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Combining CRLX101, a Nanoparticle Camptothecin, With Enzalutamide in People With Progressive Metastatic Castration Resistant Prostate Cancer Following Prior Enzalutamide Treatment

A Single Arm Phase II Study Combining CRLX101, a Nanoparticle Camptothecin, With Enzalutamide in Patients With Progressive Metastatic Castration Resistant Prostate Cancer Following Prior Enzalutamide Treatment

Status
Terminated
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03531827
Enrollment
4
Registered
2018-05-22
Start date
2019-03-26
Completion date
2021-06-01
Last updated
2022-07-12

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Metastatic Castration Resistant Prostate Cancer, Prostate Neoplasms

Keywords

Androgen Receptor Antagonist, PSA, Hormonal Therapy, Nanoparticle Drug, Antitumor

Brief summary

Background: Some prostate cancer keeps growing even when testosterone in the body drops to very low levels. This is called castrate-resistant prostate cancer. One treatment is enzalutamide. This is a modern hormonal therapy. But it only works for a certain amount of time and then the cancer becomes resistant to it. Researchers want to see if adding the treatment CRLX101 (formerly IT-101) could make enzalutamide work again for people who have already had it. Objective: To test a new way of treating prostate cancer using CRLX101 plus enzalutamide in people with certain prostate cancer who already had enzalutamide treatment. Eligibility: Adults ages 18 years and older with metastatic, castration-resistant prostate cancer who have had enzalutamide treatment Design: Participants will be screened with a medical history and physical exam. They will have blood and urine tests. They will have a scan of the chest/abdomen/pelvis. They will have a bone scan. Participants will get treatment in cycles. A cycle lasts 28 days. They will take enzalutamide by mouth once a day. They will get CRLX101 through an intravenous (IV) every 1 or 2 weeks. Participants will repeat screening tests throughout the study. Participants will have a follow-up visit 3-4 weeks after they stop taking the study drug. They will repeat most screening tests and have an electrocardiogram.

Detailed description

Background: * Enzalutamide is established as first-line hormonal therapy in participants with metastatic castration resistant prostate cancer (mCRPC). However, it is increasingly recognized that acquired resistance to therapy (e.g., androgen receptor (AR) overexpression, androgen receptor variant 7 (AR-V7) could limit the durability of response to therapy * Upregulation of Hypoxia-inducible factor 1-alpha (HIF-1Alpha) in hypoxic tumor cells provides a mechanism of acquired resistance to current hormonal therapies and chemotherapies. Acquired resistance increases angiogenesis and metastasis, leading to disease progression * Targeting the hypoxia driven tumor microenvironment (e.g., down-regulation of HIF-1Alpha) in addition to the androgen receptor (e.g., enzalutamide) has synergistic activity against prostate cancer cell line models (e.g., LNCaP, 22Rv1). * CRLX101 is a nanoparticle drug conjugate composed of 20(S)-camptothecin (a potent and highly selective topoisomerase I inhibitor with anti-HIF-1Alpha properties) conjugated to a linear, cyclodextrin-polyethylene glycol-based polymer * CRLX101 has been shown to be safe, tolerable, and efficacious in numerous Phase II clinical investigations in a variety of tumor subtypes. * Preclinical and clinical studies have shown CRLX101 significantly down-regulates HIF-1alpha, impacting tumor-driven angiogenesis. * The treatment combination of CRLX101 and enzalutamide provides a reasonable approach to re-sensitizing prostate cancer cells to hormonal therapy via synergistic antitumor activity and inhibition of acquired resistance Objectives: -Primary Objective: To evaluate the anti-tumor activity of CRLX101 at the recommended phase II dose (RP2D) in combination with enzalutamide with respect to treatment response, defined as greater than or equal to 50% PSA decline or stable disease on imaging following 5 months of treatment. Eligibility: * Patients must have progressive mCRPC per Prostate Cancer Working Group 3(PCWG3) * Patients must be at least 18 years of age and able to give informed consent * Eastern Cooperative Oncology Group (ECOG) Performance Status less than or equal to 2 * Evaluable metastatic disease on bone scan or measurable disease on computed tomography (CT) Scan per PCWG3 and/or Response Evaluation Criteria in Solid Tumors (RECIST) * Patients must have had disease progression while receiving prior enzalutamide treatment Design: * The study will be conducted using an optimal two stage Phase II design (8 participants, expandable to 21 participants total) aimed to determine the percentage of participants with a prostate-specific antigen (PSA) decline of greater than 50% or stable disease at 5 months. * The first 3 to 6 participants enrolled on study will follow a lead-in dosing scheme to confirm the safety of the combination (CRLX101 12 mg/m(2) every 2 weeks for the first two cycles, followed by CRLX101 15 mg/m(2) every 2 weeks at the start of cycle 3, with enzalutamide 160 mg administered once daily starting on cycle 1 day 2) prior to initiation of the optimal two stage study design. * For participants enrolled on study following the lead-in, the confirmed tolerable dose of CRLX101 will be administered via intravenous (IV) infusion every 2 weeks. Enzalutamide 160 mg will be administered orally once daily beginning on cycle 1 day 2. * Blood and urine will be collected at multiple time points for pharmacokinetic (PK) and pharmacodynamic (PD0 analyses. * Tumor assessments will be made using Technetium-99 (99Tc) bone scintigraphy and/or CT scan (chest, abdomen, and pelvis) at baseline, prior to Cycle 3 and every 3 cycles thereafter. * The accrual ceiling for the study is set at 30 participants.

