Company: SHPH
Filing Date: 2025-01-24
Form Type: 424B3
Source: 0001493152-25-003508
Chunk: 91

Company: Shuttle Pharmaceuticals Holdings, Inc.
Filing Date: 2025-01-24
Form: 424B3
Chunk 91
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 as Therapeutic Agents for Cancer Research,” Poster presentation #A178, American Association of Cancer Research Oct 2017).

SP-2-225

SP-2-225 is a selective HDAC inhibitor that affects histone deacetylase (HDAC6) and is a member of the class IIb HDAC family. Class II HDACs play important roles in cancer motility, invasion, neurological diseases, and immune checkpoint. HDAC6 inhibition has been most extensively studied for its role in the treatment of hematological cancers. HDAC6 is unique among HDAC enzymes in having two active catalytic domains and a unique physiological function. In addition to the modification of histones, HDAC6 targets specific substrates including α-tubulin and HSP90, and are involved in protein trafficking and degradation, cell shape and migration. Selective HDAC6 inhibitors are an emerging class of pharmaceuticals due to the involvement of HDAC6 in pathways related to neurodegenerative diseases, cancer and immunology. Specifically, its potential to affect regulation of the immune system and enhance the immune response in cancer is of great interest. With the introduction of check-point inhibitors, CAR-T therapies and personalized medicine in cancer, regulation of the immune response to this therapy is of significant clinical and commercial interest. (See Noonepalle SKR, Grindrod S, Aghdam N, Li X, Gracia-Hernandez M, Zevallos-Delgado C, Jung M, Villagra A, Dritschilo A. Radiotherapy-induced Immune Response Enhanced by Selective HDAC6 Inhibition. Mol Cancer Ther. 2023 Dec 1;22(12):1376-1389. doi: 10.1158/1535-7163.)

Selective inhibition of HCAC6 reduces dose limiting side effects associated with non-selective HDAC inhibitors. Selective HDAC6 inhibitors may be combined with other cytotoxic agents. Shuttle’s discovery of selective HDAC inhibitors has yielded several HDAC6 selective candidate molecules including SP-2-225. HDAC6 inhibitors are under investigation for roles in the treatment of diseases such as multiple myeloma.

SP-1-303- Target Indication: Breast Cancer

Histone deacetylase inhibitors sensitize cancers to the effects of radiation, protect normal tissues from radiation injury and activate the immune system. SP-1-303 is a selective Class I HDAC inhibitor that inhibits HDAC1, 3 and 6 and has