Patent ID: 8367363

Claim:
An in vitro prognostic assay useful for predicting the in vivo therapeutic responsiveness of a disease or disorder, having an etiology associated with excessive cell proliferation, to treatment with a cardiac glycoside or composition comprising a cardiac glycoside, the assay comprising: determining the ratio of α3 isoform to α1 isoform of Na, K-ATPase α-subunit in a sample obtained from diseased in vivo cellular tissue of a subject with a disease or disorder having an etiology associated with excessive cell proliferation, the sample comprising one or more isoforms of the α-subunit of Na, K-ATPase, wherein the step of determining said ratio comprises quantifying the level of expression of each of the α3 subunit isoform of Na, K-ATPase and the α1 subunit isoform of Na, K-ATPase in the in vitro sample or biopsy sample, and calculating the ratio thereof; or the step of determining the ratio comprises determining the amount of each of the α3 subunit isoform of Na, K-ATPase relative to amount of the α1 subunit isoform of Na, K-ATPase in the in vitro sample, and calculating the ratio thereof; and determining the probability of a therapeutic response according to said ratio of α3 isoform to α1 isoform of Na, K-ATPase in the subject were the subject to be treated with a therapeutically relevant dose of said cardiac glycoside according to a prescribed dosing regimen, wherein the probability is determined according to the following table: Probability that there will be a therapeutic Ratio response in the subject 0.3-0.45 +/− 0.05 20-<30% 0.5-0.95 +/− 0.05 30-50% >/=1 +/− 0.05 >50% >10 >75%.