METHOD TO OPTIMIZE THE TREATMENT OF PATIENTS WITH BIOLOGICAL DRUGS

1 . A method for classifying a patient suffering from rheumatoid arthritis as a responder or as a non-responder patient to a treatment, said treatment comprising the administration to said patient of a biological drug selected from the group consisting of infliximab and adalimumab that is periodically administered by repetitive administrations, and wherein said patient has received at least one dose from said biological drug, said method comprising the steps of:

a) determining the concentration of the circulating biological drug in a sample from said patient at a time t 1 wherein said t 1 corresponds to a time point within the period of time between two successive administrations of said biological drug;

b) determining the concentration of antibodies against said biological drug in a sample from said patient at a time t 1 ; and

c) comparing the concentration of the circulating biological drug at said t 1 with a Reference Value 1 (RV 1 ) and the concentration of antibodies against said biological drug at said time t 1 with a Reference Value 2 (RV 2 ),

wherein

the sample is selected from a sample of blood, a sample of plasma and a sample of serum;

RV 1 is a therapeutic efficiency cut-off value of the concentration of the circulating biological drug; and

RV 2 is the cut-off value of the concentration of said antibody against the biological drug as determined in a group of treatment-naïve individuals by the same assay as that used for determining the concentration of the antibody against the biological drug in step b), and

wherein if the concentration of the circulating biological drug is lower than RV 1 and the concentration of antibodies against said biological drug is higher than RV 2 , then said patient is classified as a non-responder patient to said treatment, and

wherein if the concentration of the circulating biological drug is equal to, or higher than RV 1 and the concentration of antibodies against said biological drug is equal to, or lower than, RV 2 , then said patient is classified as a responder patient to said treatment, and

wherein if the biological drug is infliximab, then RV 1 is 1.5 μg/ml; and

wherein if the biological drug is adalimumab, then RV 1 is 0.8 μg/ml.

2 . The method according to claim 1 , wherein said t 1 is a time point within two weeks of the administration of the biological drug.

3 . The method according to claim 1 , wherein the concentration of the circulating biological drug is determined by an immunoassay.

4 . The method according to claim 1 , wherein the concentration of antibodies against said biological drug is determined by an immunoassay.

5 . The method according to claim 3 , wherein the immunoassay is an ELISA.

6 . The method according to claim 4 , wherein the immunoassay is an ELISA.

7 . The method according to claim 1 , wherein said t 1 is a time point within one week of the administration of the biological drug.

8 . The method according to claim 1 , wherein if the biological drug is infliximab, then RV 2 is 150 ng/ml, and wherein if the biological drug is adalimumab, then RV 2 is 32 ng/ml.

9 . A method for treating a patient suffering from rheumatoid arthritis, comprising:

a) administering to said patient a biological drug at a time, ti, wherein the biological drug is selected from the group consisting of infliximab and adalimumab;

b) determining the concentration of the circulating biological drug in a sample from said patient at a time, ti, wherein t 1 is a time point after ti;

c) determining the concentration of antibodies against said biological drug in a sample from said patient at t 1 ; and

d) comparing the concentration of the circulating biological drug at ti with a Reference Value 1 (RV 1 ) and the concentration of antibodies against said biological drug at t 1 with a Reference Value 2 (RV 2 ),

wherein:

the sample is selected from a sample of blood, a sample of plasma and a sample of serum;

RV 1 is a therapeutic efficiency cut-off value of the concentration of the circulating biological drug;

RV 2 is the cut-off value of the concentration of said antibody against the biological drug as determined in a group of treatment-naïve individuals by the same assay as that used for determining the concentration of the antibody against the biological drug in step c);

wherein if the concentration of the circulating biological drug is equal to, or higher than RV 1 and the concentration of antibodies against said biological drug is equal to, or lower than, RV 2 , then classifying the patient as a responder and repeating step a); and

wherein if the concentration of the circulating biological drug is equal to, or higher than RV 1 and the concentration of antibodies against said biological drug is equal to, or lower than, RV 2 , then classifying the patient as a non-responder and revising treatment.

10 . The method according to claim 9 , wherein t 1 is a time point within two weeks of ti.

11 . The method according to claim 9 , wherein t 1 is a time point within one week of ti.

12 . The method according to claim 9 , wherein the concentration of the circulating biological drug is determined by an immunoassay.

13 . The method according to claim 12 , wherein the immunoassay is an ELISA.

14 . The method according to claim 9 , wherein the concentration of antibodies against said biological drug is determined by an immunoassay.

15 . The method according to claim 14 , wherein the immunoassay is an ELISA.

16 . The method according to claim 1 , wherein if the biological drug is infliximab, then RV 1 is 1.5 μg/ml, and wherein if the biological drug is adalimumab, then RV 1 is 0.8 μg/ml.

17 . The method according to claim 16 , wherein if the biological drug is infliximab, then RV 2 is 150 ng/ml, and wherein if the biological drug is adalimumab, then RV 2 is 32 ng/ml.