CompletedNCT03480646Updated Oct 29, 2025Results posted

ProSTAR: A Study Evaluating CPI-1205 in Patients With Metastatic Castration Resistant Prostate Cancer

A Phase 1/2 interventional study of CPI-1205 and Cobicistat in Metastatic Castration Resistant Prostate Cancer (mCRPC), sponsored by Constellation Pharmaceuticals. Completed at 41 sites in United States. Open to male participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-10-29.

Sponsored by Constellation Pharmaceuticals · Phase 1/2, Interventional, and Treatment

From the registry’s dates

Registered 3 months after the study started (first participant enrolled Nov 2017, registered Mar 2018).

Phase: Phase 1/2
Study type: Interventional
Enrollment: 175
Allocation: Randomized
Ages: 18 Years and older
Sex: Male

Study summary

This was an open-label Phase 1b/2 study involving oral administration of CPI-1205 in combination with either enzalutamide or abiraterone/prednisone in male patients with metastatic Castration-Resistant Prostate Cancer. The study was designed to determine the maximum tolerated dose (MTD) and the recommended Phase II dose (RP2D) based on the safety, tolerability, pharmacokinetic, and efficacy profiles of CPI-1205 in combination with either enzalutamide or abiraterone/prednisone.

Following the determination of the MTD and RP2D, the study proceeded to Phase 2. Patients in Phase 2 received CPI-1205 at the RP2D in combination with either enzalutamide or abiraterone/prednisone versus either enzalutamide or abiraterone/prednisone as a control arm.

Read the detailed description

Study CPI-1205-201 was a Phase 1b/2, multi-center, open-label study of CPI-1205 alone and with cobicistat in subjects with mCRPC in combination with either enzalutamide or abiraterone/prednisone. The study initially had two phases: a Phase 1 dose-finding, dose-escalation study intended to establish the Recommended Phase 2 Dose (RP2D) of CPI-1205 for the Phase 2 portion.

The study underwent three amendments.

PHASE 1b In the Phase 1b dose-escalation phase and prior to Amendment 2, subjects were enrolled into Phase 1b dose level CPI-1205 PO three times daily (TID) + enzalutamide or abiraterone/prednisone.

In Amendment 2, new subjects were enrolled into cohorts including:

Dose-escalating CPI-1205 PO twice daily (BID) + fixed-dose cobicistat PO BID + enzalutamide Dose-escalating CPI-1205 PO BID + fixed-dose cobicistat PO BID + abiraterone/prednisone In Amendment 3, Phase 1b expansion cohort(s) were added in the heavily pretreated population (HPEC). An HPEC began enrollment if 0 out of 3 or 1 out of 6 subjects treated with a specific regimen (i.e., CPI-1205 with or without cobicistat, in combination with enzalutamide or abiraterone) at a given dose level during Phase 1b dose escalation experienced a dose-limiting toxicity (DLT).

Following determination of the maximum tolerated dose (MTD) in each of the CPI-1205 BID + cobicistat combinations (and possibly in the CPI-1205 TID combination) and after evaluation of the BID cohorts without cobicistat (if applicable), only one of the CPI-1205 dosing schedules was selected as the RP2D for each combination. One or both combinations proceeded to Phase 2 after consideration of pharmacokinetic (PK) and pharmacodynamic (PD) results, data from the HPEC(s), and safety data.

PHASE 2 If only one partner product was chosen for Phase 2, the study proceeded as an open-label randomized Phase 2 trial, with subjects randomized to either the combination arm (CPI-1205 at the RP2D [with or without cobicistat] in combination with enzalutamide or abiraterone/prednisone) or the control arm (enzalutamide or abiraterone/prednisone as monotherapy). If both partner products were chosen, the second Phase 2 was either a second open-label randomized trial or a single-arm Phase 2 trial (following a Simon's 2-stage design). The design of the second trial was determined by the Sponsor based on preliminary efficacy and PK.

CPI-1205 was administered orally TID or BID (as of Amendment 2). Cobicistat dosing began with one dose the evening prior to Day 1 of CPI-1205 and continued PO BID starting on Day 1. Enzalutamide and abiraterone were given PO once daily, and prednisone was given PO BID (or at the investigator's discretion).

Successive 28-day treatment cycles were repeated without planned breaks, as long as the combination was well tolerated, until radiographic disease progression, unequivocal clinical progression, or planned initiation of another systemic treatment. Investigators could continue treatment in subjects with progression in one site if other lesions might benefit. Subjects in the control arm who progressed had the option to cross over to the combination arm, provided they met eligibility criteria.

Conditions studied

Metastatic Castration Resistant Prostate Cancer (mCRPC)

Browse trials for

Neoplasms 10,818

Keywords

Phase 1/2
Oncology
EZH2 Inhibitor

In context

Neoplasms

10,818 studies on the registry are indexed under Neoplasms; 2,324 are open to participants now.

This study's enrollment of 175 is above the median of 60 across 7,703 interventional studies indexed under Neoplasms.

Browse Neoplasms studies →

Lead sponsor

Constellation Pharmaceuticals is the lead sponsor of 7 studies on the registry; none are open to participants now.

Counted across the registry records on this site, refreshed daily.

Who can participate

Ages eligible: 18 Years and older
Sexes eligible: Male
Accepts healthy volunteers: No

Eligibility criteria

PHASE 1b DOSE ESCALATION

Inclusion Criteria for Phase 1b Dose Escalation

Patients must meet all the following criteria to be enrolled in this study:

Age ≥ 18 years
(ECOG) Performance Status 0-1
of at least 12 weeks
or cytologically confirmed adenocarcinoma of the prostate (pure small cell carcinoma excluded)
Documented disease
Must have undergone bilateral orchiectomy (surgical castration) or willing to continue gonadotropin-releasing hormone (GnRH) analog or antagonist (medical castration)
Serum testosterone \< 50 ng/dL
Progressive disease in the setting of medical or surgical castration (i.e., Castration-resistant Prostate Cancer [CRPC]) as assessed by the investigator and includes at least one of the following:
1. Evidence of progression as measured by PSA increase of ≥ 25% and an absolute increase of ≥ 2 ng/mL in \< 6 months from end of last therapy prior to enrollment and/or
2. Soft tissue disease progression as per (RECIST) and/or
3. Bone disease progression defined by two or more new lesions on bone scan
Bisphosphonate or denosumab therapy allowed provided dose has been stable for at least 4 weeks prior to Day 1 of treatment
Prior treatment:
1. Prior treatment for metastatic CRPC (mCRPC) must have included at least one line with a second-generation androgen inhibitor (e.g., abiraterone, enzalutamide, apalutamide, daralutamide)
2. Prior chemotherapy permitted when administered in the metastatic hormone-sensitive prostate cancer setting. In addition, up to one is allowed in the mCRPC setting.
3. Prior treatment with sipuleucel-T, radium-223, or other non-chemotherapy based treatments for mCRPC (e.g., olaparib, pembrolizumab) is allowed.
Recovery from recent surgery, radiotherapy, chemotherapy or other anti-cancer treatment to baseline or ≤ Grade 1 (other than alopecia)
Demonstrate adequate organ function as defined in the table below; all Screening labs obtained within 28 days prior to Day 1 of treatment.
Patients who have not undergone a bilateral orchiectomy and have a female partner of must use an adequate barrier method of during study treatment and for 90 days after receiving the last dose of CPI-1205
Willing to provide access to for research purposes
Ability to swallow and retain oral medications
Ability to understand and willingness to sign an IRB approved written form (ICF) and authorization permitting release of personal health information including genetic testing relevant to cancer.
Able to comply with study visit schedule and assessments

