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A Phase II Study of PX-866 in Patients With Recurrent or Metastatic Castration Resistant Prostate Cancer

A Phase II Study of PX-866 in Patients With Recurrent or Metastatic Castration Resistant Prostate Cancer

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01331083
Enrollment
68
Registered
2011-04-07
Start date
2011-09-09
Completion date
2015-11-27
Last updated
2023-08-22

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

Conditions

Prostate Cancer

Brief summary

The purpose of this study is to find out whether the new drug PX-866 will slow the growth of your prostate cancer. The investigators will also watch you carefully for any side effects that PX-866 might cause.

Detailed description

PX 866 is a new type of drug that inhibits a molecule related to cancer cell growth. While this molecule is also found in normal cells, it is much more active in some cancer cells, so inhibiting the molecule with PX-866 is hoped to slow the growth of cancer cells. Laboratory tests show that it may help slow the growth of prostate cancer in animals, but it is not known whether it will have the same effects in humans. PX-866 has been studied in some cancer patients to find out safe doses that can be given but it has not undergone study in prostate cancer. This study will be the first study of PX-866 in prostate cancer. Health Canada has not approved the sale or use of PX-866 to treat prostate cancer, although they have approved its use in this clinical trial.

Interventions

DRUGPX-866

PX-866: 8mg orally taken daily

Sponsors

Oncothyreon Canada Inc.
CollaboratorINDUSTRY
NCIC Clinical Trials Group
Lead SponsorNETWORK

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Eligibility

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

Inclusion criteria

* Patients must have a histological or cytological diagnosis of adenocarcinoma of the prostate. * All patients must have formalin fixed paraffin embedded tissue (from their primary or metastatic tumour) available for translational studies. * Presence of clinically and/or radiologically documented disease (measureable or non-measurable). All radiology studies must be performed within 28 days prior to registration (within 35 days if negative). * Androgen ablation must include either medical or surgical castration. If the patient is receiving medical androgen ablation, a castrate level of testosterone (\< 1.7 nmol/L) must be present. * Patients must have metastatic or locally recurrent disease, for which no curative therapy exists and for which systemic therapy is indicated. * No prior chemotherapy regimens for recurrent disease For Part A, patients must have progression defined as: PSA Progression: A rising PSA, while receiving androgen ablative therapy, with 2 subsequent rises over a reference value (not necessarily consecutively), measured a minimum of one week apart. The PSA that confirms progression must have a value of ≥ 5 ng/ml and must be performed no longer than 7 days prior to trial registration. OR Radiological Progression: defined as the development of new metastatic lesions with a stable or rising PSA. Patients entered to Part B of the study (after 2nd stage of accrual completed) must have a rise in their PSA while on abiraterone/prednisone continuing at time of registration (≥ 25% higher from baseline or nadir, whichever is lowest). * The PSA must be ≥5 ng/ml at the time of study entry. * ECOG performance of 0, 1 or 2. * Age ≥ 18 years of age. Previous therapy: Surgery: Previous major surgery is permitted provided that it has been at least 14 days prior to patient registration and that wound healing has occurred. Hormonal Therapy: Prior hormone therapy is required. Patients must be hormone refractory and have discontinued anti-androgens for at least 4 weeks prior to study entry (at least 6 weeks for bicalutamide). Therapy with LHRH agonist must continue for those prostate cancer patients already receiving this treatment at the time of enrollment. If the patient has discontinued the LHRH agonist, this must be restarted (if not surgically castrated) and the castrate level of testosterone must be present. Prior therapy with CYP17 inhibitors (e.g. abiraterone, ketoconazole) or novel anti-androgens (e.g. MDV3100) is permitted. Part B: Patients must be hormone refractory and have discontinued anti-androgens for at least 4 weeks prior to study entry (at least 6 weeks for bicalutamide). Therapy with LHRH agonist must continue for those prostate cancer patients already receiving this treatment at the time of enrollment. If the patient has discontinued the LHRH agonist, this must be restarted (if not surgically castrated) and the castrate level of testosterone must be present. All patients must currently be receiving abiraterone. Radiation: Prior external beam radiation is permitted provided a minimum of 2 weeks has elapsed between the last dose and enrollment to the trial. Exceptions may be made for low dose, non-myelosuppressive radiotherapy after consultation with NCIC CTG. Prior strontium is not permitted. \- Laboratory Requirements (must be done within 7 days prior to registration) Hematology: Granulocytes (AGC) ≥ 1.5 x 10\^9/L Platelets ≥ 100 x 10\^9/L Biochemistry: Serum creatinine ≤ 1.5 x UNL Total bilirubin ≤ 1.5 x UNL ALT and AST ≤ 1.5 x UNL Glucose ≤ 8.9 mmol/L (≤ Grade 1) PSA ≥ 5ng/mL -Patient consent must be appropriately obtained in accordance with applicable local and regulatory requirements. Each patient must sign a consent form prior to enrollment in the trial to document their willingness to participate. Patients who cannot give informed consent (i.e. mentally incompetent patients, or those physically incapacitated such as comatose patients) are not to be recruited into the study. Patients competent but physically unable to sign the consent form may have the document signed by their nearest relative or legal guardian. Each patient will be provided with a full explanation of the study before consent is requested. * Patients must be accessible for treatment and follow-up. Patients registered on this trial must be treated and followed at the participating centre. This implies there must be reasonable geographical limits (for example: 2 hour's driving distance) placed on patients being considered for this trial. Investigators must assure themselves that the patients registered on this trial will be available for complete documentation of the treatment, adverse events, response assessment and follow-up. * In accordance with NCIC CTG policy, protocol treatment is to begin within 5 working days of patient registration.

