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CompletedNCT04024254Updated Mar 4, 2026Results posted

A Study of Serum Folate Levels in Patients Treated With Olaparib

A Phase 4 interventional study of Folic Acid Tablet in Ovarian Cancer, Breast Cancer and Folic Acid Deficiency, sponsored by Rush University Medical Center. Completed at 1 site in United States. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-03-04.

Sponsored by Rush University Medical Center · Phase 4, Interventional, and Treatment

Phase
Phase 4
Study type
Interventional
Enrollment
10
Allocation
Randomized
Ages
18 Years and older
Sex
Female
01

Study summary

This is a study investigating folate deficiency (lack of folic acid in the blood) in patients who take the drug olaparib to treat their advanced ovarian or breast cancer.

Read the detailed description

This is a study investigating folate deficiency (lack of folic acid in the blood) in patients who take the drug olaparib to treat their advanced ovarian or breast cancer. The primary goal of this study is to determine the frequency and timing of folate deficiency, and to learn more about whether giving folic acid supplementation (vitamin) will help delay or avoid deficiency in these patients. Deficiency can cause doctors to reduce or stop treatment with olaparib. In this case, patients are not getting the best treatment for their cancer due to the unwanted side effect.

02

Conditions studied

  • Ovarian Cancer
  • Breast Cancer
  • Folic Acid Deficiency

Keywords

  • ovarian cancer
  • breast cancer
  • olaparib
  • folic acid deficiency
03

In context

Ovarian Neoplasms

2,695 studies on the registry are indexed under Ovarian Neoplasms; 727 are open to participants now.

This study's enrollment of 10 is below the median of 60 across 2,030 interventional studies indexed under Ovarian Neoplasms.

Browse Ovarian Neoplasms studies →

Lead sponsor

Rush University Medical Center is the lead sponsor of 394 studies on the registry; 61 are open to participants now.

Of its 30 completed or terminated interventional studies of FDA-regulated products, 25 (83%) have results posted.

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

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Who can participate

Ages eligible
18 Years and older
Sexes eligible
Female
Accepts healthy volunteers
No

Inclusion criteria

  • Willing and able to provide signed informed consent
  • Female, post-menopausal, ≥18 years of age inclusive, at the time of signing the consent form
  • Individuals who have ovarian cancer or breast cancer who are recommended to start olaparib
  • Patients must have normal organ and bone marrow function measured within 28 days prior to administration of study treatment as defined below:
  • Haemoglobin ≥ 9 g/dL with no blood transfusion in the past 28 days
  • Absolute neutrophil count (ANC) ≥ 1.5 x 109/L
  • Platelet count ≥ 100 x 109/L
  • Total bilirubin ≤ 1.5 x institutional upper limit of normal (ULN)
  • Aspartate aminotransferase (AST) (Serum Glutamic Oxaloacetic Transaminase (SGOT)) / Alanine aminotransferase (ALT) (Serum Glutamic Pyruvate Transaminase (SGPT)) ≤ 2.5 x institutional upper limit of normal unless liver metastases are present in which case they must be ≤ 5x ULN
  • Patients must have creatinine clearance estimated of ≥51 mL/min
  • Eastern Cooperative Oncology Group (ECOG) performance status 0-1).
  • Patients must have a life expectancy ≥ 16 weeks.
  • At least one lesion (measurable and/or non-measurable) that can be accurately assessed at baseline by CT and is suitable for repeated assessment.

Exclusion criteria

Exclusion Criteria:

  • Patients with folic acid deficiency, defined as folate \<7 ng/mL, or those taking folic acid supplementation within 30 days of olaparib initiation.
  • Other malignancy unless curatively treated with no evidence of disease for ≥5 years except: adequately treated non-melanoma skin cancer, curatively treated in situ cancer of the cervix, ductal carcinoma in situ (DCIS), Stage 1, grade 1 endometrial carcinoma. Patients with a history of localised triple negative breast cancer may be eligible, provided they completed their adjuvant chemotherapy more than three years prior to registration, and that the patient remains free of recurrent or metastatic disease
  • Resting ECG indicating uncontrolled, potentially reversible cardiac conditions, as judged by the investigator (e.g., unstable ischemia, uncontrolled symptomatic arrhythmia, congestive heart failure, QTcF prolongation >500 ms, electrolyte disturbances, etc.), or patients with congenital long QT syndrome.
  • Persistent toxicities (>Common Terminology Criteria for Adverse Event (CTCAE) grade 2) caused by previous cancer therapy, excluding alopecia.
  • Patients with myelodysplastic syndrome/acute myeloid leukaemia or with features suggestive of MDS/AML.
  • Patients with symptomatic uncontrolled brain metastases.
  • Patients considered a poor medical risk due to a serious, uncontrolled medical disorder, non-malignant systemic disease or active, uncontrolled infection.
  • Patients unable to swallow orally administered medication and patients with gastrointestinal disorders likely to interfere with absorption of the study medication.
  • Immunocompromised patients, e.g., patients who are known to be serologically positive for human immunodeficiency virus (HIV).
  • Patients with known active hepatitis (i.e. Hepatitis B or C).
  • Any previous treatment with PARP inhibitor, including Olaparib.
  • Patients receiving any systemic chemotherapy or radiotherapy (except for palliative reasons) within 3 weeks prior to study treatment
  • Concomitant use of known strong CYP3A inhibitors (e.g., itraconazole, telithromycin, clarithromycin, protease inhibitors boosted with ritonavir or cobicistat, indinavir, saquinavir, nelfinavir, boceprevir, telaprevir) or moderate CYP3A inhibitors (e.g., ciprofloxacin, erythromycin, diltiazem, fluconazole, verapamil). The required washout period prior to starting olaparib is 2 weeks.
  • Concomitant use of known strong (e.g., phenobarbital, enzalutamide, phenytoin, rifampicin, rifabutin, rifapentine, carbamazepine, nevirapine and St John's Wort) or moderate CYP3A inducers (e.g., bosentan, efavirenz, modafinil). The required washout period prior to starting olaparib is 5 weeks for enzalutamide or phenobarbital and 3 weeks for other agents.
  • Major surgery within 2 weeks of starting study treatment and patients must have recovered from any effects of any major surgery.
  • Previous allogenic bone marrow transplant or double umbilical cord blood transplantation (dUCBT).
  • Whole blood transfusions in the last 120 days prior to entry to the study (packed red blood cells and platelet transfusions are acceptable).
  • Participation in another clinical study with an investigational product administered in the last 1 month
  • Patients with a known hypersensitivity to olaparib or any of the excipients of the product.
  • Patients with a known hypersensitivity to folic acid or any of the excipients of the product.
  • Involvement in the planning and/or conduct of the study
  • Judgment by the investigator that the patient should not participate in the study if the patient is unlikely to comply with study procedures, restrictions and requirements
  • Previous enrollment in the present study
  • Breast feeding women
05

Study design

Phase
Phase 4
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
10 participants (actual)

Study arms

  • Experimental
    Folic Acid supplementation

    Folic Acid supplement 1 mg by mouth daily

    Drug: Folic Acid Tablet

  • No intervention
    No Folic Acid Supplementation

    No Folic Acid supplementation.

Interventions

  • DrugFolic Acid Tablet

    Folic Acid 1 mg by mouth daily

06

What researchers measure

Primary outcomes

  1. Number of Participants Who Have Developed Folate Deficiency (Serum Folate Level < 7 ng/ml) on Olaparib

    The number of patients with ovarian and breast cancers who were treated with olaparib and developed folate deficiency was counted.

    Time frame: Serum folate levels were measured in each enrolled subject: at baseline, then every 2 weeks X 3 months, then monthly X 9 months. Accrual occurred over a 2-year period.

  2. Timing of Folate Deficiency Development

    The number of weeks between the beginning of olaparib treatment and the development of folate deficiency

    Time frame: From the beginning of olaparib treatment until the development of folate deficiency

Secondary outcomes

  1. The Number of Participants Who Developed Decreased Hemoglobin by ≥ 1 g/dl Relative to Baseline

    To evaluate the effect of olaparib on hemoglobin level in both arms of the study as compared to baseline before the beginning of the olaparib treatment

    Time frame: Hemoglobin levels were measured in each enrolled subject: at baseline, then every 2 weeks X 3 months, then monthly X 9 months. Accrual occurred over a 2-year period.

  2. Serum Folate

    To evaluate the effect of folic acid supplementation on serum folate levels as compared to the no Folate supplementation arm. Serum folate was measured every 2 weeks for the first 3 months, and then monthly for 9 months during olaparib therapy.

    Time frame: Serum folate levels were measured in each enrolled subject: at baseline, then every 2 weeks X 3 months, then monthly X 9 months. Accrual occurred over a 2-year period.

  3. Number of Participants Requiring Blood Transfusions

    The number of patients requiring blood transfusions during olaparib treatment was counted.

    Time frame: Over 12 months while on olaparib therapy.

  4. Number of Participants Requiring Olaparib Dose Interruptions

    The number of subjects requiring interruptions in olaparib treatment for any reason was counted.

    Time frame: Over 12 months while on olaparib therapy.

  5. Number of Participants Requiring Olaparib Dose Reductions for Any Reason

    The number of participants requiring olaparib dose reductions for any reason was counted.

