DEUTERIUM-ENRICHED IXABEPILONE

1 . A deuterium-enriched compound of formula I or a pharmaceutically acceptable salt thereof:

wherein R 1 -R 42 are independently selected from H and D; and the abundance of deuterium in R 1 -R 42 is at least 2%.

2 . A deuterium-enriched compound of claim 1 , wherein the abundance of deuterium in R 1 -R 42 is selected from at least 2%, at least 5%, at least 10%, at least 14%, at least 19%, at least 24%, at least 29%, at least 33%, at least 38%, at least 43%, at least 48%, at least 52%, at least 57%, at least 62%, at least 67%, at least 71%, at least 76%, at least 81%, at least 86%, at least 90%, at least 93%, at least 98%, and 100%.

3 . A deuterium-enriched compound of claim 1 , wherein the abundance of deuterium in R 1 -R 3 is selected from at least 33%, at least 67%, and 100%.

4 . A deuterium-enriched compound of claim 1 , wherein the abundance of deuterium in R 4 -R 5 is selected from at least 50% and 100%.

5 . A deuterium-enriched compound of claim 1 , wherein the abundance of deuterium in R 6 -R 34 is selected from at least 3%, at least 7%, at least 14%, at least 21%, at least 28%, at least 34%, at least 41%, at least 48%, at least 55%, at least 62%, at least 69%, at least 76%, at least 83%, at least 90%, at least 97%, and 100%.

6 . A deuterium-enriched compound of claim 1 , wherein the abundance of deuterium in R 35 -R 38 is selected from at least 20%, at least 40%, at least 60%, at least 80%, and 100%.

7 . A deuterium-enriched compound of claim 1 , wherein the abundance of deuterium in R 39 is selected from at least 100%.

8 . A deuterium-enriched compound of claim 1 , wherein the abundance of deuterium in R 40 -R 42 is selected from at least 33%, at least 67%, and 100%.

9 . A deuterium-enriched compound of claim 1 , wherein the compound is selected from compounds 1-7 of Table 1.

10 . A deuterium-enriched compound of claim 1 , wherein the compound is selected from compounds 8-14 of Table 2.

11 . An isolated deuterium-enriched compound of formula I or a pharmaceutically acceptable salt thereof:

wherein R 1 -R 42 are independently selected from H and D; and the abundance of deuterium in R 1 -R 42 is at least 2%.

12 . An isolated deuterium-enriched compound of claim 11 , wherein the abundance of deuterium in R 1 -R 42 is selected from at least 2%, at least 5%, at least 10%, at least 14%, at least 19%, at least 24%, at least 29%, at least 33%, at least 38%, at least 43%, at least 48%, at least 52%, at least 57%, at least 62%, at least 67%, at least 71%, at least 76%, at least 81%, at least 86%, at least 90%, at least 93%, at least 98%, and 100%.

13 . An isolated deuterium-enriched compound of claim 11 , wherein the abundance of deuterium in R 1 -R 3 is selected from at least 33%, at least 67%, and 100%.

14 . An isolated deuterium-enriched compound of claim 11 , wherein the compound is selected from compounds 1-7 of Table 1.

15 . An isolated deuterium-enriched compound of claim 11 , wherein the compound is selected from compounds 8-14 of Table 2.

16 . A mixture of deuterium-enriched compounds of formula I or a pharmaceutically acceptable salt thereof:

wherein R 1 -R 42 are independently selected from H and D; and the abundance of deuterium in R 1 -R 42 is at least 2%.

17 . A mixture of deuterium-enriched compound of claim 16 , wherein the compound is selected from compounds 1-7 of Table 1.

18 . A mixture of deuterium-enriched compound of claim 16 , wherein the compound is selected from compounds 8-14 of Table 2.

19 . A pharmaceutical composition, comprising: a pharmaceutically acceptable carrier and a therapeutically effective amount of a compound of claim 1 or a pharmaceutically acceptable salt form thereof.

20 . A method for treating a disease selected from metastatic and/or locally advanced breast cancer comprising: administering, to a patient in need thereof, a therapeutically effective amount of a compound of claim 1 or a pharmaceutically acceptable salt form thereof.