Phase 1/2 Study of Intravenous Injection of STX-003 in Advanced Solid Tumors as Monotherapy or in Combination With Pembrolizumab

NCT07751042 | Recruiting Phase 1 FDA Drug

• 1 other identifier: STX-003-01
• Study Type: interventional
• Target: 220
• Locations: 1 country
• Sites: 2

Brief Summary

Phase 1/2, Open-label, Multi-center, First-in-human Study of the Safety, Tolerability, Pharmacokinetics, Pharmacodynamics and Anti-tumor Activity of STX-003 Delivered by Intravenous Injection in Patients with Advanced Solid Tumors as a Monotherapy or in Combination with Pembrolizumab.

Conditions

Advanced Solid Tumor

Keywords

Intravenous; Non Small Cell Lung Cancer; Melanoma; Advanced Solid Tumors; mRNA

Outcome Measures

Primary Outcomes (2)

• Incidence of TEAEs, SAEs, and DLTs

  From time of informed consent until 30 days after the last dose of investigational product.

• Occurrence of changes from baseline in patients' clinical safety laboratory values and vital signs to assess the safety and tolerability of STX-003.

  Collection and analysis of changes in data from baseline of patients' safety laboratory values (chemistry, hematology, coagulation, complement (Bb \& C3a), urinalysis, and lipids). Vital signs will include Temperature: (degrees Fahrenheit) Pulse: (beats per minute) Respiratory rate: (breaths per minute) Blood pressure: (systolic and diastolic each reported in mmHg) Oxygen saturation by pulse oximetry: (percentage (SpO2, %))

  From Day 1 until 30 days after last dose of STX-003

Secondary Outcomes (6)

• Assessment of PK and PD in patients dosed with STX-003

  Day 1,2,3,4,8,15,22,23,24,25,29,36, 43,44,51,58

• Number and nature of preliminary antitumor activity of STX-003 as monotherapy and in combination with Pembrolizumab.

  From time of informed consent until 30 days after the last dose of investigational product.

• Assessment of Tumor infiltrating lymphocytes

  From time if informed consent until 30 days after the last dose of investigational product (STX-003)

• Objective Response Rate (ORR) in patients with advanced solid tumors.

  From time of informed consent until 30 days after the last dose of investigational product.

• Assessment of PK and PD in patients dosed with STX-003

  Day 1,2,3,4,8,15,22,23,24,25,29,36, 43,44,51,58

Study Arms (4)

Phase 1 Monotherapy

EXPERIMENTAL

STX-003 administered intravenously, at ascending doses across sequential cohorts, once per cycle for up to 35 cycles (approximately 24 months).

Biological: STX-003

Phase 1 Combination (STX-003 with Pembrolizumab)

EXPERIMENTAL

STX-003 administered intravenously, at ascending doses across sequential cohorts, once per cycle in combination with pembrolizumab for up to 35 cycles (approximately 24 months).

Biological: STX-003; Biological: KEYTRUDA®

Phase 2 Monotherapy (STX-003)

EXPERIMENTAL

STX-003 administered intravenously, at 4 planned dose expansion cohorts in patients with advanced cancers with high unmet need, once per cycle for up to 35 cycles (approximately 24 months).

Biological: STX-003

Phase 2 Combination (STX-003 with Pembrolizumab)

EXPERIMENTAL

STX-003 administered intravenously, at 4 planned dose expansion cohorts in patients with advanced cancers with high unmet need, once per cycle for up to 35 cycles (approximately 24 months).

Biological: STX-003; Biological: KEYTRUDA®

Interventions

STX-003 BIOLOGICAL

STX-003 is a LNP formulated self-replicating mRNA encoding the therapeutic payload human IL-12 (hIL-12) with miRNA target sites to sense specific endogenous miRs.

Phase 1 Combination (STX-003 with Pembrolizumab); Phase 1 Monotherapy; Phase 2 Combination (STX-003 with Pembrolizumab); Phase 2 Monotherapy (STX-003)

KEYTRUDA® BIOLOGICAL

Pembrolizumab (Keytruda USPI 2026) is a marketed PD-1 blocking humanized monoclonal IgG4 kappa antibody.

