Investigating the safety and efficacy of FB849 for advanced solid tumors

A Phase I/II, Open-label Study to Investigate the Safety, Tolerability, Pharmacokinetics, and Preliminary Efficacy of FB849 Administered in Subjects With Advanced Solid Tumors Alone and in Combination With Pembrolizumab

PHASE1; PHASE2 · 1ST Biotherapeutics, Inc. · NCT05761223

This study is testing a new treatment called FB849, alone and with another drug, to see if it can help people with advanced solid tumors who don’t have other treatment options.

Quick facts

PhasePHASE1; PHASE2
Study typeInterventional
Enrollment151 (estimated)
Ages18 Years and up
SexAll
Sponsor1ST Biotherapeutics, Inc. (industry)
Drugs / interventionschemotherapy, pembrolizumab
Locations5 sites (Cleveland, Ohio and 4 other locations)
Trial IDNCT05761223 on ClinicalTrials.gov

What this trial studies

This is a first-in-human, multicenter, open-label Phase I/II study designed to evaluate the safety, tolerability, pharmacokinetics, and preliminary efficacy of FB849, both alone and in combination with pembrolizumab, in patients with advanced solid tumors who lack standard treatment options. The study consists of four parts, including a dose-escalation phase to determine the maximum tolerated dose and a dose-expansion phase to assess safety and anti-tumor activity. An adaptive Bayesian optimal interval design will be utilized to allow for flexible dose adjustments based on patient responses. The study aims to provide critical insights into the therapeutic potential of FB849 in this challenging patient population.

Who should consider this trial

Good fit: Ideal candidates include adults aged 18 and older with measurable advanced solid tumors and an ECOG performance status of 0 or 1.

Not a fit: Patients with known allergies to the study treatment components or those with additional malignancies requiring active treatment may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could offer a new treatment option for patients with advanced solid tumors who currently have no effective therapies available.

How similar studies have performed: Other studies have shown promise with similar approaches, but this specific combination and methodology may provide novel insights.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Subject should understand, sign, and date the written ICF prior to screening.
* Male or female aged 18 years or older.
* Subjects must have at least 1 measurable target lesion according to RECIST version 1.1.
* Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1
* Life expectancy ≥ 3 months in the opinion of the investigator.
* Adequate organ function and bone marrow function as indicated by the following screening assessments performed within 14 days prior to the first dose of study treatment

Exclusion Criteria:

* Known allergy or hypersensitivity to any component of the study treatment.
* Has a known additional malignancy that is progressing or has required active treatment.
* Has abnormal or inadequately controlled endocrine function.
* Inability to take oral medication or significant nausea and vomiting, malabsorption, external biliary shunt, or significant bowel resection that would preclude adequate absorption of oral medication.
* Previous anti-cancer therapy, including chemotherapy (chemotherapy with nitrosourea or mitomycin should be at least 6 weeks prior to initiation of study treatment), radiotherapy, molecular targeted therapy, or other investigational drugs received ≤ 4 weeks; endocrine therapy ≤ 2 weeks or ≤ 5-half-lives (whichever is shorter) prior to initiation of study treatment.

Where this trial is running

Cleveland, Ohio and 4 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Advanced Solid Tumor

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.