Exclusion Criteria for Phase 1b Dose Escalation

Patients who meet any of the following criteria will not be enrolled in the study:

Known symptomatic
Treatment with any of the following for prostate cancer within the indicated timeframe prior to Day 1 of treatment
1. First generation: AR antagonists (e.g., bicalutamide, nilutamide, flutamide) within 4 weeks
2. 5 alpha reductase inhibitors, ketoconazole, estrogens (including diethylstilbesterol [DES]), or progesterones within 2 weeks
3. Chemotherapy within 3 weeks
4. Biologic therapy within 4 weeks
5. therapy within 3 weeks (or within a time interval less than at least 5 half-lives of the investigational agent [if known], whichever is longer).
6. Immunotherapy within 4 weeks
7. Radionuclide therapy within 4 weeks
Radiation therapy for the treatment of metastasis within 1 week prior to Day 1 of treatment
Herbal products that may decrease PSA levels within 4 weeks prior to day 1 of treatment
Systemic greater than 10 mg of prednisone/prednisolone per day within 4 weeks prior to day 1 of treatment
Major surgery within 4 weeks prior to Day 1 of treatment
Planned palliative procedures for alleviation of bone pain such as radiation therapy or surgery
Structurally unstable bone lesions concerning for impending fracture
cardiovascular disease including:
1. Myocardial infarction (MI)/Stroke within 6 months prior to Day 1 of treatment
2. Uncontrolled angina within 3 months
3. Congestive heart failure (CHF) with (NYHA) Class 3 or 4
4. History of clinically significant ventricular arrhythmias (e.g., ventricular tachycardia, ventricular fibrillation, torsades de pointes)
5. Uncontrolled hypertension (systolic blood pressure (BP) > 170 mmHg or diastolic BP > 105 mmHg at screening) despite 2 concomitant antihypertensive therapies
6. corrected by the Fridericia correction formula (QTcF) > 500 msec on the screening
Active or symptomatic viral hepatitis or chronic liver disease
History of unresolved adrenal dysfunction
GI disorder that negatively affects absorption
Required treatment with one of the prohibited concomitant medications;
Achlorhydria, either documented or suspected on the basis of an associated disease (e.g., pernicious anemia, atrophic gastritis, or certain gastric surgical procedures)
History of seizure, underlying brain injury with loss of consciousness, within 12 months prior to Day 1 of treatment, cerebral vascular accident or brain arteriovenous malformation
Known additional that is active and/or progressive requiring treatment; exceptions include basal cell or squamous cell skin cancer, in situ bladder cancer, or other cancer for which the patient has been disease-free for at least two years
Any other concurrent severe and/or uncontrolled concomitant medical condition that could compromise participation in the study (e.g., clinically significant pulmonary disease, clinically significant psychiatric or neurological disorder, active or uncontrolled infection)
Patient unwilling or unable to comply with this study protocol

PHASE 1b: HEAVILY PRETREATED EXPANSION COHORT (HPEC)

Inclusion Criteria for Phase 1b HPEC

Patients must meet all the following criteria to be enrolled in this study:

Age ≥ 18 years
ECOG Performance Status 0-1
Life expectancy of at least 12 weeks
Histologically or cytologically confirmed adenocarcinoma of the prostate (pure small cell carcinoma excluded)
Documented metastatic disease
At least 1 measurable lymph node per Prostate Cancer Clinical Trials Working Group 3 (PCWG3)
Must have undergone bilateral orchiectomy (surgical castration) or willing to continue GnRH analog or antagonist (medical castration)
Serum testosterone \< 50 ng/dL
Progressive disease in the setting of medical or surgical castration (i.e., CRPC) as assessed by the investigator and that includes at least 1 of the following:
1. Evidence of progression as measured by PSA defined as: PSA at least 2 ng/mL (or PSA at least 1 ng/mL if PSA progression is the only manifestation of progressive disease) and rising PSA by at least 2 consecutive measurements a minimum of 1-week apart and/or
2. Soft tissue disease progression as per RECIST 1.1 and/or
3. Bone disease progression defined by two or more new lesions on bone scan
Prior treatment:
1. Only 1 prior line of a second-generation androgen inhibitor from a different class than the one chosen for the applicable phase 2 study (the 2 classes are CYP17 inhibitors [e.g., abiraterone, orteronel] and AR inhibitors [e.g., enzalutamide, apalutamide]). Patient must have progressed after ≥ 24 weeks of treatment with this second generation angrogen inhibitor.
2. The last second-generation androgen inhibitor treatment received must not be from the same class as that incorporated in the applicable HPEC; i.e., if the HPEC incorporates enzalutamide, the last second generation androgen inhibitor therapy cannot be enzalutamide, apalutamide, etc.
3. Prior chemotherapy for mCRPC must have included at least 1 and no more than 2 prior lines of taxane-based chemotherapy administered in the metastatic hormone-sensitive prostate cancer setting is allowed
4. Prior treatment with sipuleucel-T, radium-223, or other non-chemotherapy-based treatments for mCRPC (e.g., olaparib, pembrolizumab, nivolumab) is allowed.
Recovery from recent surgery, radiotherapy, chemotherapy or other anti-cancer treatment to baseline or ≤ Grade 1 (other than alopecia)
Demonstrate adequate organ function as defined in the table below; all Screening labs to be obtained within 28 days prior to Day 1 of treatment
Patients who had not undergone a bilateral orchiectomy and have a female partner of childbearing potential must use an adequate barrier method of contraception during study treatment and for 90 days after receiving the last dose of CPI-1205
Willing to provide access to archival tumor tissue for research purposes
Ability to swallow and retain oral medications
Ability to understand and willingness to sign an IRB approved written ICF and authorization permitting release of personal health information including genetic testing relevant to cancer.
Able to comply with study visit schedule and assessments

Exclusion Criteria for Phase 1b HPEC

Patients meeting any of the following criteria will not be enrolled in the study:

