Study of STP938 (Dencatistat) in Advanced Solid Tumours

An Open-Label, Phase 1 Study to Evaluate Safety, Tolerability and Pharmacokinetics of the CTPS1 Inhibitor STP938 in Adult Subjects With Advanced Solid Tumors, With a Safety Expansion in Advanced CTPS2 Null Ovarian Cancer

The Phase 1a part of the study is a dose escalation of STP938 as a monotherapy.

The Phase 1b part of the study is a safety expansion cohort of STP938 as a monotherapy.

Study Overview

• Status: Recruiting
• Conditions: Solid Tumor
• Intervention / Treatment: Drug: STP938

• Study Type: Interventional
• Enrollment (Estimated): 70
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Maureen Higgins; Phone Number: +33 1 86 26 43 56; Email: STP938-201@step-ph.com
• Study Contact Backup: Name: Duc Tran; Phone Number: +33 1 86 26 43 56; Email: STP938-201@step-ph.com

Study Locations

• France
  • Paris
    • Villejuif, Paris, France, 94805
      • Recruiting
      • Institut Gustave Roussy
• United Kingdom
  • London, United Kingdom
    • Recruiting
    • University College London
  • Manchester, United Kingdom, M20 4BX
    • Recruiting
    • The Christie
  • Glasgow
    • Glasgow, Glasgow, United Kingdom, G12 8QQ
      • Recruiting
      • The Beatson Institute for Cancer Research
• United States
  • Florida
    • St. Petersburg, Florida, United States, 33709
      • Recruiting
      • Comprehensive Hematology Oncology, LLC
  • Texas
    • Dallas, Texas, United States, 75251
      • Recruiting
      • Mary Crowley Cancer Research Center
    • San Antonio, Texas, United States, 78292
      • Recruiting
      • NEXT Oncology

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Main Inclusion Criteria:

• Signed and dated informed consent, and able to comply with the study procedures and any locally required authorization.
• Male or female aged ≥ 18 years.
• Advanced disease not curable by available therapies and requires systemic therapy.
• Histologically confirmed diagnosis of eligible cancer type.
• Must have tumor tissue available for biomarker testing.
• Measurable disease (Part 1) and measurable disease per RECIST (Part2)
• Eastern Cooperative Oncology Group (ECOG) performance status ≤2.
• Life expectancy > 3 months as assessed by the Investigator.
• Adequate organ function (bone marrow, hepatic, renal function and coagulation).
• All toxicities (except alopecia) from prior cancer treatments or procedures must have resolved to ≤Grade 1 or returned to baseline levels prior to enrollment.

Main Exclusion Criteria:

• Pregnant or breastfeeding females and women of childbearing potential or males unwilling to comply with contraception requirements.
• Known active or symptomatic CNS metastases, carcinomatous meningitis, leptomeningeal disease or a history of spinal cord compression
• Active malignancy within 2 years of study enrollment
• Prior radiation within 2 weeks of start of therapy.
• Systemic cancer treatments, monoclonal antibody-directed therapies, other investigational agents within 4 weeks before enrollment, or <5 half-lives since completion of previous investigational therapy, whichever is shorter.
• Uncontrolled intercurrent illness.
• Immunocompromised subjects with increased risk of opportunistic infections or history of opportunistic infection in the last 12 months.
• Known active or chronic hepatitis B or active hepatitis C virus (HCV) infection.
• Subjects with corrected QT interval >470 msec based on averaged triplicate electrocardiogram (ECG) readings at the Screening Visit using the QT interval corrected for heart rate using Fridericia's method (QTcF).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Sequential Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Phase 1a (Part 1, Dose Escalation); Up to 5 dose levels with STP938 administered as oral monotherapy	Drug: STP938; Small molecule
Experimental: Phase 1b (Part 2, Safety Expansion); Further evaluation of STP938 administered as oral monotherapy at the RP2D	Drug: STP938; Small molecule

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Safety and Tolerability	Incidence of dose limiting toxicities (DLTs), serious adverse events (SAEs), treatment-emergent adverse events (TEAEs)	Through study completion, an average of 6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Area under the curve (AUC) of STP938	Pharmacokinetic parameter from plasma STP938 levels	9 days
Maximum plasma concentration (Cmax)	Pharmacokinetic parameter from plasma STP938 levels	9 Days
Time to reach maximum concentration (TMax)	Pharmacokinetic parameter from plasma STP938 levels	9 Days
Evaluation of preliminary clinical activity of STP938	Evaluation of ORR using standard response criteria	Through study completion, an average of 6 months
Evaluation of best overall response of STP938	Evaluation of best overall response (Complete response [CR], Partial response [PR], Stable disease [SD], Progression of disease [PD], Not evaluable, Not applicable) using standard response criteria	Through study completion, an average of 6 months
Evaluation of Duration of Response	Duration of response (DoR) is defined as the time, in days, from the date measurement criteria that are first met for CR or PR (whichever is first recorded) to the first date that relapse, progressive disease or death, whichever occurs first	Through study completion, an average of 6 months
Evaluation of Progression Free Survival	Progression-free survival (PFS) is defined as the time from first STP938 dose to the date of disease progression or death, whichever occurs first	Through study completion, an average of 6 months
Change in serum CA125 (ovarian cancer only)	Evaluation of CA125 using standard response criteria	Through study completion, an average of 6 months

Collaborators and Investigators

• Sponsor: Step Pharma, SAS
• Investigators: Study Director: Maureen Higgins, Step Pharma

Study record dates

Study Major Dates

• Study Start (Actual): August 2, 2024
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): May 1, 2027

Study Registration Dates

• First Submitted: February 29, 2024
• First Submitted That Met QC Criteria: February 29, 2024
• First Posted (Actual): March 7, 2024

Study Record Updates

• Last Update Posted (Actual): June 16, 2026
• Last Update Submitted That Met QC Criteria: June 13, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neoplasms
• Other Study ID Numbers: STP938-201

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No