ADAs to Alemtuzumab

Primary To quantify the longitudinal changes in alemtuzumab ADAs over a 24 month period.

Secondary

• Relative occurrence of infusion-related reactions based on high alemtuzumab ADA levels prior to course 2.
• Relative change in lymphocyte counts after the second infusion of alemtuzumab in ADA positive patients to assess the health economic impact of infusion-related reactions.
• Relative change in relapses or EDSS score based on alemtuzumab ADA levels to assess the health economic impact of disease activity.
• Relative change in relapses or EDSS score based on alemtuzumab ADA levels.
• Relative change in T2 lesion number or Gd-enhancing lesions, and serum NfL based on alemtuzumab ADA levels to assess the health economic impact of disease activity.

Inclusion criteria

• Patients with RRMS who are being treated with alemtuzumab at Barts Health NHS Trust will be approached to participate in the study.
• Patients must be willing and able to undergo blood tests.

Exclusion criteria

• Ineligible for alemtuzumab under NHS England prescribing guidelines.
• Those unable to comply with study requirements, including frequency of visits. Abnormal baseline investigations (WBC<3 x 10*9/l, lymphocytes <1.0 x 10*9/l, neutrophil count <1.5 x 10*9/l, platelet count <100 x 10*9/l, haemoglobin <110 g/l, LFT >/3x upper limit of normal of site reference ranges, potassium <2.8 mmol/l or >5.5 mmol/l, sodium /,125 mmol/l, creatinine >130 umol/l).