Pilot Study to Evaluate Reparixin With Weekly Paclitaxel in Patients With HER 2 Negative Metastatic Breast Cancer (MBC)

This is a phase I study to evaluate the safety and define the pharmacokinetic (PK) profile of orally administered reparixin in combination with paclitaxel in HER 2 (Human epidermal growth factor receptor-2) negative metastatic breast cancer patients.

The primary objective of this study was to evaluate the safety and define the pharmacokinetic (PK) profile of orally administered reparixin in combination with paclitaxel in HER-2 negative MBC patients.

The secondary objectives were to:

1. Evaluate the effects of orally administered reparixin on cancer stem cell (CSC) markers, the tumoral microenvironment and markers of cytokine inflammation;
2. Evaluate peripheral blood samples for enumeration of circulating tumor cells (CTCs), molecular characterization as CSCs and perform epithelial-mesenchymal transition (EMT) biomarker profiling;
3. Assess disease response for indication of efficacy.

The CSC (Cancer stem cell) concept has important implications for understanding carcinogenesis as well as for the development of cancer therapeutics. According to this concept, tumors are initiated and maintained by a cellular subcomponent that displays stem cell properties. These properties include self-renewal, which drives tumorigenesis, and differentiation (albeit aberrant), which contributes to tumor cellular heterogeneity. The existence of CSCs has been described in a variety of hematologic and solid tumors including those of the breast, brain, colon, pancreas, lung, liver, and head and neck. In addition to driving tumorigenesis, CSCs may contribute to tumor metastasis as well as to tumor recurrence after treatment.

One of the therapeutic strategies being pursued to target CSCs involves inhibition of self renewal or survival pathways in these cells. These pathways include NOTCH (Notch signaling pathway), Hedgehog, and WNT (Wnt signaling pathway). Such strategies may be limited by the role of these pathways in normal stem cell function, which could result in systemic toxicities from pathway inhibition. In addition to intrinsic pathways regulating stem cell functions, normal and malignant stem cells are regulated by extrinsic signals generated in the microenvironment or CSC niche. In the breast, this niche is composed of immune cells, mesenchymal elements that include fibroblasts, endothelial cells, adipocytes, and extracellular matrix components. These components play an important role in normal breast development and carcinogenesis. If the cellular microenvironment plays an important role in the regulation of CSC growth and survival, then strategies aimed at interfering with these interactions represent a rational approach to target breast CSCs.

There are limited data on the impact of treatment tailoring based on CSCs detection. Gene profiling of CSCs could lead to identification of therapeutic targets on CSCs (e.g. hormone receptors, HER-2 \[Human epidermal growth factor receptor-2\] expression, EGFR \[Epidermal growth factor receptor\] expression), and could represent tumor biopsy in "real time". Several groups showed frequent discordance of HER-2 status between primary tumor and CSCs, and case reports showed clinical utility to use of trastuzumab-based therapy based on HER-2 CSCs status. Similarly, the hormonal status of CSCs could be different from that of the primary tumor, which could lead to increase the number of patients suitable for endocrine therapy, but also could explain why endocrine therapy fails in a subset of hormone receptor-positive patients. The study provided the in vivo demonstration that CXCR-1 (Chemokine receptor 1) targeting with specific blocking antibodies or reparixin is associated with reduced systemic metastases. The experimental data provides another therapeutic target in metastatic disease and warrants a pilot study investigation in humans to further explore effects of reparixin on breast CSCs and the tumoral microenvironment.

Reparixin seems to be a good candidate for use in breast cancer patients because of its very acceptable toxicity profile shown in the Phase I and II clinical trials conducted so far, along with its observed activity in vitro against breast cancer cell lines and in vivo in tumor xenografts in mice. It potentially addresses another therapeutic target in metastatic disease. The current pilot study thus aims at exploring the safety and PK profile of orally administered reparixin in HER-2 negative metastatic breast cancer patients and its effects on breast CSC markers.

Eligibility Criteria:
Inclusion Criteria:

1. Female aged ≥ 18 years.
2. Patients with histologic or cytologic diagnosis of breast cancer with evidence of metastatic disease with documented HER-2 negative status and eligible for treatment with paclitaxel.
3. Patients with at least one baseline measurable lesion according to RECIST version 1.1 criteria.
4. Zubrod (Eastern Co-operative Oncology Group \[ECOG\]) Performance Status (PS) of 0-1.
5. An electrocardiogram (ECG) with no clinically significant abnormalities indicative of myocardial ischemia.
6. Ongoing toxicity associated with prior anticancer therapy ≤ grade 1 Common Terminology Criteria for Adverse Events (CTCAE version 4.03) with the exception of alopecia.
7. Maximum of three prior chemotherapy lines for advanced breast cancer (not including neo/adjuvant chemotherapy). If prior treatment with paclitaxel, PD must have occurred \> 12 months from the end of previous adjuvant treatment or for previous metastatic treatment no PD must have occurred during treatment or within 3 months of the end of treatment
8. Life expectancy of at least three months.
9. Patients must be able to swallow and retain oral medication (intact tablet).
10. Able to undergo all screening assessments outlined in the protocol following written informed consent.
11. Adequate organ function (defined by the following parameters):

    1. Serum creatinine \< 140 µmol/L or creatinine clearance \> 60 mL/min.
    2. Serum hemoglobin ≥ 9 g/dL; absolute neutrophil count ≥ 1.5 x 10\*\*9/L; platelets ≥ 100 x 10\*\*9/L.
    3. Serum bilirubin ≤ 1.5 x upper normal limit (UNL).
    4. Serum ALT, AST ≤ 2.5 x UNL but ≤ 5.0 x UNL in case of liver metastases; ALP ≤ UNL but ≤ 1.5 x ULN in case of liver metastases; albumin within normal limits. If ALP is greater than 1.5 x UNL (in the presence of liver metastases) the liver isoenzyme fraction will be measured. Liver isoenzyme fraction (absolute value) must be ≤ 1.5 x UNL.
12. No known hepatitis B virus (not due to immunization), hepatitis C virus, human immunodeficiency virus Ι and -ΙΙ positive status.

Exclusion Criteria:

1. Male.
2. Pregnancy or lactation or unwillingness to use adequate method of birth control.
3. HER-2 positive disease status.
4. Less than four weeks since last chemotherapy, radiotherapy or prior investigational therapy. Less than two weeks since last hormone or immunotherapy or signal transduction therapy.
5. Neurological or psychiatric disorders which may influence understanding of study and informed consent procedures.
6. Active or uncontrolled infection.
7. Malabsorption syndrome, disease significantly affecting gastrointestinal function.
8. Hypersensitivity to:

   1. paclitaxel
   2. ibuprofen or to more than one non-steroidal anti-inflammatory drug.
   3. medications belonging to the class of sulfonamides, such as sulfamethazine, sulfamethoxazole, sulfasalazine, nimesulide or celecoxib.
9. Presence of brain metastases (this does not include primary brain tumors) or leptomeningeal disease.