QUINAZOLINE DERIVATIVES AND THEIR USE IN THE TREATMENT OF THROMBOCYTHEMIA

1 . A substantially pure form of a compound of the formula

an equilibrating form thereof, a pharmaceutically acceptable salt of the compound or of the equilibrating form thereof,

wherein,

R1 is H, C 1-6 alkyl, C 2-6 alkenyl, C 2-6 alkynyl, C 1-6 alkoxy, or

C 6-10 aryl;

R2 is

R3 is OH, Halogen, SH, O—C 1-6 alkyl or an hydroxymimetic group; and

X and Y are independently H or halogen.

2 . A compound of claim 1 , wherein the compound has the formula

3 . The compound of claim 2 , wherein R2 is

4 . The compound of claim 2 , wherein R1 is H or C 1-6 alkyl.

5 . The compound of claim 2 , wherein R1 is H.

6 . The compound of claim 2 , wherein X is H or halogen.

7 . The compound of claim 2 , wherein Y is H or Cl.

8 . The compound of claim 2 , wherein X is Cl.

9 . The compound of claim 2 , wherein Y is Cl.

10 . The compound of claim 1 , wherein the compound is

11 . A method for the treatment of thrombocythemia comprising administering to a subject in need thereof a therapeutically effective amount of a compound of claim 1 .

12 . The method of claim 11 , wherein the thrombocythemia is associated with essential thrombocythemia (ET), chronic myelogenous leukemia (CML), polycythemia vera (PV), agnogenic myeloid metaplasia (AMM) or sickle cell anemia (SCA).

13 . A method for the treatment of thrombocythemia comprising administering to a subject in need thereof a therapeutically effective amount of a compound as defined in claim 10 .

14 . The method of claim 13 wherein the thrombocythemia is associated with essential thrombocythemia (ET), chronic myelogenous leukemia (CML), polycythemia vera (PV), agnogenic myeloid metaplasia (AMM) or sickle cell anemia (SCA).

15 . A composition comprising at least one compound as defined in claim 1 and at least one therapeutic agent chosen from anagrelide, hydroxyurea, P 32 , busulphan, aspirin, clopidogrel, α-interferon ticlopidine and dipyridamole.