A Study of CBX 12 in Subjects With Platinum Resistant or Refractory Ovarian Cancer

A Randomized Phase 2 Study of CBX 12 in Subjects With Platinum Resistant or Refractory Ovarian Cancer

The purpose of this study is to assess the safety, tolerability, and efficacy of CBX-12 in female subjects with platinum resistant or refractory ovarian cancer at 2 doses; 125 mg/m2 every 21 days or 100 mg/m2 every 21 days.

Study Overview

• Status: Terminated
• Conditions: Platinum-resistant Ovarian Cancer; Refractory Ovarian Carcinoma
• Intervention / Treatment: Drug: CBX-12

• Study Type: Interventional
• Enrollment (Actual): 40
• Phase: Phase 2

Contacts and Locations

Study Locations

• United States
  • Arizona
    • Tucson, Arizona, United States, 85711
      • TMC Health

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Subjects must have histologically- or cytologically-diagnosed epithelial high-grade serous cancer of the ovary, fallopian tube cancer or primary peritoneum cancer that is refractory to prior therapy and must have platinum-resistant disease defined as:

  • Subjects who have received only 1 platinum-based chemotherapy regimen for at least 4 cycles of platinum must have disease progression on treatment or occurring ≤ 26 weeks after their last dose of platinum.
  • Patients who have progressed following a second course of a platinum based regimen.
  • Subjects may have up to 2 additional systemic regimens for advanced or metastatic disease. Maintenance regimens (e.g., with a PARP inhibitor or bevacizumab) are not considered separate regimens.
• Age greater than or equal to 18 years at the time of signing the informed consent form (ICF).
• Has measurable disease per RECIST 1.1.
• Has provided written informed consent.
• Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1.
• Adequate liver, renal, hematologic, pulmonary and coagulation function.

Exclusion Criteria:

• Cytotoxic chemotherapy, biologic agent, investigational agent, or radiation therapy within 3 weeks prior to the first dose of CBX-12.
• Subjects who are currently receiving any other anticancer or investigational agent(s).
• Clinically significant intercurrent disease.
• Active human immunodeficiency virus (HIV) infection.
• Active hepatitis B or C infection.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: CBX-12 - 125mg/m2 q21d; 125mg/m2 CBX-12 administered by intravenous (IV) infusion every 21 days. Treatment will continue until there is evidence of progressive disease (PD) or development of unacceptable toxicity.	Drug: CBX-12; CBX-12 is an alphalex construct which contains exatecan as the pharmacologically active moiety.
Experimental: CBX-12 - 100mg/m2 q21d; 100mg/m2 CBX-12 administered by intravenous (IV) infusion every 21 days. Treatment will continue until there is evidence of progressive disease (PD) or development of unacceptable toxicity.	Drug: CBX-12; CBX-12 is an alphalex construct which contains exatecan as the pharmacologically active moiety.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of Subjects With Complete Response (CR) or Partial Response (PR) [Objective Response Rate (ORR)]	ORR is defined as the proportion of subjects achieving a confirmed best overall response (BOR) of CR or PR defined using Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 criteria.	Randomization to progressive disease (PD) (Up to approximately 21 months)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of Subjects With Treatment Emergent Adverse Events (TEAEs)	Safety as assessed by the incidence of treatment-emergent AEs (TEAEs).	First dose of study drug to 30-day post-dose follow up (Up to approximately 21 months)
Median Duration of Response (DoR)	Duration of response is the interval from the date of initial CR or PR until the first date criteria for PD is met using RECIST v1.1 criteria, or initiation of other (or additional) antitumor therapy is first reported, or death due to any cause.	Date of Initial CR or PR to PD (Up to 21 Months)
Progression-Free Survival (PFS)	PFS is defined as the time from the day of randomization to the first evidence of progression as defined by RECIST (RECIST v1.1) criteria or death from any cause.	Randomization to PD or Date of Death (Up to 21 Months)
Plasma levels of CBX-12 (AUC0-24hr)	Assessment of pharmacokinetic (PK) variable AUC0-24hr	At 1st dose of study drug (pre-dose, end of infusion (EOI), 1, 2, and 4 hours post EOI), and 10-14 days post 1st dose
Plasma levels of CBX-12 (Cmax)	Assessment of pharmacokinetic (PK) variable Cmax	At 1st dose of study drug (pre-dose, end of infusion (EOI), 1, 2, and 4 hours post EOI), and 10-14 days post 1st dose
Plasma levels of CBX-12 (Tmax)	Assessment of pharmacokinetic (PK) variable Tmax	At 1st dose of study drug (pre-dose, end of infusion (EOI), 1, 2, and 4 hours post EOI), and 10-14 days post 1st dose
Plasma levels of CBX-12 (T1/2)	Assessment of pharmacokinetic (PK) variable T1/2	At 1st dose of study drug (pre-dose, end of infusion (EOI), 1, 2, and 4 hours post EOI), and 10-14 days post 1st dose
Plasma levels of Exatecan (AUC0-24hr)	Assessment of pharmacokinetic (PK) variable AUC0-24hr	At 1st dose of study drug (pre-dose, end of infusion (EOI), 1 hour post EOI, 2 hours post EOI, 4 hours post EOI), and 10-14 days post 1st dose
Plasma levels of Exatecan (Cmax)	Assessment of pharmacokinetic (PK) variable Cmax	At 1st dose of study drug (pre-dose, end of infusion (EOI), 1 hour post EOI, 2 hours post EOI, 4 hours post EOI), and 10-14 days post 1st dose
Plasma levels of Exatecan (Tmax)	Assessment of pharmacokinetic (PK) variable Tmax	At 1st dose of study drug (pre-dose, end of infusion (EOI), 1 hour post EOI, 2 hours post EOI, 4 hours post EOI), and 10-14 days post 1st dose
Plasma levels of Exatecan (T1/2)	Assessment of pharmacokinetic (PK) variable T1/2	At 1st dose of study drug (pre-dose, end of infusion (EOI), 1 hour post EOI, 2 hours post EOI, 4 hours post EOI), and 10-14 days post 1st dose

Collaborators and Investigators

• Sponsor: Cybrexa Therapeutics
• Investigators: Study Director: Michael Needle, MD, Cybrexa Therapeutics

Study record dates

Study Major Dates

• Study Start (Actual): September 25, 2024
• Primary Completion (Actual): October 31, 2025
• Study Completion (Actual): October 31, 2025

Study Registration Dates

• First Submitted: March 7, 2024
• First Submitted That Met QC Criteria: March 14, 2024
• First Posted (Actual): March 18, 2024

Study Record Updates

• Last Update Posted (Actual): August 20, 2026
• Last Update Submitted That Met QC Criteria: August 19, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Endocrine System Diseases; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Genital Diseases, Female; Endocrine Gland Neoplasms; Ovarian Diseases; Adnexal Diseases; Genital Neoplasms, Female; Gonadal Disorders; Ovarian Neoplasms
• Other Study ID Numbers: CBX-12-201

Drug and device information, study documents

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