REM-001 Trial Begins for Cutaneous Metastatic Breast Cancer Treatment

The REM-001 trial (NCT05374915) of REM-001 therapy for the treatment of patients with cutaneous metastatic breast cancer (CMBC) has begun.¹

REM-001 is a second-generation photodynamic therapy (PDT) photosensitizer. REM-001 therapy consists of 3 parts: a laser light source, a light delivery device, and the drug REM-001.²

The agent has multiple advantages over earlier generation PDT compounds and has undergone late-stage clinical development in prior studies. Findings have shown the agent to produce a complete response in approximately 80% of evaluable tumor sites.

"We are encouraged by the extensive data from prior REM-001 therapy trials supporting its strong efficacy in CMBC patients, providing us with an opportunity to address a significant unmet medical need," said Robert E. Hoffman, president and chief executive officer of Kintara, in a press release.¹ "With an 80% complete response rate for evaluable lesions in CMBC patients observed in previous late-stage clinical trials and the support of the [National Institutes of Health], along with the FDA's fast track designation, we are confident in the potential of REM-001 to help CMBC patients."

The open-label trial will consist of 15 patients with CMBC who will be treated with REM-001. In the trial, REM-001 will be evaluated at the 0.8 mg dose. Investigators also plan to optimize the study design in advance of the initiation of a phase 3 trial.³

All patients enrolled will be treated with physician's choice of therapy for systemic disease and have stable disease for at least 12 weeks.2 On day 1 of the treatment regimen, patients will receive REM-001 at a dosage of 0.8 mg/kg intravenously, administered at a rate of 2 mL/kg/hr over approximately 25 minutes. On day 2, light therapy will be applied to the treatment area, delivering 100 J/cm² over 10 minutes per treatment field. This light treatment will be initiated within 24 hours (plus or minus 2 hours) following the REM-001 infusion. The total treatment area for target lesions will not exceed 200 cm².

Participants will undergo assessment at specific intervals, including at weeks 1, 4, 8, 12, 16, 20, and 24. Additionally, an extra 4-week follow-up will be conducted if further confirmation is necessary after the 24-week mark.

Assessments throughout the treatment period will encompass various parameters, including evaluating cutaneous lesion response and measuring the area of ulceration through photographic imaging. Additionally, assessments will focus on identifying the presence or absence of ulceration, bleeding, discharge, and eschar formation. Patients will also provide feedback on pain and itch using numeric rating scales, allowing for subjective assessment.

Quality-of-life assessments will offer insight into the broader impact of the treatment on participants' well-being. Safety will be closely monitored throughout the study. On the first day of treatment, participants will undergo an electrocardiogram assessment following the infusion. Furthermore, a blood sample will be collected postinfusion to determine the concentration of REM-001 in plasma, providing crucial pharmacokinetic data.

Patients aged 18 years and older with histopathologically confirmed breast cancer metastasis to the skin will be enrolled in the study. Patients must have cutaneous metastasis not suitable for surgical resection; an ECOG performance status 0 to 2, symptomatic lesions; cutaneous, subcutaneous soft tissue, or superficial lymphatic metastasis that is amenable to photodynamic therapy; and lesion(s) > 10 mm and < 60 mm in longest dimension. Patients must also be radiotherapy-refractory or are not otherwise amenable to radiotherapy, have disease progression on at least 2 courses of systemic therapy, and have received 1 treatment of physician's choice for at least 3 months at screening. Moreover, patients with stable or responding systemic disease can continue to receive the same therapy during treatment. All patients must have adequate renal,, bone marrow, and liver functions.

The primary end point being investigated is best overall objective response rate (bORR) of the target treatment fields at any time from treatment up to, and including, week 24. bORR consists of complete responses or partial responses.

"CMBC is a devastating disease with limited treatment options for patients," said Alina Markova, MD, section head, general dermatology and oncodermatology at Memorial Sloan Kettering Cancer Center and principal investigator of the REM-001 15-patient study, in a press release.¹ "I am looking forward to testing the therapeutic potential of REM-001 in this trial and bringing novel therapies to CMBC patients to improve their quality-of-life.”

REFERENCES

1. Kintara Therapeutics announces initiation of REM-001 clinical trial for the treatment of cutaneous metastatic breast cancer. News release. Kintara Therapeutics, Inc. February 12, 2024. Accessed February 12, 2024. http://tinyurl.com/ycxwjmrp

2. REM-001: A proprietary late stage photodynamic therapy (PDT) platform. Kintara Therapeutics. Accessed February 12, 2024. https://www.kintara.com/pipeline/rem-001

3. Efficacy and safety study of REM-001 photodynamic therapy for treatment of cutaneous metastatic breast cancer (CMBC). ClinicalTrials.gov. Updated November 21, 2023. Accessed February 12, 2024. https://www.clinicaltrials.gov/study/NCT05374915?term=REM-001&rank=1