Patent ID: 8840888

Claim:
A method for treating malignant CD19 positive lymphocytes in a human patient identified as having a peripheral blood B:T cell ratio of about 1:5 or lower before treatment to identify patients at risk of developing adverse effects, wherein said B:T cell ratio can be determined by the following steps: i) Determining the total B cell number in a peripheral blood sample of said human patient; ii) Determining the total T cell number in a peripheral blood sample of said human patient; iii) Calculating the ratio of the total B cell number of step i) and the total T cell number of step ii) in order to obtain a B:T cell ratio, said method comprising: (a) administering a first dose of a CD19×CD3 bispecific antibody for a first period of time to said human patient; and consecutively (b) administering a second dose of said antibody for a second period of time to said human patient; wherein said second dose exceeds said first dose, and wherein said CD19×CD3 bispecific antibody is MT103 (Blinatumomab).