Article Text

Download PDFPDF
WED 186 Effect of cladribine tablets on immune cells in patients with ms
  1. Olaf Stuve1,
  2. Per Soelberg-Sorensen2,
  3. Gavin Giovannoni3,
  4. Thomas Leist4,
  5. Yann Hyvert5,
  6. Doris Damian5,
  7. Ursula Boschert5
  1. 1University of Texas, Southwestern Medical Center, Dallas, TX, USA
  2. 2Department of Neurology, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark
  3. 3Blizard Institute, Barts and The London School of Medicine and Dentistry, London, UK
  4. 4Thomas Jefferson University, Comprehensive MS Center, Jefferson Medical College, PA, USA
  5. 5EMD Serono Research and Development Institute, Inc., a business of Merck KGaA, Darmstadt Germany


Background Cladribine tablets 3.5 mg/kg (CT3.5) demonstrated efficacy in patients with early (ORACLE-MS) and relapsing MS (CLARITY/CLARITY-Extension).

Objective Evaluate B, T lymphocyte and natural killer (NK) cell profiles after CT administration in ORACLE-MS, CLARITY and CLARITY-Extension.

Methods Longitudinal evaluation of peripheral blood lymphocytes was conducted for patients receiving the CT (either part of the initial 3.5 mg/kg active treatment groups or placebo switched to active treatment). Absolute lymphocyte counts (ALC) and subtype dispositions were evaluated at baseline, and Weeks 5, 13, 24, 48.

Results Baseline distributions of ALC and temporal profiles of CD19+ B and CD4+ and CD8+ T lymphocytes were generally consistent across studies. Rapid reductions were observed for CD19+ B cells (~75% reduction; Week 5), with nadirs at Week 13 (~80% reduction). Reconstitution of CD19+ B cells towards baseline occurred from Week 24–48. Lesser, discontinuous reductions also occurred for CD4+ and CD8+ T cells that had not fully returned to baseline by Week 48. CD16+/CD56+ NK cells were transiently reduced with CT, with recovery evident at Weeks 24 (29%) and 48 (23%).

Conclusions CT3.5 achieved early, discontinuous reduction of peripheral blood B cells, with rapid reconstitution towards baseline; a moderate, discontinuous reduction of T cells; and early, transient NK cell reductions.


Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.