ESK981 in Treating Patients With Metastatic Castrate-Resistant Prostate Cancer

PRIMARY OBJECTIVES:

I. To determine the PSA >= 50% response rate (PSA50) from baseline using the Prostate Cancer Working Group 3 (PCWG3) criteria to pan-VEGFR/TIE2 tyrosine kinase inhibitor CEP-11981 (ESK981) as a single agent in men with castration-resistant prostate cancer (CRPC) who have progressed on enzalutamide (an oral androgen-receptor inhibitor) and/or abiraterone acetate (an androgen synthesis inhibitor).

II. To assess the safety and tolerability of ESK981 as a single agent.

SECONDARY OBJECTIVES:

I. To determine the time to PSA response to ESK981 in metastatic CRPC patients. II. To determine the duration of PSA response to ESK981 in metastatic CRPC patients.

III. To determine PSA progression rates and PSA progression free survival (PFS), as defined by the PCWG3 criteria.

TERTIARY OBJECTIVES:

I. To assess exploratory biomarkers from blood and tumor biopsies.

OUTLINE:

Patients receive pan-VEGFR/TIE2 tyrosine kinase inhibitor CEP-11981 orally (PO) once daily (QD) for 5 days (Monday-Friday). Treatment repeats for up to 8 weeks in the absence of disease progression or unacceptable toxicity. If treatment is successful after 8 weeks, patients may receive up to 6 months of pan-VEGFR/TIE2 tyrosine kinase inhibitor CEP-11981.

After completion of study treatment, patients are followed up periodically.

• ESK981 (Drug): Treatment with ESK981 for patients with metastatic castrate resistant prostate cancer

Primary outcomes

• PSA Decline of >= 50% (PSA50) From Baseline [Up to 1 year]: PSA decline of >= 50% (PSA50) from baseline using Prostate Cancer Working Group 3 (PCWG3) definition with point estimate and (1-sided Wilson type 90% lower) confidence interval (CI) estimates.

Secondary outcomes

• Duration of PSA Response (RD) [From start of PSA50 until PSA progression, assessed up to 1 year]: Will be summarized with the Kaplan-Meier (K-M) survivorship estimate. A graph of the K-M curve for RD will be generated along with the Hall-Wellner 90% confidence band, and a display of the number of patients at risk at several time points, below the X-axis. Summary statistics (6-month rate, 12-month rate, median, etc.) will be calculated from the K-M life table, each one with its respective 80% CI.
• PSA Progression Free Survival (PFS) [Date that a 25% or greater increase and an absolute increase of 2.0 ng/mL or more from the nadir is documented and confirmed by a second value obtained 3 or more weeks later, assessed up to 1 year]: Will be summarized with the Kaplan-Meier (K-M) survivorship estimate. A graph of the K-M curve for PFS will be generated along with the Hall-Wellner 90% confidence band, and a display of the number of patients at risk at several time points, below the X-axis. Summary statistics (6-month rate, 12-month rate, median, etc.) will be calculated from the K-M life table, each one with its respective 80% CI.
• Time to PSA Response [From treatment start until the first documented occurrence of PSA50, assessed up to 1 year]: Will be used to summarize the time to PSA response. These descriptives will include sample size (N), median, mean, standard deviation (SD), interquartile range (IQR), minimum, and maximum.

Other outcomes

• Androgen Receptor (AR) Signaling [Up to 1 year]: Will examine the association of somatic and germline mutations with exceptional response/resistance to pan-VEGFR/TIE2 tyrosine kinase inhibitor CEP-11981.
• Circulating and Disseminated Tumor Cells as Pharmacodynamic Biomarkers [Up to 1 year]: Number of Circulating and disseminated tumor cells per 7.5ml as a pharmacodynamic biomarker.
• ETS/Kinase Gene Fusions [Up to 1 year]: Will examine the association of somatic and germline mutations with exceptional response/resistance to pan-VEGFR/TIE2 tyrosine kinase inhibitor CEP-11981.
• Metastatic Kinome Activity Profiles as Predictive Biomarkers [Up to 1 year]: Description of immunohistochemistry of the kinases, graded 0,1,2,3
• Immunohistochemistry (IHC) of Protein Markers [Up to 1 year]: Ki67, Receptor, CD31, NG2, desmin, PDGFR1/2, VEGFR1/2 immunohistochemistry graded 0, 1, 2, 3
• DNA Sequencing of Prostate Tumor [Up to 1 year]: copy number, Loss of heterozygosity, mutation, amplification, graded 0,1

Sex: Male, ages: 18 Years to any

Inclusion Criteria:

* Have signed an informed consent document indicating that the subject understands the purpose of and procedures required for the study and are willing to participate in the study
* Be willing/able to adhere to the prohibitions and restrictions specified in this protocol
* Eastern Cooperative Group (ECOG) performance status =< 1
* Patient must have evidence of castrate resistant prostate cancer as evidenced by a confirmed rising PSA (per PCWG3 criteria) and a castrate serum testosterone level (i.e. =< 50 mg/dL)
* Documented histologically confirmed adenocarcinoma of the prostate
* Metastatic prostate cancer (M1) as documented by appropriate medical imaging (i.e. computed tomography \[CT\]-scan, positron emission tomography \[PET\] scan or bone scan)
* Treatment failure of either abiraterone and/or enzalutamide as evidenced by a confirmed rising PSA (per PCWG3 criteria) and a castrate serum testosterone level (i.e. =< 50 mg/dL) while receiving treatment with either abiraterone and/or enzalutamide
* Willingness to use contraception by a method that is deemed effective by the Investigator throughout the treatment period and for at least 30 days following the last dose of therapy
* Willingness and ability to comply with study procedures and follow-up examination
* Able to swallow and retain oral medication

Exclusion Criteria:

* Current systemic therapy (other than a gonadotrophin releasing hormone \[GnRH\] agonist/antagonist) for CRPC including:

  * CYP-17 inhibitors (e.g. ketoconazole, abiraterone)
  * Antiandrogens (e.g. bicalutamide, nilutamide)
  * Second generation antiandrogens (e.g. enzalutamide, ARN-509, Galeterone)
  * Immunotherapy (e.g. sipuleucel-T, ipilimumab)
  * Chemotherapy (e.g. docetaxel, cabazitaxel)
* Greater than 2 lines of prior systemic therapy for CRPC
* Prior chemotherapy (e.g. docetaxel, cabazitaxel) for CRPC; prior docetaxel administered in the castrate-sensitive space is allowed
* Prior radiopharmaceutical therapy (e.g. radium-223, strontium-89, samarium-153, etc.) within the past year
* Have any condition that, in the opinion of the investigator, would compromise the well-being of the subject or the study or prevent the subject from meeting or performing study requirements
* Absolute neutrophil count (ANC) less than 1500/mm\^3
* Platelet count less than 100000/mm\^3
* Hemoglobin less than 9 g/dL
* Bilirubin greater than 1.5 times the upper limit of normal (ULN)
* Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) greater than 2.0 times the ULN in the absence of known hepatic metastases, or ALT or AST greater than 3.0 times the ULN in the presence of known hepatic metastases
* The patient has a serum creatinine value greater than 1.5 mg/dL
* The patient has active brain metastases
* The patient is currently on warfarin or heparin therapy
* The patient has any pre-existing coagulopathy, recent hemoptysis, gross hematuria, or gastrointestinal bleeding, and a history of a clinically significant cardiovascular or cerebrovascular event within 12 months prior to study entry
* The patient has uncontrolled hypertension defined as a blood pressure measurement greater than 150 mm Hg systolic or 90 mm Hg diastolic with medication
* The patient has received any investigational drug within the past 4 weeks
* The patient has previously been enrolled in the study or received ESK981
* The patient has known hypersensitivity to gelatin or lactose monohydrate
* The patient has taken a medication known to be a potent inducer of CYP1A2, CYP2C8, or CYP3A4 within 4 weeks prior to the first dose of study drug
* The patient has taken a medication known to be a potent inhibitor of CYP1A2, CYP2C8, or CYP3A4 within 2 weeks prior to the first dose of study drug

Participant flow

Outcome results

• PSA Decline of >= 50% (PSA50) From Baseline (Primary), Number, percentage of participants: Treatment ESK981 7.7 (1.7 to 28.2)
• Duration of PSA Response (RD) (Secondary), Number, months: Treatment ESK981 1.9
• PSA Progression Free Survival (PFS) (Secondary), Median, months: Treatment ESK981 0.9 (0.2 to 1.9)
• Time to PSA Response (Secondary), Number, months: Treatment ESK981 10.0
• Androgen Receptor (AR) Signaling (Other pre specified)
• Circulating and Disseminated Tumor Cells as Pharmacodynamic Biomarkers (Other pre specified)
• ETS/Kinase Gene Fusions (Other pre specified)
• Metastatic Kinome Activity Profiles as Predictive Biomarkers (Other pre specified)
• Immunohistochemistry (IHC) of Protein Markers (Other pre specified)
• DNA Sequencing of Prostate Tumor (Other pre specified)

Adverse events

Time frame: 2 years

Serious adverse events by term

Other adverse events by term

• Results publication: Heath EI, Chen W, Heilbrun L, Choi JE, Dobson K, Smith M, Maj T, Vaishampayan U, Kryczek I, Zou W, Chinnaiyan AM, Qiao Y. Phase II trial of multi-kinase inhibitor ESK981 in patients with metastatic castration-resistant prostate cancer. Invest New Drugs. 2024 Oct;42(5):566-574. doi: 10.1007/s10637-024-01463-x. Epub 2024 Sep 3. PMID 39227508

• Study Protocol and Statistical Analysis Plan (PDF, 2019-07-02)

• Elisabeth I. Heath, Principal investigator, Barbara Ann Karmanos Cancer Institute

NIH grants: P30CA022453