    Time frame: Over 12 months while on olaparib therapy.

  6. Number of Participants Requiring Olaparib Discontinuation

    The number of subjects who had their olaparib treatment discontinued was counted.

    Time frame: Over 12 months while on olaparib therapy

07

Results

Posted Nov 21, 2025
Limitations and caveats
1. Low accrual at a single center led to a small sample size. 2. Close serum folate monitoring with early intervention for folate deficiency could have prevented more severe anemia, blood transfusions, and olaparib dose reductions. 3. Subjects were not blinded to results and may have altered their behavior. They were encouraged to hold folate-containing multivitamins but were not required to. 4. Olaparib-induced nausea and poor oral intake could have contributed to folate deficiency.

Participant flow

The protocol started in August 2020 and completed in August 2022. Patients were recruited from the Gynecologic Oncology and Breast Oncology clinics at a major medical center.

Participant flow — Overall Study
MilestoneFolic AcidNo Supplementation
Started27
Completed27
Not completed00

Outcome measures

PrimaryNumber of Participants Who Have Developed Folate Deficiency (Serum Folate Level < 7 ng/ml) on Olaparib

The number of patients with ovarian and breast cancers who were treated with olaparib and developed folate deficiency was counted.

Time frame:
Serum folate levels were measured in each enrolled subject: at baseline, then every 2 weeks X 3 months, then monthly X 9 months. Accrual occurred over a 2-year period.
Reported as:
Count of participants · Participants
Number of Participants Who Have Developed Folate Deficiency (Serum Folate Level < 7 ng/ml) on Olaparib
ParticipantsFolic Acid Supplementation ArmNo Supplementation
Number of Participants Who Have Developed Folate Deficiency (Serum Folate Level < 7 ng/ml) on Olaparib26
PrimaryTiming of Folate Deficiency Development

The number of weeks between the beginning of olaparib treatment and the development of folate deficiency

Time frame:
From the beginning of olaparib treatment until the development of folate deficiency
Reported as:
Mean · weeks
Timing of Folate Deficiency Development
weeksFolic Acid SupplementationNo Supplementation
Timing of Folate Deficiency Development4 (2 to 6)3.4 (2 to 8)
SecondaryThe Number of Participants Who Developed Decreased Hemoglobin by ≥ 1 g/dl Relative to Baseline

To evaluate the effect of olaparib on hemoglobin level in both arms of the study as compared to baseline before the beginning of the olaparib treatment

Time frame:
Hemoglobin levels were measured in each enrolled subject: at baseline, then every 2 weeks X 3 months, then monthly X 9 months. Accrual occurred over a 2-year period.
Reported as:
Count of participants · Participants
The Number of Participants Who Developed Decreased Hemoglobin by ≥ 1 g/dl Relative to Baseline
ParticipantsFolic AcidNo Supplementation
The Number of Participants Who Developed Decreased Hemoglobin by ≥ 1 g/dl Relative to Baseline12
SecondarySerum Folate

To evaluate the effect of folic acid supplementation on serum folate levels as compared to the no Folate supplementation arm. Serum folate was measured every 2 weeks for the first 3 months, and then monthly for 9 months during olaparib therapy.

Time frame:
Serum folate levels were measured in each enrolled subject: at baseline, then every 2 weeks X 3 months, then monthly X 9 months. Accrual occurred over a 2-year period.
Reported as:
Mean · ng/ml
Serum Folate
ng/mlFolic Acid Supplementation ArmNo Supplementation
2 week5.5 (3.6 to 7.3)7.7 (2.5 to 16.2)
4 week6.5 (5.5 to 21.5)4.6 (2.0 to 9.2)
6 week8.4 (7.5 to 9.3)7.8 (5.4 to 13.8)
8 week3.6 (3.6 to 3.6)4.0 (1.7 to 6.7)
10 week15.9 (15.9 to 15.9)8.1 (1.6 to 11.2)
12 week24.1 (9.6 to 38.6)6.1 (4.2 to 7.6)
14 weeks24.0 (24.0 to 24.0)10.5 (6.6 to 13.7)
5 month18.5 (8.3 to 28.7)9.5 (3.7 to 18.4)
6 month11.2 (3.8 to 18.7)5.6 (2.8 to 8.9)
7 month10.5 (9.3 to 10.8)6.8 (5.0 to 8.8)
8 month13.6 (10.5 to 16.7)5.8 (5.5 to 6.1)
9 month9.1 (9.1 to 9.1)8.2 (8.2 to 8.2)
10 month11.6 (8.5 to 14.7)7.5 (7.5 to 7.5)
11 month5.9 (5.1 to 6.6)6.8 (4.3 to 9.3)
12 month12.4 (12.4 to 12.4)9.3 (4.5 to 14.1)
30 day follow up6.0 (5.2 to 6.5)9.3 (3.2 to 16.2)
SecondaryNumber of Participants Requiring Blood Transfusions

The number of patients requiring blood transfusions during olaparib treatment was counted.

