Efficacy and Safety Study of REM-001 Photodynamic Therapy for Treatment of Cutaneous Metastatic Breast Cancer (CMBC)

Inclusion Criteria

• •Adult participants 18 years of age or greater.
• •Participants able and willing to sign informed consent.
• •Histopathologically confirmed breast cancer metastasis to the skin.
• •Cutaneous metastasis not suitable for surgical resection.
• •Eastern Cooperative Oncology Group (ECOG) performance status 0 to 2.
• •Symptomatic lesions (including discomfort, pain, discharge, ulceration).
• •Cutaneous, subcutaneous soft tissue, or superficial lymphatic metastasis that is amenable to PDT:
• •* Lesion(s) \> 10 mm and \< 60 mm in longest dimension.
• •* Lesion(s) exhibit at least one of the following symptoms: ulcerated, bleeding, discharging, itchy, painful.
• •* Judged by investigator as eligible for PDT.
• •Participants are radiotherapy refractory (have received a radiation dose of 60 gray (Gy) or greater to the ipsilateral thorax) or are not otherwise amenable to radiotherapy.
• •Disease progression on at least 2 courses of systemic therapy:
• •* HR positive/HER2 negative participants: should be refractory to endocrine therapy (at least 2 different regimens including at least one CDK4/6 inhibitor). Maintenance endocrine therapy at the clinician's discretion is allowed.
• •* HER2 positive participants should have had disease progression on at least 2 different regimens of HER2 targeted therapies. Maintenance therapy on trastuzumab (HERCEPTIN®) is allowed.
• •If participants are on systemic therapy at enrollment, they must meet the following:
• •* Participants must have undergone a minimum of two cycles of systemic therapy prior to enrollment.
• •* The systemic therapy must be one from the Treatment of Physician's Choice (TPC) list, as follows: : eribulin mesylate (Halaven®); capecitabine (Xeloda®); Gemcitabine (Gemzar®); a taxane \[either docetaxel (Taxotere®), nab-paclitaxel (Abraxane®), or paclitaxel (Taxol®)\]; vinorelbine (Navelbine®); an antibody-drug conjugate \[either sacituzumab-govitecan (Trodelvy®), trastuzumab-deruxtecan (Enhertu®), or ado-trastuzumab emtansine (KADCYLA®)\]; pembrolizumab (Keytruda®); or carboplatin (Paraplatin®).
• •* Patients who are not on any chemotherapy will also be eligible.
• •At the time of enrolment, participants should have no known plans to change or modify their TPC regimen while receiving study treatment. Note: TPC regimen may be changed or modified after treatment with REM-001 therapy, but this should be done in consultation with the Sponsor Medical Monitor.
• •Adequate renal function, as evidenced by estimated glomerular filtration rate (eGFR) \> 45 mL/min/1.73 m2 using the CKD-EPI Creatinine Equation without race.
• •Adequate bone marrow function as evidenced by absolute neutrophil count (ANC) ≥ 1.5 × 10\^9/L, hemoglobin ≥ 8.5 g/dL and platelet count ≥ 100 × 10\^9/L; INR \< 1.5.
• •Adequate liver function as evidenced by bilirubin ≤ 2.0 times the upper limits of normal (ULN) and alkaline phosphatase, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) ≤ 3 × ULN (in the case of liver metastases ≤ 5 × ULN) \[Participants with known Gilbert's Syndrome who have serum bilirubin \< 1.5 x ULN (NCI CTCAE v5.0 Gr 2) may be enrolled\].
• •QTCF \< 470msec on baseline ECG
• •Woman of childbearing potential (WOCBP) must have a negative serum pregnancy test documented within 7 days prior to registration and must agree to practice adequate contraception
• •Male patients must be sterile or willing to use an approved method of contraception from the time of treatment with REM-001 until 90 days after study drug treatment.