Rintatolimod, Celecoxib and Interferon Alpha 2b With Pembrolizumab For the Treatment of Patients With Metastatic or Unresectable Triple Negative Breast Cancer

PRIMARY OBJECTIVE:

I. To evaluate the safety profile of modified CKM (celecoxib, rintatolimod and interferon alpha-2b) regimen (replacement of INTRON [registered trademark] A, using alternative source of interferon alpha-2b [IFNalpha2b]) combined with pembrolizumab therapy in metastatic triple negative breast cancer patients.

SECONDARY OBJECTIVES:

I. To evaluate the efficacy of the CKM in combination with pembrolizumab in patients with metastatic triple negative breast cancer (mTNBC) as compared to historic outcomes of pembrolizumab and other anti-PD1/PD-L1 therapies alone, as determined by secondary measures of efficacy including:

Ia. Progression-free survival (PFS); Ib. Overall survival (OS); Ic. Overall response rate (ORR) to the combination therapy using Immune Modulated Response Evaluation Criteria in Solid Tumors (iRECIST); Id. Disease control rate (DCR) using iRECIST.

EXPLORATORY OBJECTIVES:

I. Examine the immune analysis profile of CKM and pembrolizumab combination:

Ia. Examine the relationship of infiltrating CD4+ and CD8+ T cells and other immune and genetic markers, and their associated PD-1, CD45RA or CD45RO levels; Ib. Correlate PD-L1 expression within both neoplastic and nonneoplastic stromal elements of the tumor microenvironment to PFS, OS, ORR and adverse events (AEs); Ic. Correlate immune panel results with ORR, PFS, OS and AEs.

II. Comparison of response assessment criteria for a prospective analysis:

IIa. Response evaluation criteria in solid tumors (RECIST) 1.1 response assessment; IIb. iRECIST response assessment.

OUTLINE: This is a phase I dose escalation study of interferon alpha-2b followed by a phase II study. Patients are assigned to 1 of 2 cohorts.

COHORT I: Patients receive rintatolimod intravenously (IV), celecoxib orally (PO), interferon alpha-2b IV on days 0, 1, and 2 of week 1 and days 7, 8, and 9 of week 2 on study. Patients receive pembrolizumab IV on day 9 and then every 3 weeks after that for up to 4 doses on study. Patients also undergo computed tomography (CT) scan or magnetic resonance imaging (MRI) at screening and follow-up and undergo blood sample collection during screening and on study.

COHORT II: Patients receive rintatolimod IV, celecoxib PO, and interferon alpha-2b IV on days 0, 1, and 2 of week 1 and days 7, 8, and 9 of week 2 on study. Patients receive pembrolizumab IV on day 2 of week 1 and then every 3 weeks beginning in week 4 on study. Patients also undergo CT scan or MRI at screening and follow-up, undergo blood sample collection during screening and on study, and may undergo tumor biopsy at screening and follow-up.

Inclusion criteria

• Age >= 18 years of age
• Have pathologically confirmed diagnosis of PDL-1-negative or PDL1 positive unresectable or metastatic TNBC with no curative treatment options
• Have been informed of other treatment options
• Patient has lesion that can be biopsied and is willing to undergo the procedure as part of the protocol. Note: For cohort 1 and cohort 2: Patient with accessible tumor will be offered optional pre-treatment and post-treatment biopsies. Biopsies are mandatory for cohort 3
• Have an Eastern Cooperative Oncology Group (ECOG) performance status of =< 1
• Participants of child-bearing potential must agree to use adequate contraceptive methods (e.g., hormonal or barrier method of birth control; abstinence) prior to study entry. Should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately
• Ability to swallow and retain oral medication
• Have measurable disease per RECIST 1.1 criteria present
• Any line of therapy allowed, radiologically confirmed progression
• No cancer-directed therapy for at least 3 weeks prior to study treatment (bone-directed therapies are allowed)
• Platelets >= 100,000/uL
• Hemoglobin >= 9.0 g/dL
• Absolute neutrophil count (ANC) >= 1500/uL
• Total bilirubin =< institutional upper limit of normal (ULN)
• Aspartate aminotransferase (AST) (serum glutamic oxaloacetic transaminase [SGOT]) and alanine aminotransferase (ALT) (serum glutamic pyruvic transaminase [SGPT]) =< 2.5 X institutional ULN
• Creatinine < ULN or, creatinine clearance >= 50 mL/min per Cockcroft-Gault equation for patients with creatinine levels greater than ULN
• Participant must understand the investigational nature of this study and sign an Independent Ethics Committee/Institutional Review Board approved written informed consent form prior to receiving any study related procedure

Exclusion criteria

• Patients currently treated with systemic immunosuppressive agents, including steroids (greater than equivalent of 10 mg daily of prednisone), are ineligible until 3 weeks after removal from immunosuppressive treatment. (Inhaled steroids are allowed.)
• Patients with active autoimmune disease or history of transplantation
• Pregnant or nursing female participants
• Unwilling or unable to follow protocol requirements
• Patients with known serious mood disorders. (Major depression diagnosis is an exclusion. Other stable mood disorders on stable therapy for > 6 months or not requiring therapy may be allowed after consultation with the principal investigator.)
• Cardiac risk factors including:

• Patients experiencing cardiac event(s) (acute coronary syndrome, myocardial infarction, or ischemia) within 3 months of signing consent. While our published clinical studies involving short-term CKM did not indicate increased risk of cardiac events, the CKM can induce flu-like symptoms, providing justification for its avoidance in patients with recent cardiac events
• Patients with a New York Heart Association classification of III or IV
• Patients with a history of stroke
• History of upper gastrointestinal ulceration, upper gastrointestinal bleeding, or upper gastrointestinal perforation within the past 3 years
• Prior allergic reaction or hypersensitivity to nonsteroidal antiinflammatory drug (NSAIDs) or any drugs administered on protocol
• Any condition which in the investigator's opinion deems the participant an unsuitable candidate to receive study drug
• Any patients with a positive antinuclear antibodies test will be excluded from study
• Has a known history of human immunodeficiency virus (HIV) infection
• Concurrent active hepatitis B (defined as hepatitis B antigen [HBsAg] positive and/or detectable hepatitis B virus [HBV] deoxyribonucleic acid [DNA]) and hepatitis C virus (defined as anti-hepatitis C virus [HCV] antibody [Ab] positive and detectable HCV ribonucleic acid [RNA]) infection. Note: Hepatitis B and C screening tests are not required unless known history of HBV and HCV infection