Known symptomatic brain metastases
Treatment with any of the following for prostate cancer within the indicated timeframe prior to Day 1 of treatment
1. First-generation: AR antagonists (e.g., bicalutamide, nilutamide, flutamide) within 4 weeks
2. 5-alpha reductase inhibitors, ketoconazole, estrogens (including DES), or progesterones within 2 weeks
3. Chemotherapy within 3 weeks
4. Biologic therapy within 4 weeks
5. Investigational therapy within 3 weeks (or within a time interval less than at least 5 half-lives of the investigational agent [if known], whichever is longer).
6. Immunotherapy within 4 weeks
7. Radionuclide therapy within 4 weeks
Radiation therapy for the treatment of metastasis within 1 week prior to Day 1 of treatment
Herbal products that may decrease PSA levels within 4 weeks prior to Day 1 of treatment
Systemic steroids greater than 10 mg of prednisone/prednisolone per day within 4 weeks prior to Day 1 of treatment
Major surgery within 4 weeks prior to Day 1 of treatment
Structurally unstable bone lesions concerning for impending fracture
Clinically significant cardiovascular disease including:
1. MI/Stroke within 6 months prior to Day 1 of treatment
2. Uncontrolled angina within 3 months
3. CHF with NYHA Class 3 or 4
4. History of clinically significant ventricular arrhythmias (e.g., ventricular tachycardia, ventricular fibrillation, torsades de pointes)
5. Uncontrolled hypertension (systolic BP > 170 mmHg or diastolic BP > 105 mmHg at screening) despite two concomitant antihypertensive therapies
6. QTcF >500 msec on the screening ECG
Active or symptomatic viral hepatitis or chronic liver disease
History of unresolved adrenal dysfunction
GI disorder that negatively affects absorption
Required treatment with one of the prohibited concomitant medications
Achlorhydria, either documented or suspected on the basis of an associated disease (e.g., pernicious anemia, atrophic gastritis, or certain gastric surgical procedures)
History of seizure, underlying brain injury with loss of consciousness, transient ischemic attack within 12 months prior to day 1 of treatment, cerebral vascular accident or brain arteriovenous malformation
Known additional malignancy that is active and/or progressive requiring treatment; exceptions include basal cell or squamous cell skin cancer, in situ bladder cancer, or other cancer for which the patient has been disease-free for at least 2 years
Any other concurrent severe and/or uncontrolled concomitant medical condition that could compromise participation in the study (e.g., clinically significant pulmonary disease, clinically significant psychiatric or neurological disorder, active or uncontrolled infection)
Patient unwilling or unable to comply with this study protocol

PHASE 2

Phase 2 Inclusion Criteria

Patients must meet all of the following criteria to be enrolled in this study:

Age ≥ 18 years
ECOG Performance Status 0-1
Life expectancy of at least 12 weeks
Histologically or cytologically confirmed adenocarcinoma of the prostate (pure small cell carcinoma excluded)
Documented metastatic disease
Must have undergone bilateral orchiectomy (surgical castration) or willing to continue GnRH analog or antagonist (medical castration).
Serum testosterone \<5 0 ng/dL
Progressive disease in the setting of medical or surgical castration (i.e., CRPC) as assessed by the investigator and that includes at least 1 of the following:
1. Evidence of progression as measured by PSA defined as: PSA greater than or equal to 2 ng/mL (or PSA greater than or equal to 1 ng/mL if PSA progression is the only manifestation of progressive disease) and rising PSA by at least 2 consecutive measurements a minimum of 1-week apart and/or
2. Soft tissue disease progression as per RECIST 1.1 and/or
3. Bone disease progression defined by two or more new lesions on bone scan
Bisphosphonate or denosumab therapy allowed provided dose has been stable for ≥ 4 weeks prior to Day 1 of treatment.
Prior treatment:
1. Only one prior line of a second-generation androgen inhibitor from a different class than the one chosen for the applicable phase 2 study (the 2 classes are CYP17 inhibitors [e.g., abiraterone, orteronel] and AR inhibitors [e.g., enzalutamide, apalutamide]). Patient must have progressed after ≥ 24 weeks of treatment with this second generation angrogen inhibitor
2. No prior chemotherapy for mCRPC allowed; chemotherapy (including taxane-based) administered in the metastatic hormone-sensitive prostate cancer setting is allowed.
3. Prior treatment with sipuleucel-T, radium-223, or other non-chemotherapy based treatments approved by the US FDA for the treatment of mCRPC is allowed; prior treatment with non-chemotherapy based treatments that are not approved for the treatment of mCRPC (e.g., pembrolizumab, ipilimumab, olaparib) are not allowed.
Recovery from recent surgery, radiotherapy, chemotherapy or other anti-cancer treatment to baseline or ≤ Grade 1 (other than alopecia)
Demonstrate adequate organ function
Patients who have not undergone a bilateral orchiectomy and have a female partner of childbearing potential must use an adequate barrier method of contraception during study treatment and for 90 days after receiving the last dose of CPI-1205 (or partner drug in the control arm of any randomized phase 2 trial if the patient does not participate in the crossover).
Willing to provide access to archival tumor tissue for research purposes, if available
Ability to swallow and retain oral medications.
Ability to understand and willingness to sign an IRB approved written ICF and authorization permitting release of personal health information including genetic testing relevant to cancer.
Able to comply with study visit schedule and assessments

Phase 2 Exclusion Criteria

Patients who meet any of the following criteria will not be enrolled in the study:

Known symptomatic brain metastases
Treatment with any of the following for prostate cancer within the indicated timeframe prior to Day 1 of treatment
1. First-generation AR antagonists (e.g., bicalutamide, nilutamide, flutamide) within 4 weeks
2. 5-alpha reductase inhibitors, ketoconazole, estrogens (including DES), or progesterones within 2 weeks
3. Chemotherapy within 3 weeks
4. Biologic therapy within 4 weeks
5. Radionuclide therapy within 4 weeks
Radiation therapy for the treatment of metastasis within 1 week prior to Day 1 of treatment
Herbal products that may decrease PSA levels within 4 weeks prior to Day 1 of treatment
Systemic steroids > 10 mg of prednisone/prednisolone per day within 4 weeks prior to Day 1 of treatment
Major surgery within 4 weeks prior to Day 1 of treatment
Planned palliative procedures for alleviation of bone pain such as radiation therapy or surgery
Structurally unstable bone lesions concerning for impending fracture
Clinically significant cardiovascular disease including:
1. MI/stroke within 6 months prior to day 1 of treatment
2. Unstable angina within 3 months
3. CHF with NYHA Class 3 or 4
4. History of clinically significant ventricular arrhythmias (e.g., ventricular tachycardia, ventricular fibrillation, torsades de pointes)
5. Uncontrolled hypertension (systolic BP > 170 mmHg or diastolic BP > 105 mmHg at screening) despite two concomitant antihypertensive therapies
6. QTcF > 500 msec on the screening ECG
Active or symptomatic viral hepatitis or chronic liver disease
History of unresolved adrenal dysfunction
GI disorder that negatively affects absorption
Required treatment with one of the prohibited concomitant medications
Achlorhydria, either documented or suspected on the basis of an associated disease (e.g., pernicious anemia, atrophic gastritis, or certain gastric surgical procedures)
History of seizure, underlying brain injury with loss of consciousness, transient ischemic attack within 12 months prior to Day 1 of treatment, cerebral vascular accident or brain arteriovenous malformation
Known additional malignancy that is active and/or progressive requiring treatment; exceptions include basal cell or squamous cell skin cancer, in situ bladder cancer, or other cancer for which the patient has been disease-free for at least two years
Any other concurrent severe and/or uncontrolled concomitant medical condition that could compromise participation in the study (e.g., clinically significant pulmonary disease, clinically significant psychiatric or neurological disorder, active or uncontrolled infection)
Patient unwilling or unable to comply with this study protocol

Terms in these criteria, in plain language(19)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

ECOG performance status

A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.

