(Note: This IPO is a unit offering. Each unit consists of one share of common stock and one warrant to buy one share of common stock. This is a NASDAQ listing.)

Founded in 2012 by faculty members of the Georgetown University Medical Center, Shuttle Pharmaceuticals is a discovery and development- stage specialty pharmaceutical company focused on improving the outcomes of cancer patients treated with radiation therapy (RT). Our mission is to improve the lives of cancer patients by developing therapies that are designed to maximize the effectiveness of RT while limiting the late effects of radiation in cancer treatment.

Our pipeline includes Ropidoxuridine, our lead clinical sensitizer drug candidate, to sensitize rapidly growing cancer cells and selective histone deacetylase (HDAC) inhibitors to sensitize cancer cells and stimulate the immune system. Our novel technologies will be tested in combinations with radiation therapies (conventional X-ray and proton radiation therapies) and in combinations with immune therapies. To date, Ropidoxuridine has completed a Phase I clinical trial. Our HDAC inhibitor platform drug candidates have been tested in preclinical models of solid tumor cancers. Ropidoxuridine and the selective HDAC6 inhibitor SP-2-225 are the clinical and preclinical candidate drug products we propose to develop using funding from this offering.

Ropidoxuridine (IPdR) is an orally available halogenated pyrimidine (5-iodo-2-pyrimidinone-2-deoxyribose) with strong cancer radiation sensitizing properties. As a prodrug that does not become an active drug until after it is metabolized, IPdR is absorbed and metabolized to IUdR by enzymes in the liver and in cancer cells. IUdR, a halogenated pyrimidine, is incorporated into DNA by rapidly growing cancer cells. Cells that incorporate IUdR into their DNA then become more sensitive to the effects of RT. The Phase I clinical trial of Ropidoxuridine and RT, supported by a National Institutes of Health (NIH) Small Business Innovation Research (SBIR) contract to Shuttle Pharma, was sub-contracted to the Brown University Oncology Group (BrUOG) at the LifeSpan/Rhode Island Hospital. This Phase I clinical trial has been completed and the results were initially reported by the sub-contractor at the 30th EORTC-NCI-AACR Symposium in November 2018 and published in the medical journal Clinical Cancer Research in 2019. A maximum tolerated dose (MTD) of 1200 mg/day for 28 days was established for use in combination with radiation therapy to achieve therapeutic blood levels of IUdR.

The reported Phase I clinical trial of Ropidoxuridine in combination with RT provides the foundation for proposed Phase II clinical trials to establish the data necessary for the U.S. Food and Drug Administration to determine efficacy in treating brain tumors, sarcomas and pancreatic cancers, diseases that offer potential for orphan designations. The FDA granted approval of our application for orphan-drug designation for IPdR for the treatment of glioblastoma. Orphan designation protects the marketing position of Ropidoxuridine for up to seven years after marketing approval is received from the FDA. This approval integrates well into the overall intellectual property strategy for Ropidoxuridine, which includes filed patent applications for “Method and Compositions for Cancer Therapies that Include Delivery of Halogenated Thymidines and Thymidine Phosphorylase Inhibitors in Combination with Radiation.”

**We believe that we are positioned to initiate Phase II clinical studies with Ropidoxuridine and RT in 2022.

**Note – From the prospectus: “We have not generated any revenue and have incurred losses in each year since our founding in December 2012. Our net loss for the year ended Dec. 31, 2021, was $1.15 million. For the three months ended March 31, 2022, our net loss was $638,830.  As of March 31, 2022, we had an accumulated deficit of $6,503,039 and received a “going concern” opinion from our independent auditors for the fiscal year ended Dec. 31, 2021.”

(Note: Shuttle Pharmaceuticals Holdings, Inc. priced its IPO – a unit deal – on Aug. 30, 2022, at $8.125 ($8.13) per unit and sold 1.23 million units (1,225,888 units) – in sync with the terms in its prospectus – to raise $9.96 million. Shuttle Pharmaceuticals trimmed its IPO’s size to 1.23 million units, down from 1.25 million units, and raised the price to $8.125 ($8.13) per unit, according to an S-1/A filing dated Aug. 25, 2022. Just two days before – on Aug. 23, 2022 – the company added Valuable Capital as a joint book-runner and reworked its IPO to 1.

(Note: Previous filing details: Shuttle Pharmaceuticals Holdings, Inc. reworked its IPO in an S-1/A filing dated Aug. 18, 2022: 1.66 million units, down from 2.5 million shares, and raised the IPO price to $6.00 per unit, up from its previous price range of $4.00 to $5.00, to raise $9.96 million. Previously, in an S-1/A filing dated July 13, 2022: Shuttle Pharmaceuticals cut the size of its IPO by 21 percent – reducing the number of shares to 2.5 million and trimming the price range to $4.00 to $5.00 – to raise $14.25 million. Its initial terms:  3.0 million shares at $4.50 to $5.00. Shuttle Pharmaceuticals Holdings, Inc. filed its S-1 (prospectus) on June 3, 2022.)