Time frame:
Over 12 months while on olaparib therapy.
Reported as:
Count of participants · Participants
Number of Participants Requiring Blood Transfusions
ParticipantsFolic AcidNo Supplementation
Number of Participants Requiring Blood Transfusions00
SecondaryNumber of Participants Requiring Olaparib Dose Interruptions

The number of subjects requiring interruptions in olaparib treatment for any reason was counted.

Time frame:
Over 12 months while on olaparib therapy.
Reported as:
Count of participants · Participants
Number of Participants Requiring Olaparib Dose Interruptions
ParticipantsFolic AcidNo Supplementation
Number of Participants Requiring Olaparib Dose Interruptions10
SecondaryNumber of Participants Requiring Olaparib Dose Reductions for Any Reason

The number of participants requiring olaparib dose reductions for any reason was counted.

Time frame:
Over 12 months while on olaparib therapy.
Reported as:
Count of participants · Participants
Number of Participants Requiring Olaparib Dose Reductions for Any Reason
ParticipantsFolic AcidNo Supplementation
Number of Participants Requiring Olaparib Dose Reductions for Any Reason02
SecondaryNumber of Participants Requiring Olaparib Discontinuation

The number of subjects who had their olaparib treatment discontinued was counted.

Time frame:
Over 12 months while on olaparib therapy
Reported as:
Count of participants · Participants
Number of Participants Requiring Olaparib Discontinuation
ParticipantsFolic AcidNo Supplementation
Number of Participants Requiring Olaparib Discontinuation01

Adverse events

Collected over Adverse events of olaparib therapy were collected for active participants from a range of 3 - 12 months.. Non-serious events are listed at a 0% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
Folic Acid0/2 (0%)0/2 (0%)0/2 (0%)
No Supplementation2/7 (28.6%)0/7 (0%)2/7 (28.6%)
Most frequent other events
Most frequent other events
EventFolic AcidNo Supplementation
FATIGUEGeneral disorders0/21/7
NAUSEAGastrointestinal disorders0/21/7

Baseline characteristics

Age, Categorical
Age, Categorical(Participants)Folic Acid Supplementation GroupNo SupplementationTotal
<=18 years000
Between 18 and 65 years235
>=65 years044
Age, Continuous
Age, Continuous(years)Folic Acid Supplementation GroupNo SupplementationTotal
Median49 (44 to 53)66 (43 to 89)64 (43 to 89)
Sex: Female, Male
Sex: Female, Male(Participants)Folic Acid Supplementation GroupNo SupplementationTotal
Female279
Male000
Ethnicity (NIH/OMB)
Ethnicity (NIH/OMB)(Participants)Folic Acid Supplementation GroupNo SupplementationTotal
Hispanic or Latino000
Not Hispanic or Latino279
Unknown or Not Reported000
Race (NIH/OMB)
Race (NIH/OMB)(Participants)Folic Acid Supplementation GroupNo SupplementationTotal
American Indian or Alaska Native000
Asian101
Native Hawaiian or Other Pacific Islander000
Black or African American055
White123
More than one race000
Unknown or Not Reported000
Region of Enrollment
Region of Enrollment(participants)Folic Acid Supplementation GroupNo SupplementationTotal
United States279
Folate levels at baseline
Folate levels at baseline(ng/mL)Folic Acid Supplementation GroupNo SupplementationTotal
Mean10.5 (7.3 to 13.7)18.6 (9.6 to 35.0)14.6 (7.3 to 35.0)
08

Study locations

1 site
  • Rush University Medical Center
    Chicago, Illinois 60612, United States
09

References and documents

Study documents

  • Protocol and statistical analysis plan · Nov 1, 2021
  • Informed consent form · Oct 20, 2022

Documents are hosted by the registry — open the source record to download them.

10

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Mar 4, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
11

Registry details

Key details

Study ID
NCT04024254
Lead sponsor
Rush University Medical Center
Responsible party
Lydia Usha (Professor of Medicine, Rush University Medical Center) — Principal investigator
First posted
Jul 18, 2019
Start date
Jul 21, 2020
Primary completion
Dec 31, 2025
Completion
Dec 31, 2025
Results posted
Nov 21, 2025
Last update
Mar 4, 2026

Study contacts

Lydia Usha, MD
principal investigator · Rush University Medical Center

Oversight

Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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