Trial Outcomes & Findings for Niraparib Before Surgery in Treating Patients With High Risk Localized Prostate Cancer and DNA Damage Response Defects (NCT NCT04030559)

Last Updated: 2026-05-14

Results Overview

Number of participants who achieve complete pathologic response defined as no tumor identified on hematoxylin and eosin (H\&E) stained sections in participants who receive neoadjuvant niraparib therapy prior to radical prostatectomy (RP).

Recruitment status

TERMINATED

Study phase

PHASE2

Target enrollment

11 participants

Primary outcome timeframe

Up to the time of radical prostatectomy procedure, about 5 months from start of treatment.

Results posted on

2026-05-14

Participant Flow

Participant milestones

Participant milestones
Measure	Treatment (Niraparib) Patients receive niraparib PO QD on days 1-28. Treatment repeats every 28 days for up to 3 cycles in the absence of disease progression or unacceptable toxicity. Following completion of treatment, patients then undergo standard of care surgery. Niraparib: Given PO Niraparib Tosylate Monohydrate: Given PO Radical Prostatectomy: Undergo standard of care surgery
Overall Study STARTED	11
Overall Study COMPLETED	11
Overall Study NOT COMPLETED	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Niraparib Before Surgery in Treating Patients With High Risk Localized Prostate Cancer and DNA Damage Response Defects

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Treatment (Niraparib) n=11 Participants Patients receive niraparib PO QD on days 1-28. Treatment repeats every 28 days for up to 3 cycles in the absence of disease progression or unacceptable toxicity. Following completion of treatment, patients then undergo standard of care surgery. Niraparib: Given PO Niraparib Tosylate Monohydrate: Given PO Radical Prostatectomy: Undergo standard of care surgery
Age, Categorical <=18 years	0 Participants n=1512 Participants
Age, Categorical Between 18 and 65 years	1 Participants n=1512 Participants
Age, Categorical >=65 years	10 Participants n=1512 Participants
Sex: Female, Male Female	0 Participants n=1512 Participants
Sex: Female, Male Male	11 Participants n=1512 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	0 Participants n=1512 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	10 Participants n=1512 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	1 Participants n=1512 Participants
Region of Enrollment United States	11 participants n=1512 Participants

PRIMARY outcome

Timeframe: Up to the time of radical prostatectomy procedure, about 5 months from start of treatment.

Population: Nine participants went on to radical prostatectomy (RP) while two patients chose to undergo radiotherapy. No complete or partial pathologic responses were observed in those who went on to RP.

Outcome measures

Outcome measures
Measure	Treatment (Niraparib) n=9 Participants Participants receive niraparib PO QD on days 1-28. Treatment repeats every 28 days for up to 3 cycles in the absence of disease progression or unacceptable toxicity. Following completion of treatment, patients then undergo standard of care surgery. Niraparib: Given PO Niraparib Tosylate Monohydrate: Given PO Radical Prostatectomy: Undergo standard of care surgery
Pathologic Response Rate (pRR)	0 Participants

SECONDARY outcome

Timeframe: Up to about 5 years from start of treatment.

Number of participants who achieve biochemical (PSA) progression free survival (bPFS).

Outcome measures

Outcome measures
Measure	Treatment (Niraparib) n=9 Participants Participants receive niraparib PO QD on days 1-28. Treatment repeats every 28 days for up to 3 cycles in the absence of disease progression or unacceptable toxicity. Following completion of treatment, patients then undergo standard of care surgery. Niraparib: Given PO Niraparib Tosylate Monohydrate: Given PO Radical Prostatectomy: Undergo standard of care surgery
Biochemical Prostate Specific Antigen (PSA) Progression Free Survival	56 percentage of evaluable participants

Adverse Events

Treatment (Niraparib)

Serious events: 1 serious events

Other events: 11 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	Treatment (Niraparib) n=11 participants at risk Patients receive niraparib PO QD on days 1-28. Treatment repeats every 28 days for up to 3 cycles in the absence of disease progression or unacceptable toxicity. Following completion of treatment, patients then undergo standard of care surgery. Niraparib: Given PO Niraparib Tosylate Monohydrate: Given PO Radical Prostatectomy: Undergo standard of care surgery
Investigations Platelet count decreased	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.

Other adverse events

Other adverse events
Measure	Treatment (Niraparib) n=11 participants at risk Patients receive niraparib PO QD on days 1-28. Treatment repeats every 28 days for up to 3 cycles in the absence of disease progression or unacceptable toxicity. Following completion of treatment, patients then undergo standard of care surgery. Niraparib: Given PO Niraparib Tosylate Monohydrate: Given PO Radical Prostatectomy: Undergo standard of care surgery
Gastrointestinal disorders Abdominal pain	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Investigations Alanine aminotransferase increased	18.2% 2/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Investigations Alkaline phosphatase increased	18.2% 2/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Blood and lymphatic system disorders Anemia	36.4% 4/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Metabolism and nutrition disorders Anorexia	18.2% 2/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Psychiatric disorders Anxiety	18.2% 2/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Investigations Aspartate aminotransferase increased	27.3% 3/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Musculoskeletal and connective tissue disorders Back pain	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Gastrointestinal disorders Bloating	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Investigations Blood bicarbonate decreased	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Investigations Blood bilirubin increased	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Investigations Blood lactate dehydrogenase increased	36.4% 4/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Eye disorders Blurred vision	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
General disorders Chills	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Gastrointestinal disorders Constipation	27.3% 3/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Respiratory, thoracic and mediastinal disorders Cough	27.3% 3/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Investigations Creatinine increased	36.4% 4/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Gastrointestinal disorders Diarrhea	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Nervous system disorders Dysgeusia	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Nervous system disorders Dysphasia	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Respiratory, thoracic and mediastinal disorders Dyspnea	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Respiratory, thoracic and mediastinal disorders Epistaxis	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
General disorders Fatigue	63.6% 7/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
General disorders Fever	18.2% 2/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Gastrointestinal disorders Flatulence	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Eye disorders Floaters	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Investigations GGT increased	18.2% 2/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Nervous system disorders Headache	27.3% 3/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Metabolism and nutrition disorders Hypercalcemia	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Metabolism and nutrition disorders Hyperglycemia	54.5% 6/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Metabolism and nutrition disorders Hyperkalemia	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Metabolism and nutrition disorders Hypocalcemia	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Metabolism and nutrition disorders Hypokalemia	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Metabolism and nutrition disorders Hypomagnesemia	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Metabolism and nutrition disorders Hyponatremia	18.2% 2/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Metabolism and nutrition disorders Hypophosphatemia	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Psychiatric disorders Insomnia	18.2% 2/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Investigations Lymphocyte count decreased	63.6% 7/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Musculoskeletal and connective tissue disorders Leg cramps	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Musculoskeletal and connective tissue disorders Myalgia	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Gastrointestinal disorders Nausea	36.4% 4/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Investigations Neutrophil count decreased	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Musculoskeletal and connective tissue disorders Pain	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Cardiac disorders Palpitations	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Renal and urinary disorders Proteinuria	9.1% 1/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Gastrointestinal disorders Vomiting	18.2% 2/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.
Investigations White blood cell decreased	27.3% 3/11 • Up to 5 months for adverse events and serious adverse events. Up to about 5 years or all-cause mortality.

Additional Information

Office of Clinical Research

University of California, Davis

Phone: 916-382-6970

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place