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Phase II, Dose Finding Study of GTx-758

Phase II, Open-label, Loading and Maintenance Dose Finding Study of GTx-758 in Men With Prostate Cancer

Status
Terminated
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01393119
Enrollment
77
Registered
2011-07-13
Start date
2011-08-31
Completion date
2012-12-31
Last updated
2024-04-22

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 determine the appropriate loading and maintenance dose of GTx-758 to reach and maintain castration for the duration of the study.

Detailed description

The original purpose of the study was to determine the appropriate loading and maintenance dose of GTx-758 to reach and maintain castration for the duration of the study. The primary endpoint was used to assess the loading dose, while the secondary endpoint was intended to be used to assess maintenance. Due to the study being terminated early, as requested by FDA, the secondary assessment of maintenance was unable to be assessed. Hence, all summaries provided are for subjects in the two loading dose groups of 1000 mg BID and 1500mg BID only and not broken out by the maintenance dose.

Interventions

3-fluoro-N-( 4-fluorophenyl)-4-hydroxy-N-( 4-hydroxyphenyl) benzamide; a nonsteroidal selective estrogen receptor (ER) a agonist

Sponsors

GTx
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
MALE
Age
45 Years to 80 Years
Healthy volunteers
No

Inclusion criteria

1. Be between age 45 and 80 years of age 2. Be able to communicate effectively with the study personnel 3. ECOG is ≤2 4. Screening serum total testosterone ≥150 ng/dL 5. Have prostate cancer, confirmed by pathology report 6. Have not been treated with ADT (chemical or surgical). If a subject has been treated with LHRHa for ≤6 months duration and that treatment was ≥1 years prior to the screening, the subject may be considered for the study. 7. Have a clinical indication for the initiation ADT. 8. Give written informed consent prior to any study specific procedures 9. Subjects must agree to use acceptable methods of contraception: * If their female partners are pregnant or lactating acceptable methods of contraception from the time of the first administration of study medication until 3 months following administration of the last dose of study medication must be used. Acceptable methods are: Condom used with spermicidal foam/gel/film/cream/suppository. If the subject has undergone surgical sterilization (vasectomy with documentation of azospermia) a condom with spermicidal foam/gel/film/cream/suppository should be used. * If the male subject's partner could become pregnant, use acceptable methods of contraception from the time of the first administration of study medication until 3 months following administration of the last dose of study medication. Acceptable methods of contraception are as follows: Condom with spermicidal foam/gel/film/cream/suppository \[i.e. double barrier method of contraception\], surgical sterilization (vasectomy with documentation of azospermia) and a double barrier method (condom used with spermicidal foam/gel/film/cream/suppository), the female partner uses oral contraceptives (combination estrogen/progesterone pills), injectable progesterone or subdermal implants and a double barrier method (condom used with spermicidal foam/gel/film/cream/suppository). * If the female partner has undergone documented tubal ligation (female sterilization), a double barrier method (condom used with spermicidal foam/gel/film/cream/suppository) should also be used. * If the female partner has undergone documented placement of an intrauterine device (IUD) or intrauterine system (IUS), a double barrier method (condom with spermicidal foam/gel/film/cream/suppository) should also be used.

Exclusion criteria

1. Known hypersensitivity or allergy to estrogen or estrogen like drugs 2. Have, in the judgment of the Investigator, a clinically significant concurrent illness or psychological, familial, sociological, geographical or other concomitant condition that would not permit adequate follow-up and compliance with the study protocol 3. History of abnormal blood clotting, Factor V Leiden clotting disorder, thrombotic disease (venous or arterial thrombotic events such as history of myocardial infarct (MI), stroke, deep vein thrombosis (DVT), and/or pulmonary embolus (PE)) NOTE: if there is evidence of an MI on the ECG that is not documented in the medical history or there is a history of MI greater than three years ago that has completely resolved, the eligibility of this subject per this exclusion criterion is an investigator decision and may require a consultation with a cardiologist. 4. Have ALT or AST above 2 times the upper limit of normal (ULN) 5. Have alkaline phosphatase greater than 3 times ULN and/or total bilirubin levels above 2 mg/dL at baseline 6. Patients cannot have brain or spinal cord metastases 7. Patients cannot have or be at high risk for spinal cord compression from bone metastases. 8. Received an investigational drug within a period of 90 days prior to enrollment in the study 9. Received the study medication previously 10. Currently taking testosterone, testosterone-like agents or antiandrogens, including 5-alpha reductase inhibitors (the subject may be considered for randomization after a 4 week washout period prior to randomization) 11. Currently taking Saw Palmetto or PC-SPES (the subject may be considered for randomization after a 4 week washout period prior to randomization) 12. Have taken diethylstilbestrol or other estrogen products within the previous 12 months prior to randomization into this study 13. Have taken body building or fertility supplements within 4 weeks of admission into the study (steroids and steroid like supplements) 14. Have a history of cancer other than prostate cancer, superficial bladder cancer (with no recurrence in the last 5 years) and/or non-melanoma carcinoma of the skin. 15. QTcB \>480 msec, If the first QTcB reading exceeds 480 msec two additional ECGs are to be performed separated at least 5 min apart, then take the average of the three QTcB readings to determine if the subject satisfies the above criteria. If the average QTcB reading is \> 480 msec then the subject is excluded.

