Rexahn Pharmaceuticals, Inc., a clinical stage biopharmaceutical company, announced the initiation of a Phase IIa clinical proof-of- concept trial to study the safety and efficacy of Archexin in patients with metastatic renal cell carcinoma (RCC).
In a release, the Company noted:
Archexin was previously granted Orphan Drug Designation for the RCC indication.
The Phase IIa Archexin proof-of-concept clinical trial is a multi- center study designed to evaluate the efficacy of Archexin in combination with everolimus (Afinitor) to treat metastatic RCC patients and will be conducted in two stages. Stage 1 will be dose ranging with up to 3 cohorts of 3 RCC patients to determine its maximum tolerated dose in combination with everolimus. Based on previous clinical data the target dose of Archexin is anticipated to be no more than 250 mg/m2 per day. The decision to enroll the next group of patients and escalate the dose will be made after completion of the first 21 day cycle of treatment. Patient assessments will include safety, pharmacokinetics, laboratory and physical exams. Once the maximum tolerated dose of Archexin in combination with everolimus has been determined, thirty RCC patients will be randomized to either Archexin in combination with everolimus or everolimus alone, in a ratio of 2:1.
The primary endpoint will be the percentage of progression free patients following eight cycles of therapy. Patients will be scanned (CT or MRI) for the assessment of tumor progression after every 2 cycles of therapy. Secondary endpoints include pharmacokinetic profile, incidence of adverse events, changes in clinical laboratory tests and vital signs over time, tumor response, duration of response, time to response, and response rate. Exploratory endpoints will include blood levels of AKT pathway biomarkers, tumor apoptosis biomarkers or other relevant biomarkers.
Peter D. Suzdak, Ph.D., Rexahn's Chief Executive Officer said, "The start of the Phase IIa clinical-proof-of-concept trial in RCC patients represents an important milestone for the Archexin clinical development program. The combination of strong scientific data, unmet clinical need, and our Orphan Drug Designation were all driving factors for choosing this indication."
Archexin is a specific inhibitor of the cancer cell signaling protein Akt-1. The activated form of Akt-1 (phospho-Akt-1) has been shown to be involved in cancer cell growth, survival, angiogenesis, and drug resistance. Phospho-Akt-1 has been shown to be significantly increased in more than 12 different human cancer cell lines including human renal cell carcinoma cells. Archexin has shown to inhibit the growth of human RCC cells in tissue culture and produce a substantial survival benefit in animal xenograft models of RCC. Archexin also exhibits additive anti-tumor effect when combined with other cancer drugs in inhibiting the growth of human RRC cells in tissue culture. In addition, resistance to the anti-cancer effects of clinically used mTOR inhibitors such as everolimus (Afinitor), which is used as second line therapy in RCC patients, has been attributed to an increase in Akt-1 activity. Thus, treatment with Archexin may both inhibit the growth/proliferation of RCC and overcome the resistance to mTOR inhibitors such as everolimus, resulting in an increase in efficacy.
Dr. Neeraj Agarwal MD, Director, GU Medical Oncology, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah, "The treatment of patients with metastatic RCC remains a significant unmet medical need. Selective Akt-1 inhibition represents a very promising new mechanism for the treatment of metastatic RCC. The potential to both inhibit the growth of RCC cells and affect the underlying mechanism responsible for the development of tolerance to second line therapies such as everolimus is very promising."
Following a scientific, clinical and business analysis of potential cancer indications for a new Phase IIa clinical trial with Archexin, Rexahn decided to pursue metastatic RCC. Metastatic RCC represents an attractive market opportunity with an estimated annual incidence of 90,000 patients world-wide and projected market size of greater than $6 billion. Metastatic RCC patients receiving standard of care treatment have a poor prognosis with an overall survival of less than 2 years. Rexahn has received the U.S. Food and Drug Administration's (FDA) Orphan Drug Designation for Archexin for metastatic RCC as well as four other cancers including pancreatic cancer.
Archexin is an anti-sense drug candidate that specifically inhibits the cancer cell signaling protein Akt-1. Archexin is the only specific inhibitor of Akt-1 in clinical development. The activated form of Akt-1, which is involved in cancer cell growth, survival, angiogenesis, and drug resistance, has shown to be present or elevated in more than 12 different human cancer cell lines, including pancreatic and renal cell carcinoma. By inhibiting Akt-1, Archexin has shown to both inhibit the growth of human renal cell carcinoma cell lines and exhibit a longer survival benefit in the human renal cell carcinoma animal xenograft model. Thus, while Akt- 1 is a very specific anti-cancer target it may have broad therapeutic potential across multiple types of cancer. Archexin has completed a Phase I clinical trial in cancer patients with solid tumors and was shown to be safe and well tolerated. The dose- limiting toxicity was a grade 3 fatigue. In a small Phase IIa trial in advanced pancreatic cancer patients, Archexin in combination with gemcitabine was shown to be safe and well tolerated. It demonstrated a preliminary efficacy signal with a median survival of 9.1 months in evaluable patients.
Rexahn Pharmaceuticals is a clinical stage biopharmaceutical company dedicated to developing therapeutics for the treatment of cancer.
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