---
schema_version: "secwatch.filing_event.v1"
accession: "0001493152-23-016290"
form_type: "8-K"
ticker: "SHPH"
cik: "0001757499"
company_name: "Shuttle Pharmaceuticals Holdings, Inc."
filed_at: "2023-05-11T23:59:59+00:00"
generated_at: "2026-06-15T04:26:45.356459+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.65
calibrated_materiality_score: 0.65
confidence: "high"
source: SEC EDGAR
---

# Shuttle Pharma amends Alto warrant, secures $1.5M cash collateral, and receives new patent

## Summary
- Amended Alto warrant to remove anti-dilution adjustment; obtained shareholder approval for up to $10M additional convertible notes and warrants.
- Alto releases $1.5M cash collateral: $1M immediately, $500K upon filing Schedule 14C.
- U.S. Patent No. 11,654,157 approved for cancer therapy combining halogenated thymidines, thymidine phosphorylase inhibitors, and radiation; issuance May 23, 2023.

## SEC filing metadata
- accession: 0001493152-23-016290
- form_type: 8-K
- ticker: SHPH
- cik: 0001757499
- company_name: Shuttle Pharmaceuticals Holdings, Inc.
- filed_at: 2023-05-11T23:59:59+00:00
- event_type: other_material
- sentiment: neutral
- materiality_score: 0.65
- calibrated_materiality_score: 0.65
- confidence: high
- sec_items: 1.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1757499/000149315223016290/0001493152-23-016290-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1757499/000149315223016290/form8-k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001493152-23-016290
- JSON: https://secwatch.observer/filing/0001493152-23-016290.json
- Plain text: https://secwatch.observer/filing/0001493152-23-016290.txt

## Key facts
- Material Agreements
  Shuttle Pharmaceuticals Holdings, Inc. amended Amendment Agreement to the Securities Purchase Agreement dated January 11, 2023 with Alto Opportunity Master Fund, SPC – Segregated Master Portfolio B valued at Amended the Transaction Documents to remove a provision in the Alto Warrant, stipulated issuance of (effective 2023-05-10).
  - Action: amendment
  - Agreement: equity purchase
  - Counterparty: Alto Opportunity Master Fund, SPC – Segregated Master Portfolio B
  - Value: Amended the Transaction Documents to remove a provision in the Alto Warrant, stipulated issuance of
  - Effective: 2023-05-10
  source text: On May 10, 2023, Shuttle Pharmaceuticals Holdings, Inc., a Delaware corporation (the “Company”), entered into an amendment agreement (the “Amendment Agreement”) to the Securities Purchase Agreement, originally dated January 11, 2023 (the “SPA”), between the Company, Alto Opportunity Master Fund, SPC – Segregated Master Portfolio B (“Alto”), in its capacity as the registered holder of a $4.3 million convertible note (the “Alto Note”) and warrant to purchase 1,018,079 shares of common stock (the “Alto Warrant”) issued by the Company, and the Company’s wholly owned subsidiary, Shuttle Pharmaceuticals, Inc., as guarantor (“Shuttle Pharma”). (The Alto Note, Alto Warrant and the SPA are referred to herein as the “Transaction Documents”). Under the Amendment Agreement, the Company and Alto amended the Transaction Documents as follows: (i) amended and restated Section 2 of the Alto Warrant so as to remove a provision that would have potentially required an adjustment to the number of warrant s
  evidence_url: https://www.sec.gov/Archives/edgar/data/1757499/000149315223016290/0001493152-23-016290-index.htm

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.