0: Fully active, no restrictions.
1: Limited in strenuous activity, but walking and able to do light work, such as housework or office work.
2: Walking and able to look after yourself, but unable to work; up and about more than half of waking hours.
3: Able to look after yourself only in part; in bed or a chair more than half of waking hours.
4: Unable to look after yourself at all; in bed or a chair all day.

Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.

Life expectancy

The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.

Histologically or cytologically confirmed

The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).

Your pathology report is the document that shows this.

Metastases

Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.

RECIST

The standard rules for measuring tumours on CT or MRI scans, to tell whether a cancer is shrinking, stable or growing during treatment.

“Measurable disease per RECIST 1.1” usually means at least one tumour 10 mm or more at its longest on a CT scan, or a lymph node 15 mm or more across its short axis.

Line of therapy

A line of therapy is one course of treatment, which may combine several drugs. First-line is the first course given; second-line follows when that stops working or is not tolerated.

“Two prior lines” means two courses that count separately under the study’s rules — not simply two drugs. Ask the study team if you are unsure how yours are counted.

Childbearing potential

Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).

Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

Biopsy and archival tissue

A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.

Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Brain metastases

Cancer deposits in the brain from a cancer that started elsewhere in the body (CNS metastases include the spinal cord).

Studies differ: some leave out any brain metastases, some accept ones treated and stable for some weeks. Check what this study allows.

Investigational drug or device

A drug or device being studied in a clinical trial.

It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.

Corticosteroids (steroids)

Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.

Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.

Clinically significant

Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.

NYHA class (heart failure)

The New York Heart Association’s four classes of how much heart failure limits physical activity.

I: No limits: ordinary activity causes no undue tiredness or breathlessness.
II: Slight limits: comfortable at rest, ordinary activity causes symptoms.
III: Marked limits: comfortable at rest, less than ordinary activity causes symptoms.
IV: Symptoms even at rest; any activity makes them worse.

Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.

QT and QTc

On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.

The study may name a correction formula and a limit in milliseconds, often around 450–480.

ECG (electrocardiogram)

A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.

TIA (transient ischaemic attack)

A “mini-stroke”: temporary stroke-like symptoms caused by reduced blood flow to part of the brain, spinal cord or eye, without signs of a new stroke on a scan.

Stroke symptoms need emergency care at once, even if they go away.

Cancer (malignancy)

Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.

Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.

Study design

Phase: Phase 1 / Phase 2
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel assignment
Masking: None (open label)
Enrollment: 175 participants (actual)

Study arms

Experimental
Phase 1b Dose Escalation: CPI-1205 400 mg BID + Cobi + Enza
CPI-1205 400 mg BID in combination with Cobicistat 150 mg PO BID and Enzalutamide 160 mg PO QD (28-day cycles)
Drug: CPI-1205 · Drug: Cobicistat · Drug: Enzalutamide
Experimental
Phase 1b Dose Escalation: CPI-1205 400 mg BID + Cobi+ Abi/Pred
CPI-1205 400 mg BID in combination with Cobicistat 150 mg PO BID and Abiraterone 100 mg PO QD and Prednisone 5 mg PO BID (28-day cycle)
Drug: CPI-1205 · Drug: Cobicistat · Drug: Abiraterone · Drug: Prednisone
Experimental
Phase 1b Dose Escalation: CPI-1205 800 mg TID + Enza
CPI-1205 800 mg TID in combination with Enzalutamide 160 mg PO QD (28-day cycle)
Drug: CPI-1205 · Drug: Enzalutamide
Experimental
Phase 1b Dose Escalation: CPI-1205 800 mg TID + Abi/Pred
CPI-1205 800 mg TID in combination with Abiraterone 100 mg PO QD and Prednisone 5 mg PO BID (28-day cycle)
Drug: CPI-1205 · Drug: Abiraterone · Drug: Prednisone
Experimental
Phase 1b HPEC: CPI-1205 800 mg TID + Enza
CPI-1205 800 mg TID highly pretreated expansion cohort (HEPC) in combination with Enzalutamide 160 mg PO QD (28-day cycles)
Drug: CPI-1205 · Drug: Enzalutamide
Active comparator
Phase 2 Randomized Controlled Group: Enza
Drug: Enzalutamide 160mg PO QD (28-day cycles)
Drug: Enzalutamide
Experimental
Phase 2 Randomized at RP2D: CPI-1205 800 mg TID + Enza
CPI-1205 (at Recommended Phase 2 Dose \[RP2D\]) in combination with Drug: Enzalutamide 160 mg PO QD
Drug: CPI-1205 · Drug: Enzalutamide
Experimental
Phase 2 Single Arm at RP2D: CPI-1205 800 mg TID + Abi/Pred
CPI-1205 at 800 mg TID (Recommended Phase 2 Dose \[RP2D\]) 800 mg TID in combination with Abiraterone 1000 mg PO QD and Prednisone 5 mg PO BID (28-day cycles)
Drug: CPI-1205 · Drug: Abiraterone · Drug: Prednisone

Interventions

DrugCPI-1205
CPI-1205: Either 400 mg BID or 800 mg TID during Phase 1 dose-escalation and RP2D, 800 mg TID, for Phase 2
DrugCobicistat
Cobicistat 150 mg PO BID
DrugEnzalutamide
Enzalutamide 160mg PO QD
DrugAbiraterone
Abiraterone 1000mg PO QD
DrugPrednisone
Prednisone 5mg PO BID

