Company: SHPH
Filing Date: 2025-01-15
Form Type: S-1
Source: 0001493152-25-002253
Chunk: 92

Company: Shuttle Pharmaceuticals Holdings, Inc.
Filing Date: 2025-01-15
Form: S-1
Chunk 92
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ACs 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-cancer agents for cancer therapy. Vorinostat and romidepsin have been approved by the FDA for treatment of patients with relapsed or refractory T-cell lymphomas. In addition, panobinostat received FDA approval for treatment of recurrent multiple myeloma in combination with bortezomib and dexamethasone.

In preclinical studies, SP-1-161 inhibited the activity of pan-HDACs and activated the ATM gene product. ATM is a critical protein for the activation of the cell stress response for cellular recovery from radiation exposure in normal cells, but not in cancer cells. ATM activates the P53 protein, referred to as the “guardian of the genome,” and serves as a tumor suppressor critical for normal cell function and activation of programmed cell death in cancer cells.

In preclinical studies, SP-1-161 protected normal breast epithelial cells (184A1) following exposure to ionizing radiation while increasing sensitivity of breast cancer cells (MCF7). SP-1-161 provides this dual function in a single molecule and this molecule is differentiated from other HDAC inhibitors by treatment of cancers while protecting normal cells. ( SeeGrindrod S, Brown M, Jung M. “Development of dual Function Small Molecules 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