Exclusion criteria

* Patients with a history of other malignancies, except for adequately treated non-melanoma skin cancer or solid tumours curatively treated with no evidence of disease for \>=3 years. * Known HIV-positive patients. * Uncontrolled diabetes mellitus. * Patients with upper gastrointestinal or other conditions that would preclude compliance or absorption of oral medication are not eligible. * Patients with active or uncontrolled infections, or with serious illnesses or medical conditions which would not permit the patient to be managed according to the protocol. * Patients are not eligible if they have a known hypersensitivity to the study drug(s) or their components. * Patients with history of central nervous system metastases or untreated spinal cord compression. * Patients who have had prior treatment with a PI3 kinase inhibitor. * Men who are not sterile unless they use an adequate method of birth control. * Patients enrolled to Part B must be suitable for continued therapy with abiraterone/prednisone.

Design outcomes

Primary

MeasureTime frameDescription
Lack of Disease Progression at 12 Weeks12 weeksProportion of patients without evidence of progression (objective progression, defined as an increase in sum of diameters of target lesions of at least 20% above the lowest (or baseline) value (minimum of 5 mm increase) OR the appearance of unequivocal increase in non-measurable/non-target disease OR the appearance of new lesions, or PSA progression, defined as a rise in PSA of 25% (minimum 5 ng/ml) above baseline value or nadir, whichever is lowest, and confirmed by a second increasing value at least 3 weeks later) at 12 weeks after start of therapy

Secondary

MeasureTime frameDescription
PSA Response Rate12 weeksProportion of patients with PSA response defined as a \> 50% fall in PSA (minimum of 5 ng/ml) from baseline maintained for \> 4 weeks without evidence of disease progression otherwise
Objective Response Rate12 weeksProportion of patients with objective response defined as 30% decrease in the sum of the longest diameters of the target lesions (partial response) maintained for at least 4 weeks, or complete disappearance of disease and cancer related symptoms (complete response), also maintained for at least 4 weeks
Change in Circulating Tumour Cell Number During Treatment12 weeksProportion of patients with Favorable circulating tumour cell (CTC) conversion (\< 5 CTC/7.5 mL)

Countries

Canada

Participant flow

Participants by arm

ArmCount
Group A
Patients with castration resistant prostate cancer, who have received no prior chemotherapy regimens for recurrent disease, treated by PX-866 at 8mg when given orally daily
43
Group B
Patients with castration resistant prostate cancer, who have had PSA progression while receiving abiraterone/prednisonee, treated by PX-866 at 8mg when given orally daily
25
Total68

Baseline characteristics

CharacteristicGroup AGroup BTotal
Age, Continuous70 years72 years71 years
Ethnicity (NIH/OMB)
Hispanic or Latino
0 Participants0 Participants0 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
43 Participants25 Participants68 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants
Region of Enrollment
Canada
43 participants25 participants68 participants
Sex: Female, Male
Female
0 Participants0 Participants0 Participants
Sex: Female, Male
Male
43 Participants25 Participants68 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
6 / 435 / 25
other
Total, other adverse events
43 / 4325 / 25
serious
Total, serious adverse events
8 / 435 / 25

Outcome results

Primary

Lack of Disease Progression at 12 Weeks

Proportion of patients without evidence of progression (objective progression, defined as an increase in sum of diameters of target lesions of at least 20% above the lowest (or baseline) value (minimum of 5 mm increase) OR the appearance of unequivocal increase in non-measurable/non-target disease OR the appearance of new lesions, or PSA progression, defined as a rise in PSA of 25% (minimum 5 ng/ml) above baseline value or nadir, whichever is lowest, and confirmed by a second increasing value at least 3 weeks later) at 12 weeks after start of therapy

Time frame: 12 weeks

Population: All patients enrolled

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
Group ALack of Disease Progression at 12 Weeks14 Participants
Group BLack of Disease Progression at 12 Weeks11 Participants
Secondary

Change in Circulating Tumour Cell Number During Treatment

Proportion of patients with Favorable circulating tumour cell (CTC) conversion (\< 5 CTC/7.5 mL)

Time frame: 12 weeks

Population: All patients with CTC assessed (not required for Group B patients)

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
Group AChange in Circulating Tumour Cell Number During Treatment6 Participants
Group BChange in Circulating Tumour Cell Number During Treatment0 Participants
Secondary

Objective Response Rate

Proportion of patients with objective response defined as 30% decrease in the sum of the longest diameters of the target lesions (partial response) maintained for at least 4 weeks, or complete disappearance of disease and cancer related symptoms (complete response), also maintained for at least 4 weeks

Time frame: 12 weeks

Population: All patients enrolled

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
Group AObjective Response Rate2 Participants
Group BObjective Response Rate0 Participants
Secondary

PSA Response Rate

Proportion of patients with PSA response defined as a \> 50% fall in PSA (minimum of 5 ng/ml) from baseline maintained for \> 4 weeks without evidence of disease progression otherwise

Time frame: 12 weeks

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
Group APSA Response Rate1 Participants
Group BPSA Response Rate0 Participants

Source: ClinicalTrials.gov · Data processed: Mar 5, 2026