What researchers measure

Primary outcomes

Efficacy: Best Objective Response Rate Percent by Treatment Group
Best overall response rate (%) defined as complete response (CR) + partial response (PR) divided by the total number of subjects as assessed by Investigator. The response assessment was performed per Prostate Cancer Working Group 3 (PCWG3) based on modifications of the RECIST 1.1 criteria. Per RECIST 1.1, a CR was assessed when all target lesions disappeared (any pathological lymph node must have reduction in short axis to \<10 mm) in the post-baseline scan. A PR was assessed when there was at least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters.
Time frame: Up to 2 years [or until disease progression or unacceptable toxicity]
Efficacy: Percentage (%) of Subjects With PSA30
The number of subjects who had a confirmed reduction of 30% of prostate-specific antigen (PSA30) from baseline
Time frame: 2 years [or until progressive disease or unacceptable toxicity]
Efficacy: Percentage (%) of Subjects With PSA50
The number of subjects who had a confirmed reduction of 50% of prostate-specific antigen (PSA50) from baseline
Time frame: 2 years [or until progressive disease or unacceptable toxicity]
Efficacy: Composite Response Rate (%) for Phase 2 Randomized and Phase 2 Single-arm Treatment Groups
Subjects who had a circulating tumor cell of 30% (CTC 30%) or an objective response rate divided by the number of evaluable subjects
Time frame: Up to 2 years [or until progressive disease or unacceptable toxicity]

Secondary outcomes

Efficacy: Best Responses by Treatment Group
Best overall response defined as complete response (CR), partial response (PR); stable disease (SD); progressive disease (PD); and unknown/missing for the Phase 1b dose-escalation group, the Phase 1b HPEC group, the Phase 2 randomized groups, crossover group and the Phase 2 single-arm group. Assessed by Investigator
Time frame: Up to 2 years [or until disease progression or unacceptable toxicity]
Safety: Number of Participants With Treatment-emergent AEs Leading to Treatment Discontinuation
Treatment-emergent Adverse events (AEs) leading to subjects withdrawing from treatment
Time frame: Up to 2 years [or until clinical progression, radiographic disease progression, or until unacceptable toxicity]

Results

Posted Oct 29, 2025

Participant flow

Participant flow — Overall Study
Milestone	Phase 1b Dose Escalation: CPI-1205 400 mg BID + Cobi + Enza	Phase 1b Dose Escalation: CPI-1205 400 mg BID + Cobi + Abi/Pred	Phase 1b Dose Escalation: CPI-1205 800 mg TID + Enza	Phase 1b Dose Escalation: CPI-1205 800 mg TID + Abi/Pred	Phase 1b HPEC: CPI-1205 800 mg TID Heavily Pre-treated Expansion Cohort + Enza	Phase 2 Randomized Controlled: Enza	Phase 2 Randomized Experimental: CPI-1205 at RP2D + Enza	Phase 2 Single Arm: CPI-1205 (at RP2D) +Abi/Pred
Started	7	8	9	13	32	35	39	32
Phase 2: crossover from enza to cpi-1205 800mg tid + enza	0	0	0	0	0	12	0	0
Safety analysis set (saf)	7	8	9	12	31	35	39	32
Full analysis set (fas)	7	8	9	12	31	35	39	32
Efficacy analysis set (eas)	5	7	9	11	25	35	38	28
Completed	0	0	0	0	0	0	0	0
Not completed	7	8	9	13	32	35	39	32

Outcome measures

PrimaryEfficacy: Best Objective Response Rate Percent by Treatment Group

Best overall response rate (%) defined as complete response (CR) + partial response (PR) divided by the total number of subjects as assessed by Investigator. The response assessment was performed per Prostate Cancer Working Group 3 (PCWG3) based on modifications of the RECIST 1.1 criteria. Per RECIST 1.1, a CR was assessed when all target lesions disappeared (any pathological lymph node must have reduction in short axis to \<10 mm) in the post-baseline scan. A PR was assessed when there was at least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters.

Time frame:: Up to 2 years [or until disease progression or unacceptable toxicity]
Reported as:: Number · Percent (%) of subjects

Efficacy: Best Objective Response Rate Percent by Treatment Group
Percent (%) of subjects	Phase 1b Dose Escalation: CPI-1205 400 mg BID + Cobi + Enza	Phase 1b Dose Escalation: CPI-1205 400 mg BID + Cobi + Abi/Pred	Phase 1b Dose Escalation: CPI-1205 800 mg TID + Enza	Phase 1b Dose Escalation: CPI-1205 800 mg TID +Abi/Pred	Phase 1b HPEC: Heavily Pretreated Expansion Cohort CPI-1205 800 mg TID + Enza	Phase 2 Randomized Controlled: Enza	Phase 2 Randomized Experimental: CPI-1205 at RP2D (800 mg TID) + Enza	Phase 2 Randomized Crossover Period	Phase 2 Single Arm CPI-1205 at RP2D (800 mg TID) + Abi/Pred
Efficacy: Best Objective Response Rate Percent by Treatment Group	0 (0 to 52.18)	0 (0 to 40.96)	0 (0 to 33.63)	0 (0 to 28.49)	8.00 (0.98 to 26.03)	5.71 (0.70 to 19.16)	7.89 (1.66 to 21.38)	0 (0 to 26.46)	0 (0 to 12.34)

PrimaryEfficacy: Percentage (%) of Subjects With PSA30

The number of subjects who had a confirmed reduction of 30% of prostate-specific antigen (PSA30) from baseline

Time frame:: 2 years [or until progressive disease or unacceptable toxicity]
Reported as:: Count of participants · Participants

Efficacy: Percentage (%) of Subjects With PSA30
Participants	Phase 1b Dose Escalation: CPI-1205 400mg BID +Cobi+Enza	Phase 1b Dose Escalation: CPI-1205 400mg BID +Cobi+Abi/Pred	Phase 1b Dose Escalation: CPI-1205 800mg TID +Enza	Phase 1b Dose Escalation: CPI-1205 800mg TID +Abi/Pred	Phase 1b HPEC [Heavily Pre-treated Expansion Cohort] CPI-1205 800mg TID +Enza	Phase 2 Randomized Enza Contro	Phase 2 Randomized Combination With Enza	Phase 2 Randomized Crossover Period	Phase 2 Single Arm CPI-1205 +Abi/Pred
Efficacy: Percentage (%) of Subjects With PSA30	1	1	2	1	7	7	12	1	4

PrimaryEfficacy: Percentage (%) of Subjects With PSA50

The number of subjects who had a confirmed reduction of 50% of prostate-specific antigen (PSA50) from baseline

Time frame:: 2 years [or until progressive disease or unacceptable toxicity]
Reported as:: Count of participants · Participants

Efficacy: Percentage (%) of Subjects With PSA50
Participants	Phase 1b Dose Escalation: CPI-1205 400mg BID +Cobi+Enza	Phase 1b Dose Escalation: CPI-1205 400mg BID +Cobi+Abi/Pred	Phase 1b Dose Escalation: CPI-1205 800mg TID +Enza	Phase 1b Dose Escalation: CPI-1205 800mg TID +Abi/Pred	Phase 1b HPEC [Heavily Pre-treated Expansion Cohort] CPI-1205 800mg TID +Enza	Phase 2 Randomized Enza Contro	Phase 2 Randomized Combination With Enza	Phase 2 Randomized Crossover Period	Phase 2 Single Arm CPI-1205 +Abi/Pred
Efficacy: Percentage (%) of Subjects With PSA50	1	1	1	1	4	5	10	0	2