Interventions

DRUGenzalutamide

enzalutamide is an androgen receptor (AR) antagonist that is standard care therapy for metastatic prostate cancer

CRLX101 is a nanoparticle-drug conjugate (NDC) comprised of a linear cyclodextrin-polyethylene glycol-base polymer conjugated to multiple 2 (S)-camptothecin (CPT) molecules (Poly-CD-PEG-Camptothecin)

Sponsors

National Cancer Institute (NCI)
Lead SponsorNIH

Study design

Allocation
NON_RANDOMIZED
Intervention model
SEQUENTIAL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
MALE
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* INCLUSION CRITERIA: * Patients must have histologically or cytologically confirmed prostate cancer confirmed by either the Laboratory of Pathology at the national Institutes of Health (NIH) Clinical Center or Walter Reed National Military Medical Center at Bethesda prior to starting this study. If no pathological specimen is available, patients may enroll with a pathologist's report showing a histological diagnosis of prostate cancer and clinical course consistent with the disease. * Patients must have progressive metastatic castration-resistant prostate cancer mCRPC. There must be radiographic evidence of disease progression or biochemically (rising prostate-specific antigen (PSA) levels on successive measurements) recurring disease despite adequate testosterone suppression. * Progression must be evidenced and documented by any of the following parameters: * PSA progression defined by a minimum of two rising PSA levels with an interval of greater than or equal to 1 week between each determination * Appearance of one or more new lesions consistent with prostate cancer on bone scan * New or growing lesions on computed tomography (CT) scan * Patients must have metastatic disease, per Response Evaluation Criteria in Solid Tumors (RECIST) 1.1(64). * Patients must have received treatment with prior enzalutamide for two or more cycles and must have had evidence of disease progression while on enzalutamide. * Patients who have received antiandrogens such as flutamide, bicalutamide, or nilutamide for \>6 months immediately before enrollment on this study must be off treatment for 4 weeks (6 weeks for bicalutamide) and demonstrate a continued rise in PSA. Patients on antiandrogens for \<6 months must be off medication for 2 weeks. * Age greater than or equal to 18 years. Because no dosing or adverse event data are currently available on the use of enzalutamide and CRLX101 in patients \<18 years of age and prostate cancer is not common in children \<18 years of age, children are excluded from this study. * Patients must have adequate organ and marrow function as defined below: * leukocytes greater than or equal to 3,000/mcL * absolute neutrophil count greater than or equal to 1,500/mcL * platelets greater than or equal to 100,000/mcL * total bilirubin within normal institutional limits; for patients with Gilberts syndrome, total bilirubin less than or equal to 3.0 mg/dL * hemoglobin greater than or equal to 9g/dL * serum albumin greater than or equal to 2.8 g/dL * Aspartate aminotransferase (AST) Serum glutamic oxaloacetic transaminase (SGOT)/alanine aminotransferase (ALT)Serum glutamic-pyruvic transaminase (SGPT) less than or equal to 2.5 times institutional upper limit of normal (\<5 times institutional ULN for liver metastases) * creatinine within 1.5 times normal institutional limits OR --creatinine clearance greater than or equal to 60 mL/min/1.73 m(2) for patients with creatinine levels above institutional normal. * Patients must have castrate levels of testosterone (\<50 ng/dL \[1.74 nmol/L\]). * Patients must have undergone bilateral surgical castration or must continue on gonadotropin-releasing hormone (GnRH) agonists/antagonists for the duration of the study. * Patients on 5-alpha reductase inhibitors such as finasteride or dutasteride must stop medication at least 28 days prior to study entry. * The effects of enzalutamide and CRLX101 (formerly IT-101) on the developing human fetus are unknown. For this reason and because androgen receptor antagonists and topoisomerase I inhibitors as well as other therapeutic agents used in this trial are known to be teratogenic, all study subjects must agree to use a condom during the study treatment period and for 120 days following the last dose of study drug. Should a woman become pregnant or suspect she is pregnant while her partner is participating in this study, she should inform her treating physician immediately. * Eastern Cooperative Oncology Group (ECOG) performance status less than or equal to 2 (Karnofsky greater than or equal to 60%). * Ability of subject to understand and the willingness to sign a written informed consent document.

