A Study to Assess the Safety and Tolerability of CFT8634 in Locally Advanced or Metastatic SMARCB1-Perturbed Cancers, Including Synovial Sarcoma and SMARCB1-Null Tumors

A Phase 1/2 Open-Label, Multicenter Study to Characterize the Safety and Tolerability of CFT8634 in Subjects With Locally Advanced or Metastatic SMARCB1-Perturbed Cancers, Including Synovial Sarcoma and SMARCB1-Null Tumors

This is an open-label, non-randomized, first-in-human Phase 1/2 study designed to evaluate the safety and tolerability of CFT8634 in subjects with synovial sarcoma and SMARCB1-null tumors who: have received prior systemic therapy; have relapsed/refractory tumors; have unresectable or metastatic disease; and are not candidates for available therapies known to confer clinical benefit. The study will characterize the safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary antitumor activity of CFT8634.

Study Overview

• Status: Terminated
• Conditions: Soft Tissue Sarcoma; Synovial Sarcoma
• Intervention / Treatment: Drug: CFT8634

Detailed Description

The study was intended to be Phase 1/2 trial but did not advance to Phase 2.

• Study Type: Interventional
• Enrollment (Actual): 49
• Phase: Phase 1

Contacts and Locations

Study Locations

• United States
  • California
    • Duarte, California, United States, 91010
      • City of Hope
    • Santa Monica, California, United States, 90403
      • Sarcoma Oncology Research Center
  • Colorado
    • Aurora, Colorado, United States, 80045
      • University of Colorado - Aurora Cancer Center
  • Florida
    • Jacksonville, Florida, United States, 32224
      • Mayo Clinic - Jacksonville
  • Iowa
    • Iowa City, Iowa, United States, 52242
      • University of Iowa Hospital and Clinics
  • Massachusetts
    • Boston, Massachusetts, United States, 02114
      • Massachusetts General Hospital
  • Minnesota
    • Rochester, Minnesota, United States, 55905
      • Mayo Clinic - Rochester
  • Missouri
    • Saint Louis, Missouri, United States, 63110
      • Washington University School of Medicine
  • New York
    • New York, New York, United States, 10027
      • Columbia University
    • New York, New York, United States, 10021
      • David H. Koch Center for Cancer Care at Memorial Sloan Kettering Cancer Center
  • Ohio
    • Cincinnati, Ohio, United States, 45229
      • Cincinnati Children's Hospital Medical Center
  • Texas
    • Houston, Texas, United States, 77030
      • MD Anderson Cancer Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 12 years and older (Child, Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Subject (and legal guardian where applicable) is (are) willing and able to provide signed informed consent (or assent, where applicable) and can follow protocol requirements

2. Subject has histologically or cytologically confirmed synovial sarcoma or SMARCB1-null sold tumor that is relapsed/refractory, and unresectable or metastatic; the subject must not be a candidate for available therapies that are known to confer clinical benefit

   a. Phase 1: subject must have received ≥1 prior line of systemic anticancer therapy considered to be Standard of Care per the Investigator's judgment, in the metastatic or unresectable setting b. Phase 2: i. Arm A: subject must have received only 1-2 prior lines of systemic anticancer therapy considered to be Standard of Care per the Investigator's judgment, in the metastatic or unresectable setting ii. Arm B: subject must have received ≥1 prior line of systemic anticancer therapy considered to be Standard of Care per the Investigator's judgment, in the metastatic or unresectable setting

3. Subject must be:

   • ≥18 years of age (no minimum weight),
   • ≥16 and <18 years old and weighs ≥50 kg,
   • ≥12 and <16 years of age and weighs ≥40kg,
   • or ≥16 and <18 years of age and weighs ≥40kg and <50kg
4. Subject must be able to safely swallow capsules
5. Subject must have measurable disease as defined by RECIST v1.1
6. Subject must have Eastern Cooperative Oncology Group performance status ≤2 or Lansky performance scale (LK scale) ≥ 60

