Company: SHPH
Filing Date: 2025-01-15
Form Type: S-1
Source: 0001493152-25-002253
Chunk: 88

Company: Shuttle Pharmaceuticals Holdings, Inc.
Filing Date: 2025-01-15
Form: S-1
Chunk 88
---
insella TJ, Loparo KA. Probabilistic modeling of DNA mismatch repair effects on cell cycle dynamics and iododeoxyuridine-DNA incorporation. Cancer Res. Nov 15 2007; 67(22):10993-11000).

Most of the clinical efficacy data were obtained from NIH supported studies performed with IUdR, the active metabolite of Ropidoxuridine. However, IUdR requires constant infusion over six weeks of therapy which creates a significant compliance issue for patients. Ropidoxuridine can be given as a capsule for oral administration, resulting in greater ease of medication delivery and potentially improved compliance and fewer complications.

Over the last 20 years, there has been renewed interest in these halogenated TdR analogs as experimental radiation sensitizers in selected cancer patient groups. These analogs are rapidly metabolized in both rodents and humans, principally with cleavage of deoxyribose and subsequent dehalogenation by hepatic and extrahepatic metabolism, when given as a bolus infusion with a plasma half-life of <5 min. Consequently, prolonged continuous or repeated intermittent drug infusions over several weeks before and during irradiation are necessary, based on in vivo human tumor kinetics, to maximize the proportion of tumor cells that incorporate these analogs into DNA during the S phase of the cell cycle. ( SeeFowler JF, Kinsella TJ. The Limiting Radiosensitization of Tumors by S-phase Sensitizers. Br J Cancer. 1996;74 (Suppl)(27):294-296). Phase I and Phase II trials using prolonged continuous or repeated intermittent intravenous infusions of BUdR or IUdR before and during radiation therapy (RT) have focused principally on patients with high-grade brain tumors. These clinically radiation resistant tumors can have a rapid proliferation rate (potential tumor doubling times of 5–15 days) and are surrounded by non-proliferating normal brain tissues that show little to no DNA incorporation of the TdR analogs. As such, high-grade brain tumors are ideal targets for this approach to radiation sensitization. In Phase I/Phase II clinical trials, prolonged survival outcomes were observed compared to RT alone in patients with anaplastic astrocytomas and in patients with glioblastoma multiforme IUdR continuous IV infusion (1000 mg/m 2/ day/ 14 days), Total 39 patients (F. Sullivan, et al. Int J Radiat