Phase 1 Combination (STX-003 with Pembrolizumab); Phase 2 Combination (STX-003 with Pembrolizumab)

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Mentally competent and able to understand and sign the ICF.
• Tumor type for which there is an FDA-approved anti-PD-1/L1 antibody therapy, specifically including biomarker labeled subsets (i.e. PD-L1+) as well as anatomical subsets in some disease (cutaneous melanoma is eligible whereas acral, mucosal and uveal are not; Phase 1) and advanced cutaneous melanoma or PD-L1+ NSCLC.
• Histologically or cytologically documented, locally advanced, or metastatic solid tumor.
• At least one measurable lesion per RECIST v1.1 criteria.
• The patient lacks a curative therapy or has progressive disease despite, or refused, standard therapy.
• ECOG performance status of 0 or 1.
• Life expectancy of ≥ 12 weeks per the Investigator.
• ≥ 18 years of age at the time of informed consent.
• Body weight ≥ 40 kg.
• WOCBP and males with female partners of child-bearing potential must agree to use adequate birth control throughout their participation and for 3 months following the last dose of STX-003.
• Willing and able to comply with protocol required assessments.
• Hematology:
• ANC ≥ 1,000 cells/mm3.
• Platelet count ≥ 75,000 cells/mm3.
• Hemoglobin ≥ 8.0 g/dL.

You may not qualify if:

• Medical Conditions
• History of primary immune deficiency.
• History of clinically significant autoimmune disease that has required intervention in the last 6 months. Consultation with the MM may inform the discussion of whether autoimmune disease is clinically significant.
• History of Grade 3 or higher IRAEs that has not resolved to Grade ≤ 1 at the time of enrollment. Exceptions include endocrine disorders that are well-managed with stable physiological hormone replacement and Grade 3 immune-related rash. Patients meeting this criterion may be considered for enrollment following approval by the MM.
• History of solid organ transplant and taking immunosuppressive medications.
• Medical history of an arterial thrombotic event, stroke, or transient ischemic attack within the past 6 months.
• Medical history of symptomatic congestive heart failure (New York Heart Association classes II-IV) or a cardiac arrhythmia that required treatment within the past 6 months.
• Medical history of myocardial infarction or unstable angina within 6 months before C1D1.
• Evidence of active infection requiring IV antibiotics within 7 days prior to C1D1.
• Active uncontrolled bleeding, or a bleeding diathesis within 7 days prior to C1D1.
• Serious or non-healing wound, fistula, skin ulcer, or non-healing bone fracture within 7 days prior to C1D1.
• Known HIV infection, active hepatitis B infection, or hepatitis C infection:
• Virology evaluation should be conducted at Screening to include serum HIV antibody, HBc antibody, HBsAg antigen, and HCV antibody. Patients with a positive antibody evaluation for HCV and/or HBc should undergo evaluation to measure HCV RNA or HBV DNA, respectively.
• Untreated CNS tumor, epidural tumor or metastasis, or brain metastasis. Patients with any primary CNS malignancy including glioma and current, active, or progressing CNS malignancy, including carcinomatosis meningitis, are excluded.
• Patients with treated brain metastases are eligible if there is no evidence of progression for at least 4 weeks after CNS-directed treatment, as ascertained by clinical examination and brain imaging (MRI or CT scan) during the Screening period and are off systemic steroids (for at least 2 weeks prior to first dose).

Sponsors & Collaborators

• Strand Therapeutics Inc.: lead

Study Sites (2)

HonorHealth Research Institute

Scottsdale, Arizona, 85258, United States

RECRUITING

Sarah Cannon Research Institute

Nashville, Tennessee, 37203, United States

RECRUITING

MeSH Terms

Conditions

Carcinoma, Non-Small-Cell Lung; Melanoma

Interventions

pembrolizumab

Condition Hierarchy (Ancestors)

Carcinoma, Bronchogenic; Bronchial Neoplasms; Lung Neoplasms; Respiratory Tract Neoplasms; Thoracic Neoplasms; Neoplasms by Site; Neoplasms; Lung Diseases; Respiratory Tract Diseases; Neuroendocrine Tumors; Neuroectodermal Tumors; Neoplasms, Germ Cell and Embryonal; Neoplasms by Histologic Type; Neoplasms, Nerve Tissue; Nevi and Melanomas; Skin Neoplasms; Skin Diseases; Skin and Connective Tissue Diseases

Central Study Contacts

Jason Luke, MD, Chief Medical Officer

CONTACT

617-993-9271; stx-003-study@strandtx.com

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 6, 2026
• First Posted: August 6, 2026
• Study Start: June 30, 2026
• Primary Completion (Estimated): July 17, 2030
• Study Completion (Estimated): November 15, 2030
• Last Updated: August 6, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will not share

Locations

US (2)