A Study To Evaluate The Safety And Tolerability Of PF-06342674 (RN168) In Subjects With Multiple Sclerosis (MS)

An AE was any untoward medical occurrence in a participant who received study drug. An SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. Treatment-emergent AEs are events between first dose of study drug and up to Day 127/Early Termination that were absent before treatment or that worsened relative to pretreatment state. AEs included both SAEs and non-SAEs.

AE severity was graded as mild, moderate, or severe. Mild AEs do not interfere with the participant's usual function. Moderate AEs interfere to some extent with the participant's usual function. Severe AEs interfere significantly with the participant's usual function.

Number of participants with laboratory test abnormalities without regard to baseline abnormality. Laboratory test parameters included hematology, liver function, renal function, electrolytes, hormones, clinical chemistry, and urinalysis (dipstick and microscopy). Abnormal laboratory findings included: lymphocytes (absolute) less than (<)0.8 x lower limit of normal (LLN); urine blood/hemoglobin (qualitative) more than or equal to (>=)1; urine nitrite >=1; urine leukocyte esterase >=1; urine red blood cell (RBC) >=20/high-power field (HPF).

Categorical summarization criteria in vital signs included: supine systolic blood pressure (SBP) of <90 millimeters of mercury (mm Hg) or change in supine SBP of >=30 mm Hg; supine diastolic blood pressure (DBP) of <50 mm Hg or change in supine DBP of >=20 mm Hg; supine pulse rate of <40 or more than (>)120 beats per minute (bpm).

Criteria for potential clinical concern in ECG parameters: The maximum of the beginning of the Q wave to the end of the T wave corresponding to electrical systole (QT) interval corrected using the Fridericia formula (QTcF) >=450 milliseconds (msec), maximum QTcF interval change from baseline in range of 30 to <60 msec and >=60 msec.

Assays for the determination of a positive immune response was performed. An antibody immune response was defined as a confirmed post-treatment positive enzyme-linked immunosorbent assay (ELISA) result in combination with a negative baseline sample ELISA result. ADA positive was defined as ADA titer (ie, the reciprocal of the highest dilution that gives a value equivalent to the cut point of the assay) >=4.32.