APX-343A alone or with pembrolizumab for advanced solid tumors

A Phase 1 Trial of APX-343A as Monotherapy or in Combination With Pembrolizumab to Assess the Safety, Tolerability, Pharmacokinetics, and Preliminary Efficacy in Subjects With Advanced Solid Tumors

This Phase 1 trial will test whether APX-343A by itself or combined with the immunotherapy pembrolizumab is safe and shows early benefit in adults with advanced solid tumors.

Quick facts

• Phase: Phase 1
• Study type: Interventional
• Enrollment: 110 (estimated)
• Ages: 19 Years and up
• Sex: All
• Sponsor: Aptabio Therapeutics, Inc. (Indiv)
• Drugs / interventions: pembrolizumab, immunotherapy
• Locations: 3 sites (Seongnam and 2 other locations)
• Trial ID: NCT07123415 on ClinicalTrials.gov

What this trial studies

This is an open-label, Phase 1 dose-escalation trial with two parts: Part A tests APX-343A monotherapy and Part B tests APX-343A combined with pembrolizumab. The main goals are to define safety, tolerability, and pharmacokinetics, and to look for preliminary signs of anti-tumor activity using RECIST v1.1 measures. Eligible participants must be adults with histologically confirmed advanced solid tumors, ECOG 0–1, measurable disease, and provide tumor tissue or a fresh biopsy. Dosing cohorts will be escalated per protocol to identify recommended doses for further study.

Who should consider this trial

Good fit: Ideal candidates are adults (≥19 years) with histologically confirmed advanced solid tumors, ECOG performance status 0–1, measurable disease, adequate organ function, and available tumor tissue or biopsy.

Not a fit: Patients with poor performance status (ECOG >1), life expectancy under three months, uncontrolled organ dysfunction, or who cannot provide required tissue or tolerate biopsy are unlikely to benefit from this study.

Why it matters

Potential benefit: If successful, this approach could offer a new treatment option or improve responses to PD-1 immunotherapy for some patients with advanced solid tumors.

How similar studies have performed: Combining agents that target the tumor microenvironment with PD-1 inhibitors has shown early promise in other studies, but APX-343A itself is in first-in-human testing and remains unproven.

Eligibility criteria

Inclusion Criteria:

1. Male or female subjects aged ≥19 years, inclusive, at the time of informed consent.
2. Willing and able to give informed consent and to comply with the requirements of the study.
3. Histologically or cytologically confirmed advanced solid tumor.
4. Life expectancy of at least 3 months in the judgment of the investigator.
5. ECOG performance status of 0 to 1 during the screening period.
6. Measurable disease per RECIST v1.1 as assessed by the site investigator/radiology.
7. Archival tumor tissue sample or newly obtained biopsy of a tumor lesion not previously irradiated has been provided.
8. Subjects who have AEs due to previous anticancer therapies must have recovered to ≤ Grade 1 or baseline.
9. Adequate organ function as defined in the following table.
10. Subjects who are hepatitis B surface antigen positive are eligible if they have received HBV antiviral therapy for at least 4 weeks and have undetectable HBV viral load prior to the first dose of study drug.
11. Subjects with history of HCV infection are eligible if HCV viral load is undetectable at screening.
12. Male subjects must agree to use an adequate method of contraception.
13. Female subjects of childbearing potential must agree to use highly effective contraceptive methods, and to abstain from breastfeeding.

Exclusion Criteria:

1. Received any prior immunotherapy.
2. Received prior systemic anticancer therapy including investigational agents.
3. Received prior radiotherapy.
4. Received a live or live-attenuated vaccine .
5. Has received an investigational agent.
6. Diagnosis of immunodeficiency or is receiving chronic systemic steroid therapy.
7. Known additional malignancy.
8. Known active CNS metastases and/or carcinomatous meningitis.
9. Active autoimmune disease.
10. History of (noninfectious) pneumonitis/interstitial lung disease.
11. Active, uncontrolled infection requiring systemic therapy.
12. Unable to swallow study drug or disease that interfere with proper absorption of study drug.
13. Significant cardiovascular disease.
14. Cerebrovascular accident.
15. History or current evidence of any condition, therapy, laboratory abnormality, or other circumstance that might confound the results of the study or interfere with the subject's ability to cooperate with the requirements of the study.
16. History of severe hypersensitivity to pembrolizumab and/or any of its excipients.
17. History of hypersensitivity to APX-343A and/or any of its excipients.
18. History of allogeneic tissue/solid organ transplant.
19. History of HIV infection or HIV positive at screening.
20. Subjects who have not adequately recovered from major surgery or have ongoing surgical complications.

Where this trial is running

Seongnam and 2 other locations

• Seoul National University Bundang Hospital — Seongnam, South Korea (Recruiting)
• Gangnam Severance Hospital, Yonsei University Health System — Seoul, South Korea (Recruiting)
• Severance Hospital, Yonsei University Health System — Seoul, South Korea (Recruiting)

Study contacts

• Study coordinator: Clinical Center, Clinical Center

Conditions Advanced Solid Cancer; Advanced Solid Tumor; APX-343A; ICI; CAF; NOX