Radiation Therapy With or Without Olaparib in Treating Patients With Inflammatory Breast Cancer

PRIMARY OBJECTIVES:

I. To compare the Invasive Disease-Free Survival (IDFS) of patients with inflammatory breast
cancer receiving concurrent administration of olaparib with standard doses of radiotherapy to
the chest wall and regional lymph nodes compared to standard doses of radiotherapy alone to
the chest wall and regional lymph nodes.

SECONDARY OBJECTIVES:

I. To compare the effect of concurrent administration of olaparib with radiotherapy versus
radiotherapy alone on improvement in locoregional control (measured by Locoregional
Recurrence-Free Interval), Distant Relapse-Free Survival, and Overall Survival in
inflammatory breast cancer patients.

ADDITIONAL OBJECTIVES:

I. To collect tissue and whole blood for processing and banking in anticipation of future
correlative studies in this patient population.

OUTLINE: Participants are randomized to 1 of 2 groups.

GROUP I: Participants receive olaparib orally (PO) twice daily (BID) the day before standard
radiation therapy (RT) commences (Day 0) and throughout the RT course until the last day of
RT administration. Olaparib is also continued on weekends (routine days without RT)
throughout the RT course. Participants undergo radiation therapy 5 days per week for 6 weeks
in the absence of disease progression or unaccepted toxicity.

GROUP II: Participants undergo standard radiation therapy 5 days per week for 6 weeks in the
absence of disease progression or unaccepted toxicity.

After completion of study treatment, participants are followed up within 5 weeks, then every
3 months until 3 years after registration, and then every 6 months for up to 8 years after
registration.

Inclusion Criteria:

- Patients must have inflammatory breast cancer without distant metastases. All
biomarker subtype groups (estrogen receptor [ER], progesterone receptor [PR], HER2)
are eligible. Inflammatory disease will be defined per American Joint Committee on
Cancer (AJCC) 8th edition with documentation by history/exam and pathology at the time
of diagnosis.

- All patients must have completed neoadjuvant chemotherapy prior to mastectomy. The
chemotherapy regimen is at the discretion of the treating physician but it is
recommended that it include at least 4 cycles of anthracycline and/or taxane-based
therapy (plus targeted therapy for patients with HER2+ disease). Response to
chemotherapy is not a criterion for eligibility (both complete responders and those
with residual disease are eligible). Please note that although pathologic complete
response (pCR) is not required or excluded, pCR status must be determined post-surgery
prior to randomization.

- All patients must have undergone modified radical mastectomy (with negative margins on
ink) with pathologic nodal evaluation (from level I and II axillary lymph node
dissection) at least 3 weeks and no more than 12 weeks prior to randomization, unless
they receive additional chemotherapy after mastectomy. Patients must not have gross
residual tumor or positive microscopic margins after mastectomy.

- Additional adjuvant chemotherapy after surgery is allowed at the discretion of the
treating physician, either completed prior to randomization or planned for after
completion of protocol treatment. If adjuvant chemotherapy is administered after
mastectomy, the patient must be randomized at least 3 weeks but no more than 12 weeks
after the last dose of adjuvant chemotherapy.

- Patients must not have a history of radiation therapy to the ipsilateral chest wall
and/or regional nodes. Prior radiation therapy to other body sites is allowed.

- Patients must not be planning to receive any other investigational agents during
radiation therapy. Prior therapy, including prior treatment with olaparib or other
PARP inhibitor, is allowed.

- Patients must not have a known hypersensitivity to olaparib or any of the excipients
of the product.

- Patients must not have unresolved or unstable grade 3 or greater toxicity from prior
administration of another investigational drug and/or prior anti-cancer treatment.

- Patients must not be planning to receive strong or moderate CYP3A inhibitors or
inducers while on olaparib treatment. Patients receiving strong or moderate CYP3A
inhibitors must agree to discontinue use at least 2 weeks prior to receiving olaparib.
Patients receiving strong or moderate CYP3A inducers must agree to discontinue use at
least 5 weeks prior to receiving olaparib.

- Patients must not be planning to receive live virus or live bacterial vaccines while
receiving olaparib and during the 30 day follow up period

- Patients must not be planning to receive any additional anti-cancer therapy
(chemotherapy, endocrine therapy, immunotherapy, biological therapy or other novel
agent) while receiving radiotherapy with or without study medication. If a patient is
receiving concurrent anti-HER2 targeted therapies, they must not take these
medications during the period of radiotherapy (with or without study drug) while
enrolled on the study.

- Patients must have Zubrod performance status 0-2.

- Absolute neutrophil count (ANC) >= 1000/mm^3 (within 28 days prior to registration)

- Platelet count >= 100,000/mm^3 (within 28 days prior to registration)

- Hemoglobin >= 9.0 g/dL (after transfusion if required and within 28 days prior to
registration)

- Patients must have adequate renal function as evidenced by calculated creatinine
clearance >= 51 mL/min by Cockcroft-Gault equation, within 28 days prior to
registration. Calculated creatinine clearance = [(140 - age) x wt (kg) x 0.85 (if
female)]/[72 x creatinine (mg/dl)].

- Total bilirubin =< 1.5 x upper limit of normal (ULN) (within 28 days prior to
registration)

- Patients with documented Gilbert's disease may have bilirubin up to 2.5 mg/dL

- Serum glutamic-oxaloacetic transaminase (SGOT) =< 2.5 x ULN (within 28 days prior to
registration)

- Serum glutamate pyruvate transaminase (SGPT) =< 2.5 x ULN (within 28 days prior to
registration)

- Alkaline phosphatase =< 2.5 x ULN (within 28 days prior to registration)

- Patients must not have a history of other prior malignancy except for the following:
adequately treated basal cell or squamous cell skin cancer, in situ cervical cancer,
adequately treated stage I or II cancer from which the patient is currently in
complete remission, or any other cancer from which the patient has been disease free
for five years

- Female patients must be postmenopausal or have a negative urine or serum pregnancy
test within 28 days prior to registration. Female patients of childbearing potential
and male patients with partners of childbearing potential, who are sexually active,
must agree to the use of two highly effective forms of contraception.

- Patients who are breastfeeding must agree to discontinue breastfeeding before
receiving olaparib due to potential risk for adverse events in nursing infants
secondary to treatment of the mother with olaparib.

- Patients must not have active uncontrolled infection, symptomatic congestive heart
failure, unstable angina pectoris or cardiac arrhythmia.

- Patients must be able to swallow and retain oral medications and have no known
gastrointestinal disorders likely to interfere with absorption of the study
medication.

- Patients must not have a history of a resting electrocardiography (ECG) indicating
uncontrolled, potentially reversible cardiac conditions (such as unstable ischemia,
uncontrolled symptomatic arrhythmia, congestive heart failure, Fridericia's formula
corrected QT interval [QTcF] prolongation > 500 ms, electrolyte disturbances) or
congenital long QCYP3T syndrome.

- Patients must not have myelodysplastic syndrome (MDS)/acute myeloid leukemia (AML) or
with features suggestive of MDS/AML.

- Patient must not have had major surgery within 2 weeks of starting study treatments
and patients must have recovered from any effects of any major surgery.

- Patients must not have a history of uncontrolled ventricular arrhythmia, recent
(within 3 months) myocardial infarction, uncontrolled major seizure disorder, unstable
spinal cord compression, superior vena cava syndrome, or extensive interstitial
bilateral lung disease on high resolution computed tomography (HRCT) scan.

- Patients must not have had previous allogenic bone marrow transplant or double
umbilical cord blood transplantation (dUCBT).

- Patients must not have had whole blood transfusions in the last 120 days prior to
randomization.