PrimaryEfficacy: Composite Response Rate (%) for Phase 2 Randomized and Phase 2 Single-arm Treatment Groups

Subjects who had a circulating tumor cell of 30% (CTC 30%) or an objective response rate divided by the number of evaluable subjects

Time frame:: Up to 2 years [or until progressive disease or unacceptable toxicity]
Reported as:: Number · Percent (%) of subjects

Efficacy: Composite Response Rate (%) for Phase 2 Randomized and Phase 2 Single-arm Treatment Groups
Percent (%) of subjects	Phase 2 Randomized Enza Contro	Phase 2 Randomized Combination With Enza	Phase 2 Randomized Crossover Period	Phase 2 Single Arm CPI-1205 +Abi/Pred
Efficacy: Composite Response Rate (%) for Phase 2 Randomized and Phase 2 Single-arm Treatment Groups	17.1 (6.6 to 33.6)	31.4 (16.9 to 49.3)	0 (0.0 to 30.8)	21.4 (8.3 to 41.0)

SecondaryEfficacy: Best Responses by Treatment Group

Best overall response defined as complete response (CR), partial response (PR); stable disease (SD); progressive disease (PD); and unknown/missing for the Phase 1b dose-escalation group, the Phase 1b HPEC group, the Phase 2 randomized groups, crossover group and the Phase 2 single-arm group. Assessed by Investigator

Time frame:: Up to 2 years [or until disease progression or unacceptable toxicity]
Reported as:: Count of participants · Participants

Efficacy: Best Responses by Treatment Group
Participants	Phase 1b Dose Escalation: CPI-1205 400mg BID +Cobi+Enza	Phase 1b Dose Escalation: CPI-1205 400mg BID +Cobi+Abi/Pred	Phase 1b Dose Escalation: CPI-1205 800mg TID +Enza	Phase 1b Dose Escalation: CPI-1205 800mg TID +Abi/Pred	Phase 1b HPEC [Heavily Pre-treated Expansion Cohort] CPI-1205 800mg TID +Enza	Phase 2 Randomized Enza Contro	Phase 2 Randomized Combination With Enza	Phase 2 Randomized Crossover Period	Phase 2 Single Arm CPI-1205 +Abi/Pred
CR	0	0	0	0	0	0	0	0	0
PR	0	0	0	0	2	2	3	0	0
SD	2	3	5	7	10	23	24	5	21
PD	3	3	4	1	10	9	7	0	5
Not evaluable, unknown, or missing	0	1	0	3	3	1	4	7	2

SecondarySafety: Number of Participants With Treatment-emergent AEs Leading to Treatment Discontinuation

Treatment-emergent Adverse events (AEs) leading to subjects withdrawing from treatment

Time frame:: Up to 2 years [or until clinical progression, radiographic disease progression, or until unacceptable toxicity]
Reported as:: Count of participants · Participants

Safety: Number of Participants With Treatment-emergent AEs Leading to Treatment Discontinuation
Participants	Phase 1b Dose Escalation: CPI-1205 400mg BID +Cobi+Enza	Phase 1b Dose Escalation: CPI-1205 400mg BID +Cobi+Abi/Pred	Phase 1b Dose Escalation: CPI-1205 800mg TID +Enza	Phase 1b Dose Escalation: CPI-1205 800mg TID +Abi/Pred	Phase 1b HPEC [Heavily Pre-treated Expansion Cohort] CPI-1205 800mg TID +Enza	Phase 2 Randomized Enza Contro	Phase 2 Randomized Combination With Enza	Phase 2 Randomized Crossover Period	Phase 2 Single Arm CPI-1205 +Abi/Pred
Safety: Number of Participants With Treatment-emergent AEs Leading to Treatment Discontinuation	0	4	0	2	4	2	4	0	2

Adverse events

Collected over Up to 2 years [or until progressive disease or unacceptable toxicity]. Non-serious events are listed at a 5% frequency threshold.

Adverse event summary by group
Group	Deaths	Serious	Other
Phase 1b Dose Escalation: CPI-1205 400 mg BID + Cobi + Enza	1/7 (14.3%)	2/7 (28.6%)	7/7 (100%)
Phase 1b Dose Escalation: CPI-1205 400 mg BID + Cobi + Abi/Pred	2/8 (25%)	3/8 (37.5%)	8/8 (100%)
Phase 1b Dose Escalation: CPI-1205 800 mg TID + Enza	1/9 (11.1%)	2/9 (22.2%)	9/9 (100%)
Phase 1b Dose Escalation: CPI-1205 800 mg TID + Abi/Pred	1/12 (8.3%)	1/12 (8.3%)	12/12 (100%)
Phase 1b HPEC: CPI-1205 800 mg TID Heavily Pretreated Expansion Cohort + Enza	17/31 (54.8%)	11/31 (35.5%)	31/31 (100%)
Phase 2 Randomized Control: Enza	10/35 (28.6%)	8/35 (22.9%)	33/35 (94.3%)
Phase 2 Randomized Experimental: CPI-1205 at RP2D + Enza	7/39 (17.9%)	5/39 (12.8%)	38/39 (97.4%)
Phase 2 Randomized Crossover Period	4/12 (33.3%)	0/12 (0%)	11/12 (91.7%)
Phase 2 Single Arm: CPI-1205 (at RP2D) + Abi/Pred	9/32 (28.1%)	1/32 (3.1%)	30/32 (93.8%)

Most frequent serious events

Showing 10 of 38

Most frequent serious events
Event	Phase 1b Dose Escalation: CPI-1205 400 mg BID + Cobi + Enza	Phase 1b Dose Escalation: CPI-1205 400 mg BID + Cobi + Abi/Pred	Phase 1b Dose Escalation: CPI-1205 800 mg TID + Enza	Phase 1b Dose Escalation: CPI-1205 800 mg TID + Abi/Pred	Phase 1b HPEC: CPI-1205 800 mg TID Heavily Pretreated Expansion Cohort + Enza	Phase 2 Randomized Control: Enza	Phase 2 Randomized Experimental: CPI-1205 at RP2D + Enza	Phase 2 Randomized Crossover Period	Phase 2 Single Arm: CPI-1205 (at RP2D) + Abi/Pred
PainGeneral disorders	1/7	0/8	0/9	0/12	0/31	0/35	0/39	—	0/32
Acute coronary syndromeCardiac disorders	1/7	0/8	0/9	0/12	0/31	0/35	0/39	—	0/32
Neoplasm malignantNeoplasms benign, malignant and unspecified (incl cysts and polyps)	1/7	0/8	0/9	0/12	0/31	0/35	0/39	—	0/32
Cerebrovascular accidentNervous system disorders	1/7	0/8	0/9	0/12	1/31	0/35	0/39	—	0/32
Pelvic massGeneral disorders	0/7	1/8	0/9	0/12	0/31	0/35	0/39	—	0/32
PneumoniaInfections and infestations	0/7	1/8	0/9	0/12	0/31	1/35	0/39	—	0/32
Urinary tract infectionInfections and infestations	0/7	1/8	0/9	0/12	1/31	0/35	0/39	—	0/32
Acute respiratory failureRespiratory, thoracic and mediastinal disorders	0/7	1/8	0/9	0/12	0/31	0/35	0/39	—	0/32
HypotensionVascular disorders	0/7	1/8	0/9	0/12	0/31	0/35	0/39	—	0/32
Cardiac failure congestiveCardiac disorders	0/7	0/8	1/9	0/12	0/31	0/35	0/39	—	0/32