Exclusion criteria

* Patients who are receiving any other investigational agents. A minimum washout period of 28 days is required prior to the initiation of on study treatment unless the patient is receiving immunotherapy, for which the minimum washout period will be 14 days. This is because Immune-related toxicities are distinct and unlikely to synergize with this protocol therapy, a shorter washout period is reasonable and customary in clinical trials. * Patients who have been treated with prior secondary hormonal manipulations with proposed investigational rationale for having efficacy against androgen receptor variant 7 (AR-V7) splice variants. This includes but is not limited to Ralaniten (EPI-002) and AZD5312 (IONIS-AR-2.5Rx). (Note: patients previously treated with abiraterone, orteronel (TAK-700), apalutamide (ARN-509), galeterone, or VT-464 (formerly INO-464) will be eligible for this study. Patients who have received prior chemotherapy will also be eligible for this study). * Patients with known brain metastases should be excluded from this clinical trial because of their poor prognosis and because they often develop progressive neurologic dysfunction that would confound the evaluation of neurologic and other adverse events. * Patients with a recent (within 1 year) history of seizure or any condition that, in the opinion of the investigator, significantly increases seizure risk. Also, current or prior treatment with anti-epileptic medications for the treatment of seizures. Transient ischemic attack within 12 months prior to study enrollment will not be permitted. * History of allergic reactions attributed to compounds of similar chemical or biologic composition to enzalutamide, CRLX101, or other agents used in study. * Patients with a history within the last 3 years of another invasive malignancy (localized non-melanoma skin and bladder cancers are allowed). * Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, uncontrolled hypertension (systolic blood pressure (SBP)\>170/diastolic blood pressure (DBP)\>105), or psychiatric illness/social situations within 6 months that would limit compliance with study requirements. * Patients who have received palliative radiotherapy within 2 weeks of study entry and have not recovered to Grade 1 or baseline from associated toxicities. Note: Patients may receive palliative radiation once enrolled on study. The subject has not recovered to baseline or Common Terminology Criteria for Adverse Events (CTCAE) less than or equal to Grade 1 from toxicity due to all prior therapies, including surgery, except alopecia and other non-clinically significant adverse events (AEs). * Patients who are unable to swallow tablets or have a gastrointestinal disease that could hinder the absorption of enzalutamide * The use of any herbal products that may lower prostate-specific antigen (PSA) levels (e.g., saw palmetto). * Patients with microscopic hematuria (defined as \>100 red blood cells (RBCs) on urinalysis) or worsening urinary symptoms within 7 days prior to the initiation of study treatment. * Known human immunodeficiency virus (HIV)-positive patients on antiretroviral therapy are ineligible because of potential pharmacokinetic interactions with study drugs. However, patients with long-standing (\>5 years) HIV on antiretroviral therapy \>1 month (undetectable HIV viral load and cluster of differentiation 4 (CD4) count \> 150 cells/micro L) may be eligible if the Principal Investigator or designee determines no anticipated clinically significant drug-drug interactions. INCLUSION OF MINORITIES AND WOMEN: -Men of all races and ethnic groups are eligible for this trial. Women are excluded as prostate cancer does not exist in this population.

Design outcomes

Primary

MeasureTime frameDescription
Percentage of Participants With Anti-tumor Activity5 monthsAnti-tumor activity is \>=50% prostate-specific antigen (PSA) decline or stable disease on imaging following 5 months of treatment in participants with progressive metastatic castration resistant prostate cancer (mCRPC) following enzalutamide treatment. Stable disease (SD) is neither sufficient shrinkage to qualify for partial response (at least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum of diameters) nor sufficient increase to qualify for progressive disease (at least a 20% increase in the sum of the diameters of target lesions, taking as reference the smallest sum on study).

Secondary

MeasureTime frameDescription
Proportion of Participants With a Sustained >30% Decline in Prostate-specific Antigen (PSA)time of sustained >30% decline in prostate-specific antigen (PSA) from baseline, approximately >1 monthProportion of participants with a sustained \>30% decline in prostate-specific antigen (PSA) from baseline based on all evaluable participants.
Overall Survival (OS)time from the start of treatment to the time of death, up to 17.5 monthsOS is defined as the duration of time from the start of treatment to the time of death estimated based on all evaluable participants.
Number of Participants With a Change in Measurable Disease From Baseline as Determined by Response Evaluation Criteria in Solid Tumors (RECIST)Within 6 monthsNumber of participants with a change in measurable disease as determined by RECIST. Complete response (CR) is disappearance of all target lesions. Partial response (PR) is at least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum of diameters. Progressive disease (PD) is at least a 20% increase in the sum of the diameters of target lesions, taking as reference the smallest sum on study. Stable disease (SD) is neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum of diameters while on study.
Number of Participants With a Change in Measurable Disease as Determined by the Prostate Cancer Working Group 3 (PCWG3)Study end, approximately 6 monthsNumber of participants with a change in measurable disease as determined by the Prostate Cancer Working Group 3 (PCWG3). PSA values will be captured at each visit and PSA declines and progression (by radiographic evidence or clinical symptoms) will be followed. Radiographic disease progression is considered if a minimum of two new lesions is observed on bone scan. Clinical disease progression is the need for chemotherapy or other change in therapy based on increased cancer related symptoms.

Other

MeasureTime frameDescription
Number of Participants With Serious and/or Non-serious Adverse Events Assessed by the Common Terminology Criteria for Adverse Events (CTCAE v4.0)Date treatment consent signed to date off study, approximately 26 months and 6 days.Here is the number of participants with serious and/or non-serious adverse events assessed by the Common Terminology Criteria for Adverse Events (CTCAE v4.0). A non-serious adverse event is any untoward medical occurrence. A serious adverse event is an adverse event or suspected adverse reaction that results in death, a life-threatening adverse drug experience, hospitalization, disruption of the ability to conduct normal life functions, congenital anomaly/birth defect or important medical events that jeopardize the patient or subject and may require medical or surgical intervention to prevent one of the previous outcomes mentioned.

Countries

United States

Participant flow

Participants by arm

ArmCount
1/Lead-In Safety: CRLX101 With Enzalutamide
Lead-in Dosing: CRLX101 (formerly IT-101) 12mg/m\^2 every (q) 2 weeks x 2 cycles; CRLX101 15mg/m\^2 (q) 2 weeks cycle 3+; enzalutamide 160 mg every day (QD) cycle 1 day 2+
4
Total4

Withdrawals & dropouts

PeriodReasonFG000FG001
Overall StudyAdverse Event20
Overall StudyProgressive disease10

Baseline characteristics

Characteristic1/Lead-In Safety: CRLX101 With Enzalutamide
Age, Categorical
<=18 years
0 Participants
Age, Categorical
>=65 years
4 Participants
Age, Categorical
Between 18 and 65 years
0 Participants
Age, Continuous72.65 years
STANDARD_DEVIATION 3.37
Ethnicity (NIH/OMB)
Hispanic or Latino
0 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
4 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants
Median Prior Lines of Therapy4.5 Lines of therapy
Median Prostate-Specific Antigen (PSA)93.7 ng/ml
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
Race (NIH/OMB)
Asian
0 Participants
Race (NIH/OMB)
Black or African American
1 Participants
Race (NIH/OMB)
More than one race
0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants
Race (NIH/OMB)
White
3 Participants
Region of Enrollment
United States
4 participants
Sex: Female, Male
Female
0 Participants
Sex: Female, Male
Male
4 Participants

Adverse events

Event typeEG000
affected / at risk
deaths
Total, all-cause mortality
1 / 4
other
Total, other adverse events
4 / 4
serious
Total, serious adverse events
3 / 4

Outcome results

Primary

Percentage of Participants With Anti-tumor Activity

Anti-tumor activity is \>=50% prostate-specific antigen (PSA) decline or stable disease on imaging following 5 months of treatment in participants with progressive metastatic castration resistant prostate cancer (mCRPC) following enzalutamide treatment. Stable disease (SD) is neither sufficient shrinkage to qualify for partial response (at least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum of diameters) nor sufficient increase to qualify for progressive disease (at least a 20% increase in the sum of the diameters of target lesions, taking as reference the smallest sum on study).

