Radiohalogenated agents for in situ immune modulated cancer vaccination

1. A method of treating a metastatic cancer in a subject, wherein the metastatic cancer comprises a primary malignant solid tumor and one or more metastatic tumors capable of causing concomitant immune tolerance, the method comprising the steps of:

(a) administering to the subject an immunomodulatory dose of a radiohalogenated compound that is differentially taken up by and retained within malignant solid tumor tissue and comprises a metaiodobenzylguanidine (MIBG), wherein the iodine atom in the MIBG is a radioactive iodine isotope, or a phospholipid compound having the formula:

or a salt thereof, wherein:

R 1 comprises a radioactive halogen isotope;

a is 0 or 1;

n is an integer from 12 to 30;

m is 0 or 1;

Y is selected from the group consisting of —H, —OH, —COOH, —COOX, —OX, and —OCOX, wherein X is an alkyl or an arylalkyl; and

R 2 is selected from the group consisting of —N + H 3 , —N + H 2 Z, —N + HZ 2 , and —N + Z 3 , wherein each Z is independently an alkyl or an aryl; and

(b) performing in situ tumor vaccination in the subject at the primary malignant solid tumor using one or more treatments capable of stimulating specific immune cells within the tumor microenvironment, wherein the one or more treatments capable of stimulating specific immune cells within the tumor microenvironment comprise contacting the primary malignant solid tumor with a composition comprising one or more agents capable of stimulating specific immune cells within the tumor microenvironment;

whereby the concomitant immune tolerance caused by the metastatic tumors is prevented and the metastatic cancer is treated in the subject.

2. The method of claim 1 , wherein step (b) of performing in situ tumor vaccination in the subject further comprises treating the primary malignant solid tumor with external beam radiation therapy (xRT).

3. The method of claim 1 , wherein the immunomodulatory dose of the radiohalogenated compound delivers a radiation dose of from 2 Gy to 8 Gy to the metastatic tumors.

4. The method of claim 1 , wherein the one or more agents capable of stimulating specific immune cells within the tumor microenvironment are selected from the group consisting of an immunostimulatory mAb, a pattern recognition receptor agonist, an immunostimulatory cytokine, an immune stimulatory nanoparticle, an oncolytic virus, and combinations thereof.

5. The method of claim 4 , wherein the immunostimulatory mAb is selected from the group consisting of an anti-GD2 antibody, an anti-CTLA-4 antibody, an anti-CD137 antibody, an anti-CD134 antibody, an anti-PD-I antibody, an anti-KIR antibody, an anti-LAG-3 antibody, an anti-PD-LI antibody, an anti-CD40 antibody, and combinations thereof.

6. The method of claim 4 , wherein the immunostimulatory mAb is an antibody to a tumor-specific antigen.

7. The method of claim 5 , wherein the immunostimulatory mAb is an anti-GD2 antibody.

8. The method of claim 7 , wherein the composition comprising one or more agents capable of stimulating specific immune cells within the tumor microenvironment further comprises interleukin-2 (IL-2).

9. The method of claim 1 , wherein the composition further comprises IL-2.

10. The method of claim 4 , wherein the immunostimulatory cytokine is IL-2, interleukin-15 (IL-15), interleukin-21 (IL-21) interleukin-12 (IL-12), or an interferon.

11. The method of claim 4 , wherein the pattern recognition receptor agonist is an agonist of a toll-like receptor (TLR).

12. The method of claim 1 , wherein the radioactive iodine isotope is selected from the group consisting of 123 I, 124 I, 125 I, and 131 I.

13. The method of claim 1 , wherein the radioactive halogen isotope is selected from the group consisting of 123 I, 124 I, 125 I, 131 I, and 211 At.

14. The method of claim 13 , wherein a is 1, m is 0, n is 18, and R 2 is —N + H 3 .

15. The method of claim 14 , wherein the radiohalogenated compound is [ 123 I]—NM404, [ 124 I]—NM404, [ 125 I]—NM404 or [ 131 I]—NM404.

16. The method of claim 1 , wherein the radiohalogenated compound is administered intravenously.

17. The method of claim 1 , wherein the metastatic cancer that is treated is selected from the group consisting of melanoma, neuroblastoma, lung cancer, adrenal cancer, colon cancer, colorectal cancer, ovarian cancer, prostate cancer, liver cancer, subcutaneous cancer, squamous cell cancer of the skin or head and neck, intestinal cancer, retinoblastoma, cervical cancer, glioma, breast cancer, pancreatic cancer, soft tissue sarcomas, Ewings sarcoma, rhabdomyosarcoma, osteosarcoma, retinoblastoma, Wilms' tumor, and pediatric brain tumors.

18. The method of claim 1 , wherein the step of contacting the primary malignant solid tumor with the composition is performed by intratumorally injecting the composition into the primary malignant solid tumor.