Silanol based therapeutic payloads

1. A method of delivering a therapeutically effective amount of a silanol drug moiety to a patient in need thereof, comprising administering to the patient a drug conjugate represented by:

wherein

Lig is a targeting moiety;

L 1 is a linker moiety;

A is an adaptor moiety or a bond;

Y 2 is represented by: L 22 or BOL 22 -SL-, wherein BO is a bond or is a fused biorthogonal linker moiety, L 22 is a second linker moiety, and SL is an optional catalytic moiety;

n is 1, 2, 3, 4, 5, 6 or 7;

Y is a divalent spacer moiety; and

D, for each occurrence, is a drug moiety that effects a target cell or tissue.

2. The method of claim 1 , wherein the drug conjugate releases the silanol drug moiety in a pH dependent fashion.

3. The method of claim 1 , wherein the silanol drug moiety is represented by:

4. The method of claim 1 , wherein SL is chosen to release the silanol drug moiety from the conjugate at pH less than about 7 at 25° C. or 37° C.

5. The method of claim 1 , wherein A selected from the group consisting of a bond,

6. The method of claim 1 , wherein BO is selected from the group consisting of:

and —S—.

7. The method of claim 1 , wherein BO is:

8. The method of claim 1 , wherein L 22 is selected from the group consisting of: —(CH 2 —CH 2 —O) s —, —(OCH 2 —CH 2 ) s —, —(CH 2 —CH 2 —O) s —(CH 2 ) i —, —(CH 2 ) i —(OCH 2 —CH 2 ) s —, and C 1-6 alkylene; wherein s is 0 to 10 for each occurrence; and i is 1, 2, or 3.

9. The method of claim 1 , wherein SL is selected from the group consisting of —NR Y —C(O)—(CH 2 ) j -phenyl-(CH 2 ) q — (wherein R Y is hydrogen or C 1-3 alkyl; j is 0, 1, 2, 3 or 4; and q is 0, 1 or 2); 5-6 membered heteroaryl-S—(CH 2 ) p — (wherein p is 0, 1, 2, or 3), a bond, and —NR Y —C(O)—C 1-4 alkylene (wherein R Y is hydrogen or C 1-3 alkyl).

10. The method of claim 1 , wherein SL is selected from the group consisting of:

11. The method of claim 1 , wherein SL is:

12. The method of claim 1 , wherein Y is selected from the group consisting of a bond, C 1-4 alkylene, C 1-4 alkylene-NR Y —, C 1-4 alkylene-C(O)—, and C 1-4 alkylene-C(O)—NR Y —, wherein R Y is hydrogen or C 1-3 alkyl.

13. The method of claim 1 , wherein Y is selected from the group consisting of: a bond,

14. The method of claim 1 , wherein L 1 is C 1-30 alkylene; wherein one, two, three, four, five, six, seven or eight methylene units of L 1 are optionally and independently replaced by a substituent each selected from the group consisting of phenyl, heteroaryl, —N(R1 Y )—, —C(O)N(R 1 )—, —N(R 1 )C(O))—, —O—, (—O—CH 2 —CH 2 ) s —, and (CH 2 —CH 2 —O) s —, wherein s is an integer from 3-10; and R 1Y is independently selected for each occurrence from the group consisting of hydrogen and C 1-3 alkyl.

15. The method of claim 1 , wherein D is selected from the group consisting of a vinca alkaloid, an auristatin, maytansine, a pyrrolobenzodiazepine dimer, a camptothecin, SN38, a PARP inhibitor, salinomycin, a kinase inhibitor, siRNA, and a nuclear hormone regulator.

16. The method of claim 1 , wherein the drug conjugate is represented by: