None listed
Conditions
Brief summary
The purpose of this study is determine whether it is possible to use a drug called prazosin when men are undergoing radiotherapy for the treatment of prostate cancer. Who is it for? You may be eligible for this study if you are an adult man who has been diagnosed with non-metastatic prostate cancer. Study details All participants in this study will be asked to take prazosin two times day starting the week before and until the completion of their radiotherapy treatment for prostate cancer. There will be 6 dose levels that participants could be assigned to depending at what stage they enroll; the doses range between 0.5mg twice daily and 5mg twice daily. The dose will start at 0.5mg twice daily one week before radiotherapy starts and, if necessary, increase each week until the target dose is reached. Participants will be monitored throughout the treatment period to determine if they are willing to take the medication alongside their radiation, and followed for 9 months for any side effects. Participants will also be asked to provide blood samples at 3, 6 and 9 months after commencing the study, however these are part of standard follow-up tests after radiotherapy for prostate cancer. It is hoped that this study will help determine if it is possible to use prazosin while participants are completing radiotherapy, and help guide the development of a large scale clinical trial which will be used to investigate the efficacy of prazosin combined with radiotherapy
Interventions
This trial will be a feasibility study with dose escalation of the investigational drug (prazosin). The study will follow a standard 3 + 3 model followed by dose expansion. Each participant will remain on the same dose level throughout their treatment. Once dose escalation is complete all new participants will then be enrolled into the dose expansion phase. During the 3 + 3 phase, three participants will be enrolled to each dose level. If there are no dose limiting toxicities (DLT) at the respec
This trial will be a feasibility study with dose escalation of the investigational drug (prazosin). The study will follow a standard 3 + 3 model followed by dose expansion. Each participant will remain on the same dose level throughout their treatment. Once dose escalation is complete all new participants will then be enrolled into the dose expansion phase. During the 3 + 3 phase, three participants will be enrolled to each dose level. If there are no dose limiting toxicities (DLT) at the respective dose level the study will proceed to the next level. If one patient develops a DLT then an additional three patients will be enrolled into the dose level, should a second participant develop at DLT at the same level then the previous dose level will be defined as the maximum tolerated dose. It is planned that there will be 6 dose levels, 0.5mg, 1mg, 2mg, 3mg, 4mg and 5mg (all dosed twice daily), however if DLTs occur higher dose levels may not be reached. Participants will commence prazosin one week prior to the commencement of radiotherapy. Prazosin will be provided as 1mg, 2mg and 5mg tablets and dosing will commence one week prior to radiotherapy to enable dose titration and continue until the end of radiotherapy, approximately 4-6 weeks based on prescribed radiotherapy treatment plan. The appropriate tablet strength will be provided to the participant based on their dosing level. Participants will be enrolled into either the 0.5mg, 1mg, 2mg, 3mg, 4mg or 5mg dose levels, dosed twice daily. All patients will be commenced on 0.5mg (half of a 1mg tablet) of prazosin to be taken twice daily one week prior to the commencement of radiotherapy. For subsequent dose levels, the dose will be increased weekly. Compliance will be assessed at weekly review by the returning of all medication packaging and unused tablets. Participants will also be required to complete a dosing diary for the duration of treatment.
Sponsors
GenesisCare
Study design
Allocation
Non-randomised trial
Intervention model
Single group
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
Male
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
- Histologically confirmed adenocarcinoma of the prostate - Age greater or equal to 18 years - Normal liver function: ALT <2x ULN, Bilirubin <1.5 x ULN or normal conjugated bilirubin - Normal renal function: Serum urea and creatinine <1.5 ULN - ECOG performance status of 0-1 - Participants capable of childbearing only if using adequate contraception - Willingness to comply with all study procedures including IP administration protocol and required testing - Signed, written and informed consent - Participants are available for follow up
Exclusion criteria
- Evidence of >5 metastatic sites: Suspected or confirmed by appropriate imaging. - Under the age of 18 years - Presence of any medical, psychological or social condition that may hinder compliance - Use of hormonal therapy more than 30 days prior to commencement of prazosin, other than ADT prescribed for the treatment of PCa - History of any other previous malignancy within 5 years of the commencement of prazosin, other than successfully treated squamous cell or basal cell carcinoma of the skin - Has received prior brachytherapy or radiotherapy for PCa to the same site - Planned treatment with brachytherapy - Planned treatment with stereotactic ablative body radiotherapy (SABR) - Pre-existing hypotension defined as: Seated blood pressure < 100 mmHg systolic and/or < 70 mmHg diastolic - Pre-existing orthostatic hypotension defined as: Decrease in systolic blood pressure of 20 mm Hg or a decrease in diastolic blood pressure of 10 mm Hg within three minutes of standing when compared with seated blood pressure - Allergy to quinazolines - Treatment with a1-antagonists with the last 6 months: Including all drugs within the class e.g. tamsulosin, silodosin, doxazosin, alfuzosin and prazosin - Pre-existing cataract disease where cataract surgery is planned during the time that the patient would be receiving prazosin - Patients are high falls risk as assessed by physician - Planned cataract surgery - Concurrent participation in other clinical trials or use of other investigational products - Known gastrointestinal disease that could affect the absorption or tolerance of the IP
Outcome results
None listed