Company: SHPH
Filing Date: 2025-02-27
Form Type: 424B3
Source: 0001493152-25-008476
Chunk: 16

Company: Shuttle Pharmaceuticals Holdings, Inc.
Filing Date: 2025-02-27
Form: 424B3
Chunk 16
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 delivery platform which uses HDAC inhibitors, designed to target cancer cells, while protecting healthy tissue.

HDACs are a class of enzymes that regulate gene expression through chemical modification of histones and non-histone proteins. Increased HDAC activity leads to a more condensed chromatin (which is a protein complex consisting of DNA and other proteins), decreased gene expression and loss of key gene products, including tumor suppressor gene function. Inhibition of HDAC activity leads to a more open chromatin and increased expression of the key gene products. This chromatin modification underlies the epigenetic cellular regulatory system and is an area of intense investigation.

Our research and development efforts to date have focused on the discovery of novel, dual functional molecules for potential use in cancer treatment as radiation sensitizers of cancers, protectors of normal tissues, and activators of the immune responses to antigens expressed by irradiated cancer cells. To date, we have produced three candidate molecules:

| ● | SP-1-161,                                                                                                                            
 a candidate lead of compounds demonstrating activation of the “ATM” gene product (mutated in Ataxia-Telangiectasia).                 
 Ataxia-Telangiectasia is a human genetic disease characterized by neurological, immunological and radiobiological clinical features. |
| ● | SP-2-225,                                                                                                                            
 a candidate lead of compounds demonstrating Class II (HDAC6) selective inhibition. HDAC6 is a molecule integral to the presentation  
 of antigens by macrophages to T-lymphocytes.                                                                                         |
| ● | SP-1-303                                                                                                                             
 is a candidate Class I HDAC inhibitor with preferential efficacy against ER positive cancers.                                        |

SP-1-161- A Dual Functional Agent

SP-1-161 is an HDAC inhibitor of the hydroxamate chemical class of compounds and an ATM activator of the indole chemical class. HDACs modify histones and non-histone proteins, which are key components of the chromatin structure, gene expression regulation, and cell growth. HDAC inhibitors inhibit cell proliferation, angiogenesis and immunity. Eighteen human HDACs have been identified, subdivided into four classes based on sequence and functional homology. In cancer cells, HDAC activity silences tumor suppressor genes important for cell growth regulation and to chromosomal instability. Abnormal HDAC activity is also associated with tumor cell growth, invasion, metastasis and resistance to therapy. Therefore, inhibitors of HDACs have emerged as anti-c