Most frequent other events

Showing 10 of 27

Most frequent other events
Event	Phase 1b Dose Escalation: CPI-1205 400 mg BID + Cobi + Enza	Phase 1b Dose Escalation: CPI-1205 400 mg BID + Cobi + Abi/Pred	Phase 1b Dose Escalation: CPI-1205 800 mg TID + Enza	Phase 1b Dose Escalation: CPI-1205 800 mg TID + Abi/Pred	Phase 1b HPEC: CPI-1205 800 mg TID Heavily Pretreated Expansion Cohort + Enza	Phase 2 Randomized Control: Enza	Phase 2 Randomized Experimental: CPI-1205 at RP2D + Enza	Phase 2 Randomized Crossover Period	Phase 2 Single Arm: CPI-1205 (at RP2D) + Abi/Pred
FatigueGeneral disorders	3/7	3/8	7/9	4/12	12/31	18/35	23/39	6/12	6/32
DiarrhoeaGastrointestinal disorders	2/7	2/8	6/9	5/12	14/31	6/35	21/39	8/12	18/32
ArthralgiaMusculoskeletal and connective tissue disorders	4/7	0/8	1/9	3/12	6/31	9/35	3/39	4/12	2/32
NauseaGastrointestinal disorders	0/7	3/8	5/9	4/12	15/31	6/35	12/39	4/12	9/32
Back painMusculoskeletal and connective tissue disorders	3/7	1/8	4/9	2/12	5/31	5/35	5/39	2/12	3/32
Decreased appetiteMetabolism and nutrition disorders	2/7	3/8	2/9	3/12	9/31	5/35	9/39	1/12	1/32
Pain in extremityMusculoskeletal and connective tissue disorders	1/7	1/8	2/9	4/12	0/31	1/35	7/39	1/12	6/32
AnemiaBlood and lymphatic system disorders	0/7	1/8	1/9	3/12	5/31	5/35	4/39	4/12	6/32
Peripheral edemaGeneral disorders	2/7	0/8	2/9	2/12	2/31	2/35	0/39	1/12	1/32
ConstipationGastrointestinal disorders	1/7	2/8	1/9	0/12	7/31	3/35	4/39	2/12	0/32

Baseline characteristics

Full Analysis Set (FAS)

Age, Categorical
Age, Categorical(Participants)	Phase 1b Dose Escalation: CPI-1205 400 mg BID +Cobi + Enza	Phase 1b Dose Escalation: CPI-1205 400 mg BID + Cobi + Abi/Pred	Phase 1b Dose Escalation: CPI-1205 800 mg TID + Enza	Phase 1b Dose Escalation: CPI-1205 800 mg TID + Abi/Pred	Phase 1b HPEC: CPI-1205 800 mg TID Heavily Pretreated Expansion Cohort + Enza	Phase 2 Randomized Controlled: Enza	Phase 2 Randomized Experimental: CPI-1205 at RP2D + Enza	Phase 2 Single Arm: CPI-1205 at RP2D + Abi/Pred	Total
<=18 years	0	0	0	0	0	0	0	0	0
Between 18 and 65 years	2	0	3	2	9	9	16	9	50
>=65 years	5	8	6	10	22	26	23	23	123

Sex: Female, Male
Sex: Female, Male(Participants)	Phase 1b Dose Escalation: CPI-1205 400 mg BID +Cobi + Enza	Phase 1b Dose Escalation: CPI-1205 400 mg BID + Cobi + Abi/Pred	Phase 1b Dose Escalation: CPI-1205 800 mg TID + Enza	Phase 1b Dose Escalation: CPI-1205 800 mg TID + Abi/Pred	Phase 1b HPEC: CPI-1205 800 mg TID Heavily Pretreated Expansion Cohort + Enza	Phase 2 Randomized Controlled: Enza	Phase 2 Randomized Experimental: CPI-1205 at RP2D + Enza	Phase 2 Single Arm: CPI-1205 at RP2D + Abi/Pred	Total
Female	0	0	0	0	0	0	0	0	0
Male	7	8	9	12	31	35	39	32	173

Race (NIH/OMB)
Race (NIH/OMB)(Participants)	Phase 1b Dose Escalation: CPI-1205 400 mg BID +Cobi + Enza	Phase 1b Dose Escalation: CPI-1205 400 mg BID + Cobi + Abi/Pred	Phase 1b Dose Escalation: CPI-1205 800 mg TID + Enza	Phase 1b Dose Escalation: CPI-1205 800 mg TID + Abi/Pred	Phase 1b HPEC: CPI-1205 800 mg TID Heavily Pretreated Expansion Cohort + Enza	Phase 2 Randomized Controlled: Enza	Phase 2 Randomized Experimental: CPI-1205 at RP2D + Enza	Phase 2 Single Arm: CPI-1205 at RP2D + Abi/Pred	Total
American Indian or Alaska Native	0	0	0	0	0	0	0	0	0
Asian	0	0	0	0	0	0	1	1	2
Native Hawaiian or Other Pacific Islander	0	0	0	0	0	0	0	0	0
Black or African American	1	2	3	2	6	8	6	7	35
White	6	6	6	10	23	22	29	21	123
More than one race	0	0	0	0	0	0	0	0	0
Unknown or Not Reported	0	0	0	0	2	5	3	3	13

Prior cancer Immunotherapy
Prior cancer Immunotherapy(Participants)	Phase 1b Dose Escalation: CPI-1205 400 mg BID +Cobi + Enza	Phase 1b Dose Escalation: CPI-1205 400 mg BID + Cobi + Abi/Pred	Phase 1b Dose Escalation: CPI-1205 800 mg TID + Enza	Phase 1b Dose Escalation: CPI-1205 800 mg TID + Abi/Pred	Phase 1b HPEC: CPI-1205 800 mg TID Heavily Pretreated Expansion Cohort + Enza	Phase 2 Randomized Controlled: Enza	Phase 2 Randomized Experimental: CPI-1205 at RP2D + Enza	Phase 2 Single Arm: CPI-1205 at RP2D + Abi/Pred	Total
Yes	2	4	4	4	14	8	10	12	58
No	5	4	5	8	17	27	29	20	115

