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

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.

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.