7. Subject must have adequate organ function, defined as:

   1. Bone marrow function: absolute neutrophil count ≥1.0 x 109/L independent of growth factor support for ≤7 days prior to first dose of study drug for granulocyte colony-stimulating factor and ≤14 days prior to first dose of study drug for peg-filgrastim; hemoglobin ≥8 g/dL independent of transfusion support for ≤7 days prior to first dose of study drug; platelet count ≥75 x 109 /L independent of transfusion support for ≤3 days prior to first dose of study drug
   2. Coagulation: Prothrombin time (PT)/international normalized ratio (INR) <1.5x the upper limit of normal (ULN) and activated partial thromboplastin time (aPTT) <1.5x ULN (unless the subject is receiving anticoagulant therapy and INR and partial PT/aPTT are within therapeutic range of intended use of anticoagulants)
   3. Liver function: total bilirubin ≤1.5x ULN (≤3.0x ULN for subjects with Gilbert's syndrome), aminotransferase (ALT) and aspartate aminotransferase (AST) ≤3.0x ULN; except for subjects who have tumor infiltration of the liver, where ALT and AST ≤5x ULN
   4. Renal function: must have a creatinine clearance ≥60 mL/min (via Cockcroft-Gault equation, institutional standard, or measured)
   5. Cardiac function: baseline corrected QT interval using Fredericia's formula ≤470 ms (adolescents 12-17 years of age: ≤450 ms) and a left ventricular ejection fraction ≥50% evaluated via echocardiogram or multi-gated acquisition (MUGA) scan
8. Availability of archival tumor tissue sample or newly obtained core/excisional biopsy of a tumor not previously irradiated
9. A female subject may be eligible to participate if she is not pregnant or planning a pregnancy, not breastfeeding, and following protocol mediated guidance to avoid pregnancy
10. A male subject must have had a prior vasectomy and agree to use a condom during the treatment period and for at least 90 days after the last dose of study treatment
11. A male subject must refrain from donating sperm while taking CFT8634 and for 90 days post-last dose
12. A female subject must refrain from donating ova while taking CFT8634 and for 180 days after discontinuation
13. All subjects must refrain from donating blood and blood products while receiving study drug and for 30 days post-last dose

Exclusion Criteria:

1. Subject has had major surgery within 21 days prior to the planned first dose of CFT8634

   a. Minor surgery (eg, minor biopsy of extracranial site, central venous catheter placement, shunt revision) is permitted within 21 days prior to first dose of CFT8634

2. Subject has received standard of care or investigational systemic anti-neoplastic therapy within 14 days or 5 half-lives, whichever is shorter, prior to the planned first dose of CFT8634
3. Subject has received radiation therapy within 14 days prior to the planned first dose of CFT8634
4. Prior treatment with BRD9 degrader

5. Subject has central nervous system (CNS) involvement (primary tumor or metastatic disease), except in the following circumstances:

   1. Subjects with previously treated brain metastases may be permitted to participate provided they are stable (without evidence of progression by imaging 14 days prior to the first dose of study drug and any neurologic symptoms have stabilized), have no evidence of new or enlarging brain metastases, and if they are taking corticosteroids, they are on stable or tapering doses for at least 7 days prior to first dose of study drug. Antiseizure therapy is permitted provided the medication is not otherwise excluded and seizures have been controlled for at least 28 days since the last antiseizure medication adjustment
   2. Subjects with asymptomatic brain metastases found on Screening magnetic resonance imaging (MRI) may be permitted to be entered into the study without prior radiation therapy to the brain if they do not require immediate surgical or radiation therapy in the opinion of the treating investigator and in the opinion of a radiation therapy or neurosurgical consultant
6. Subject has any evidence of a CNS bleed including intra-tumoral hemorrhage
7. Subject has known bleeding diathesis
8. Subject has impaired cardiac function or clinically significant cardiac disease (i.e. uncontrolled heart disease/hypertension, clinically significant arrythmias, unstable angina/myocardia infarction/stroke within 180 days prior to screening)
9. Subject with presence of inflammatory vascular disease or microangiopathy (eg, thrombotic microangiopathies, hemolytic uremic syndrome [HUS], atypical HUS)

10. Subject with known malignancy, other than study indication, that is progressing or has required treatment within the past 3 years

    a. Subject with basal cell carcinoma of the skin, squamous cell carcinoma of the skin, or carcinoma in situ (i.e. breast carcinoma, cervical cancer in situ) that have undergone potentially curative therapy are not excluded

11. Subject has received live, attenuated vaccine within 28 days prior to first dose administration
12. Subject with known history of human immunodeficiency virus (HIV) infection
13. Subject had a venous thrombosis within 14 days prior to first dose of study drug
14. Subject with gastrointestinal absorption issues (e.g., malabsorption syndrome or other illness that could affect oral absorption).
15. Concurrent administration of strong cytochrome P450 (CYP) 3A4 inhibitors and inducers, and multidrug resistance mutation 1 (MDR1) inhibitors.