Prior cancer hormonal Therapy
Prior cancer hormonal Therapy(Participants)	Phase 1b Dose Escalation: CPI-1205 400 mg BID +Cobi + Enza	Phase 1b Dose Escalation: CPI-1205 400 mg BID + Cobi + Abi/Pred	Phase 1b Dose Escalation: CPI-1205 800 mg TID + Enza	Phase 1b Dose Escalation: CPI-1205 800 mg TID + Abi/Pred	Phase 1b HPEC: CPI-1205 800 mg TID Heavily Pretreated Expansion Cohort + Enza	Phase 2 Randomized Controlled: Enza	Phase 2 Randomized Experimental: CPI-1205 at RP2D + Enza	Phase 2 Single Arm: CPI-1205 at RP2D + Abi/Pred	Total
Yes	7	8	9	12	31	35	39	31	172
No	0	0	0	0	0	0	0	1	1

Prior cancer chemotherapy
Prior cancer chemotherapy(Participants)	Phase 1b Dose Escalation: CPI-1205 400 mg BID +Cobi + Enza	Phase 1b Dose Escalation: CPI-1205 400 mg BID + Cobi + Abi/Pred	Phase 1b Dose Escalation: CPI-1205 800 mg TID + Enza	Phase 1b Dose Escalation: CPI-1205 800 mg TID + Abi/Pred	Phase 1b HPEC: CPI-1205 800 mg TID Heavily Pretreated Expansion Cohort + Enza	Phase 2 Randomized Controlled: Enza	Phase 2 Randomized Experimental: CPI-1205 at RP2D + Enza	Phase 2 Single Arm: CPI-1205 at RP2D + Abi/Pred	Total
Yes	3	3	3	4	31	7	9	8	68
No	4	5	6	8	0	28	30	24	105

Prior radiation therapy
Prior radiation therapy(Participants)	Phase 1b Dose Escalation: CPI-1205 400 mg BID +Cobi + Enza	Phase 1b Dose Escalation: CPI-1205 400 mg BID + Cobi + Abi/Pred	Phase 1b Dose Escalation: CPI-1205 800 mg TID + Enza	Phase 1b Dose Escalation: CPI-1205 800 mg TID + Abi/Pred	Phase 1b HPEC: CPI-1205 800 mg TID Heavily Pretreated Expansion Cohort + Enza	Phase 2 Randomized Controlled: Enza	Phase 2 Randomized Experimental: CPI-1205 at RP2D + Enza	Phase 2 Single Arm: CPI-1205 at RP2D + Abi/Pred	Total
Yes	6	5	6	9	28	19	28	24	125
No	1	3	3	3	3	16	11	8	48

Study locations

41 sites

Alaska Urological Institute
Anchorage, Alaska 99503, United States
Beverly Hills Cancer Center (BHCC)
Beverly Hills, California 90211, United States
John Wayne Cancer Inst.
Duarte, California 91010, United States
UCLA
Los Angeles, California 90095, United States
Rocky Mountain Cancer Centers
Aurora, Colorado 80045, United States
University of Colorado Hospital - Anschutz Cancer Pavilion
Aurora, Colorado 80045, United States
University of Florida
Jacksonville, Florida 32209, United States
Mount Sinai Comprehensive Cancer Center
Miami, Florida 33140, United States
H. Lee Moffitt Cancer Center & Research Institute
Tampa, Florida 33612, United States
Rush University Medical Center
Chicago, Illinois 60612, United States
University of Illinois Hospital and Health Systems
Chicago, Illinois 60612, United States
Indiana University- Simon Cancer Center
Indianapolis, Indiana 46202, United States
Tulane University Health Sciences Center
New Orleans, Louisiana 70112, United States
University of Maryland
Baltimore, Maryland 21201, United States
John Hopkins Kimmel Cancer Center
Baltimore, Maryland 21205, United States
Maryland Oncology Hematology
Rockville, Maryland 20850, United States
Dana Farber Cancer Institute
Boston, Massachusetts 02115, United States
Henry Ford Health System
Detroit, Michigan 48202, United States
GU Research Network
Omaha, Nebraska 68130, United States
Comprehensive Cancer Centers of Nevada
Las Vegas, Nevada 89135, United States
New Mexico Cancer Center
Albuquerque, New Mexico 87106, United States
Roswell Park Comprehensive Cancer Center
Buffalo, New York 14263, United States
North Shore Hematology Oncology Associates
East Setauket, New York 11733, United States
NYU Langone Medical Center Laura and Isaac Permlutter Cancer Center
New York, New York 10016, United States
Icahn School of Medicine at Mt. Sinai
New York, New York 10029, United States
Eastchester Center for Cancer Care
The Bronx, New York 10469, United States
University of North Carolina-Chapel Hill
Chapel Hill, North Carolina 27599, United States
Levine Cancer Institute
Charlotte, North Carolina 28204, United States
Duke University Medical Center
Durham, North Carolina 22710, United States
Ohio State University - James Cancer Hospital and Solove Research Institute
Columbus, Ohio 43210, United States
Toledo Clinic Cancer Center
Toledo, Ohio 43623, United States
Williamette Valley Cancer Institute and Research Center
Eugene, Oregon 97401, United States
Compass Oncology - East
Tualatin, Oregon 97062, United States
St. Luke's University
Bethlehem, Pennsylvania 18015, United States
Gettysburg Cancer Center
Gettysburg, Pennsylvania 17331, United States
Greenville Hospital System, Institute for Translational Oncology Research
Greenville, South Carolina 29605, United States
Carolina Urologic Research Center
Myrtle Beach, South Carolina 29572, United States
Texas Oncology - Central Austin Cancer Center
Austin, Texas 78731, United States
Texas Oncology- Fort Worth
Fort Worth, Texas 76104, United States
Texas Oncology- Tyler
Tyler, Texas 75702, United States
Virginia Oncology Associates
Hampton, Virginia 23666, United States

References and documents

Study documents

Study protocol ↗ · Jul 26, 2018
Statistical analysis plan ↗ · Apr 13, 2021

PDFs hosted by the registry, ClinicalTrials.gov.

Updates

Tracking since Sep 25, 2026

No changes since tracking began. The registry record was last updated on Oct 29, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗

Registry details

Key details

Study ID: NCT03480646
Lead sponsor: Constellation Pharmaceuticals
Responsible party: Sponsor
First posted: Mar 29, 2018
Start date: Nov 15, 2017
Primary completion: Feb 3, 2021
Completion: Feb 3, 2021
Results posted: Oct 29, 2025
Last update: Oct 29, 2025

Oversight

Data monitoring committee: No
FDA-regulated drug: Yes
FDA-regulated device: No

View the source record on ClinicalTrials.gov ↗

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Studies of the drugs tested here: Lirametostat · Enzalutamide

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