Design outcomes

Primary

MeasureTime frameDescription
Percentage of Subjects That Reach Castration by Day 28Day 1-28Percentage of Patients Note: Due to the study being terminated early, per FDA, the secondary assessment of maintenance was unable to be assessed. Hence, all summaries provided are for subjects in the two loading dose groups of 1000 mg BID and 1500mg BID only. PLEASE NOTE: Study was terminated early, per FDA, the secondary assessment of maintenance was unable to be assessed. Hence, the efficacy summary provided are for subjects in the two loading dose groups of 1000 mg BID and 1500mg BID only, poling across maintenance doses within each loading dose. Safety/ITT - 27 and 28 patients, respectively mITT - 18 and 19 patients, respectively Note: mITT includes patients that meet the requirements for the efficacy analyses This format was agreed to by the PRS review team, per email communication on guidnace for presenting the data.

Countries

United States

Participant flow

Recruitment details

77 patients were screened with 19 discontinuing the study due to screen failure. 77-19=58 randomized subjects. Please note, 3 of these 58 subjects were randomized but not treated, as noted below, hence n=55 subjects are provided data for results summaries. Note: Due to study being terminated early, per FDA, secondary assessment of maintenance was not assessed. Hence, all summaries are for the two loading dose groups of 1000 mg BID and 1500mg BID only.

Pre-assignment details

Screen Failure subjects were not included in the outputs from the previous company who owned the product.

Participants by arm

ArmCount
Loading Dose 1000mg GTx-758 BID and Maintenance Dose of 1000mg GTx-758
Loading Dose 1000mg GTx-758 BID and Maintenance Dose of 1000mg GTx-758
13
Loading Dose 1000mg GTx-758 BID and Maintenance Dose of 2000mg GTx-758
Loading Dose 1000mg GTx-758 BID and Maintenance Dose of 2000mg GTx-758
14
Loading Dose 1500mg GTx-758 BID and Maintenance Dose of 1000mg GTx-758
Loading Dose 1500mg GTx-758 BID and Maintenance Dose of 1000mg GTx-758
13
Loading Dose 1500mg GTx-758 BID and Maintenance Dose of 2000mg GTx-758
Loading Dose 1500mg GTx-758 BID and Maintenance Dose of 2000mg GTx-758
15
Total55

Withdrawals & dropouts

PeriodReasonFG000FG001FG002FG003
Overall StudyAdverse Event1101
Overall StudyDeath0001
Overall StudyLack of Efficacy1021
Overall StudyProtocol Violation0010
Overall StudyRandomized but Not treated1011
Overall StudySponsor Termination of Study1112912
Overall StudyWithdrawal by Subject0110

Baseline characteristics

CharacteristicTotalLoading Dose 1000mg GTx-758 BID and Maintenance Dose of 1000mg GTx-758Loading Dose 1000mg GTx-758 BID and Maintenance Dose of 2000mg GTx-758Loading Dose 1500mg GTx-758 BID and Maintenance Dose of 1000mg GTx-758Loading Dose 1500mg GTx-758 BID and Maintenance Dose of 2000mg GTx-758
Age, Continuous
Age, Continuous
67.25 years
STANDARD_DEVIATION 6.9
64.8 years
STANDARD_DEVIATION 4.9
67.1 years
STANDARD_DEVIATION 8.4
68.0 years
STANDARD_DEVIATION 5.4
68.9 years
STANDARD_DEVIATION 8.2
Ethnicity (NIH/OMB)
Hispanic or Latino
2 Participants0 Participants0 Participants0 Participants2 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
53 Participants13 Participants14 Participants13 Participants13 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
Asian
2 Participants0 Participants1 Participants1 Participants0 Participants
Race (NIH/OMB)
Black or African American
13 Participants2 Participants3 Participants3 Participants5 Participants
Race (NIH/OMB)
More than one race
0 Participants0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
White
40 Participants11 Participants10 Participants9 Participants10 Participants
Sex/Gender, Customized
Males
55 Participants13 Participants14 Participants13 Participants15 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
EG002
affected / at risk
EG003
affected / at risk
deaths
Total, all-cause mortality
0 / 130 / 140 / 131 / 15
other
Total, other adverse events
10 / 1312 / 1410 / 1310 / 15
serious
Total, serious adverse events
2 / 131 / 140 / 133 / 15

Outcome results

Primary

Percentage of Subjects That Reach Castration by Day 28

Percentage of Patients Note: Due to the study being terminated early, per FDA, the secondary assessment of maintenance was unable to be assessed. Hence, all summaries provided are for subjects in the two loading dose groups of 1000 mg BID and 1500mg BID only. PLEASE NOTE: Study was terminated early, per FDA, the secondary assessment of maintenance was unable to be assessed. Hence, the efficacy summary provided are for subjects in the two loading dose groups of 1000 mg BID and 1500mg BID only, poling across maintenance doses within each loading dose. Safety/ITT - 27 and 28 patients, respectively mITT - 18 and 19 patients, respectively Note: mITT includes patients that meet the requirements for the efficacy analyses This format was agreed to by the PRS review team, per email communication on guidnace for presenting the data.

Time frame: Day 1-28

Population: Modified Intent to Treat Population

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
1000mg GTx-758 BIDPercentage of Subjects That Reach Castration by Day 2815 Participants
1500 mg GTx-758 BIDPercentage of Subjects That Reach Castration by Day 2816 Participants

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026