunology*; D016853:Muromonab-CD3 / Q000009:adverse effects* / Q000276:immunology; D012107:Research Design / Q000592:standards*; D018570:Risk Assessment
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D016207:Cytokines; D007376:Interleukin-2; D016853:Muromonab-CD3; C509303:TGN-1412
keywords: TGN1412; cytokine release assays; preclinical safety testing; therapeutic monoclonal antibodies