Time frame: 5 months

ArmMeasureGroupValue (NUMBER)
1/Lead-In Safety: CRLX101 With EnzalutamidePercentage of Participants With Anti-tumor Activity>=50% prostate-specific antigen (PSA) decline25 percentage of participants
1/Lead-In Safety: CRLX101 With EnzalutamidePercentage of Participants With Anti-tumor ActivityStable Disease0 percentage of participants
Secondary

Number of Participants With a Change in Measurable Disease as Determined by the Prostate Cancer Working Group 3 (PCWG3)

Number of participants with a change in measurable disease as determined by the Prostate Cancer Working Group 3 (PCWG3). PSA values will be captured at each visit and PSA declines and progression (by radiographic evidence or clinical symptoms) will be followed. Radiographic disease progression is considered if a minimum of two new lesions is observed on bone scan. Clinical disease progression is the need for chemotherapy or other change in therapy based on increased cancer related symptoms.

Time frame: Study end, approximately 6 months

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
1/Lead-In Safety: CRLX101 With EnzalutamideNumber of Participants With a Change in Measurable Disease as Determined by the Prostate Cancer Working Group 3 (PCWG3)0 Participants
Secondary

Number of Participants With a Change in Measurable Disease From Baseline as Determined by Response Evaluation Criteria in Solid Tumors (RECIST)

Number of participants with a change in measurable disease as determined by RECIST. Complete response (CR) is disappearance of all target lesions. Partial response (PR) is at least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum of diameters. Progressive disease (PD) is at least a 20% increase in the sum of the diameters of target lesions, taking as reference the smallest sum on study. Stable disease (SD) is neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum of diameters while on study.

Time frame: Within 6 months

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
1/Lead-In Safety: CRLX101 With EnzalutamideNumber of Participants With a Change in Measurable Disease From Baseline as Determined by Response Evaluation Criteria in Solid Tumors (RECIST)0 Participants
Secondary

Overall Survival (OS)

OS is defined as the duration of time from the start of treatment to the time of death estimated based on all evaluable participants.

Time frame: time from the start of treatment to the time of death, up to 17.5 months

Population: 3/4 participants were analyzed because one participant was lost to follow-up.

ArmMeasureValue (MEDIAN)
1/Lead-In Safety: CRLX101 With EnzalutamideOverall Survival (OS)3.9 Months
Secondary

Proportion of Participants With a Sustained >30% Decline in Prostate-specific Antigen (PSA)

Proportion of participants with a sustained \>30% decline in prostate-specific antigen (PSA) from baseline based on all evaluable participants.

Time frame: time of sustained >30% decline in prostate-specific antigen (PSA) from baseline, approximately >1 month

ArmMeasureValue (NUMBER)
1/Lead-In Safety: CRLX101 With EnzalutamideProportion of Participants With a Sustained >30% Decline in Prostate-specific Antigen (PSA)0 proportion of participants
Other Pre-specified

Number of Participants With Serious and/or Non-serious Adverse Events Assessed by the Common Terminology Criteria for Adverse Events (CTCAE v4.0)

Here is the number of participants with serious and/or non-serious adverse events assessed by the Common Terminology Criteria for Adverse Events (CTCAE v4.0). A non-serious adverse event is any untoward medical occurrence. A serious adverse event is an adverse event or suspected adverse reaction that results in death, a life-threatening adverse drug experience, hospitalization, disruption of the ability to conduct normal life functions, congenital anomaly/birth defect or important medical events that jeopardize the patient or subject and may require medical or surgical intervention to prevent one of the previous outcomes mentioned.

Time frame: Date treatment consent signed to date off study, approximately 26 months and 6 days.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
1/Lead-In Safety: CRLX101 With EnzalutamideNumber of Participants With Serious and/or Non-serious Adverse Events Assessed by the Common Terminology Criteria for Adverse Events (CTCAE v4.0)4 Participants

Source: ClinicalTrials.gov · Data processed: Mar 1, 2026