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

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Dose Escalation Phase 1/Part1: CFT8634; Up to approximately 40 subjects ≥18 years of age or between ≥16 and <18 years of age and weighing ≥50 kg with locally advanced or metastatic SMARCB1-perturbed cancers, including synovial sarcoma and SMARCB1-null tumors, having received ≥ 1 prior anticancer therapy	Drug: CFT8634; Oral dose of CFT8634
Experimental: Dose Escalation Phase 1/Part 2: CFT8634; Up to approximately 6-12 subjects ≥12 and <16 years of age and weighing ≥40 kg or ≥16 and <18 years of age and weighing ≥40 kg and <50 kg with locally advanced or metastatic SMARCB1-perturbed cancers, including synovial sarcoma and SMARCB1-null tumors	Drug: CFT8634; Oral dose of CFT8634
Experimental: Phase 2 - Arm A: CFT8634; Approximately 30 subjects with locally advanced or metastatic synovial sarcoma at the recommended phase 2 dose (RP2D) having received 1-2 prior anticancer therapies	Drug: CFT8634; Oral dose of CFT8634
Experimental: Phase 2 - Arm B: CFT8634; Approximately 20 subjects with locally advanced or metastatic SMARCB1-null tumors at the RP2D having received ≥1 prior anticancer therapy	Drug: CFT8634; Oral dose of CFT8634

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Frequency and severity of AEs and serious adverse events (SAEs)	Phase 1 and Phase 2	From screening until at least 30 days after completion of study treatment
Number of subjects with changes between baseline and post-baseline safety assessments based on safety laboratory results graded by CTCAE v5.0	Phase 1 and Phase 2	From screening until at least 30 days after completion of study treatment
Frequency of dose interruptions and dose reductions	Phase 1 and Phase 2	From first dose until end of treatment
Incidence of dose limiting toxicities (DLTs)	Phase 1 only	From first dose until 28 days after first dose
Overall Response Rate (ORR)	Phase 2 only according to RECIST v1.1 criteria	Up to approximately 24 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Overall Survival (OS)	OS is defined as the time from first dose of study treatment to the date of death, irrespective of the cause of death. (Phase 2 only)	Up to approximately 48 months
Plasma concentration of CFT8634 to characterize the pharmacokinetics (PK) parameters of CFT8634	Plasma concentration of CFT8634 at the scheduled timepoints	At multiple time points up to approximately 24 weeks
Asses dose proportionality assessment	Dose proportionately assessment at the scheduled timepoints	At multiple time points up to approximately 24 weeks
Assess the pharmacodynamics by percent reduction from baseline of target protein	Tumor BRD9 degradation at scheduled timepoints	At multiple time points up to approximately 24 weeks
ORR	Phase 1 only according to RECIST v1.1 criteria	Up to approximately 24 months
Duration of Response (DOR)	DOR defined as time from first assessment of PR or CR to follow-on first assessment of progressive disease (PD)	Up to approximately 24 months
Progression Free Survival (PFS)	PFS defined as the time from first treatment received until PD is assessed	Up to approximately 24 months
Time to next treatment	Interval from the date of initiation of a treatment to the date of commencement of the next line of therapy	Up to approximately 8 months

Collaborators and Investigators

• Sponsor: C4 Therapeutics, Inc.

Study record dates

Study Major Dates

• Study Start (Actual): March 25, 2022
• Primary Completion (Actual): December 19, 2023
• Study Completion (Actual): December 19, 2023

Study Registration Dates

• First Submitted: April 23, 2022
• First Submitted That Met QC Criteria: April 29, 2022
• First Posted (Actual): May 2, 2022

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: December 12, 2024
• Last Verified: December 1, 2024

More Information

Terms related to this study

• Keywords: Soft Tissue Sarcoma; Chordoma; Epithelioid Sarcoma; Synovial Sarcoma; SMARB1-Null Tumors; CFT8634; Myoepithelial Carcinoma; Extraskeletal Myxoid Chondrosarcoma; Renal Medullary Carcinoma
• Additional Relevant MeSH Terms: Neoplasms; Neoplasms by Histologic Type; Neoplasms, Connective and Soft Tissue; Neoplasms, Connective Tissue; Sarcoma; Sarcoma, Synovial
• Other Study ID Numbers: CFT8634-1101

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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