BioCryst Reports Results from Two Forodesine Oncology Studies
Top-line results from pivotal study in patients with relapsed or refractory cutaneous T-cell lymphoma
Interim results from a phase 2 study demonstrate clinical activity of forodesine in patients with chronic lymphocytic leukemia
BIRMINGHAM, Ala., Sep 15, 2010 (BUSINESS WIRE) -- BioCryst Pharmaceuticals, Inc. (NASDAQ: BCRX) today announced preliminary top-line results from its multinational, open-label, single-arm trial evaluating 200 mg once-daily oral forodesine in the treatment of relapsed or refractory cutaneous T-cell lymphoma (CTCL), as well as interim results from the Company's exploratory Phase 2 study to investigate the efficacy and safety of 200 mg twice-daily oral forodesine as monotherapy for chronic lymphocytic leukemia (CLL).
"These data expand our understanding of the potential role for forodesine and other purine nucleoside phosphorylase inhibitors in the treatment of patients with hematological malignancies," said Jon P. Stonehouse, President and Chief Executive Officer of BioCryst. "We believe PNP inhibition is a potentially interesting mechanism for combination with other therapies and for earlier lines of therapy, based on the clinical activity and tolerability of forodesine."
CTCL study top-line results
The study's primary endpoint was objective response rate, defined as complete or partial cutaneous response that is sustained for at least 28 days, in patients with later stage (stage IIB, III and IVA) disease who had previously received at least three systemic therapies for their disease. Eleven of 101 (11% [95% confidence interval: 6-19%]) later stage patients enrolled achieved a partial cutaneous response, while no patients achieved a complete response. Of the remaining later stage patients, 56 (55%) had stable disease as their best response, 30 (30%) had progressive disease, with a median time to progression of 353 days, and four (4%) were not evaluable. The median number of prior systemic therapies was four (range 3-15) among patients with later stage disease. Oral forodesine was generally safe and well-tolerated in this study, and was administered daily for up to 839 days.
"Heavily pretreated CTCL patients are in need of additional treatment options," said Dr. William P. Sheridan, Chief Medical Officer at BioCryst. "Two-thirds of the late-stage CTCL patients experienced stable disease or better, and forodesine was generally safe and well-tolerated at the dose evaluated in this study. The eleven percent response rate observed in this study population may reflect the impact of heavy pretreatment with multiple prior lines of therapy."
Eligible patients were those with CTCL of stages IB through IVA who have disease that was persistent, progressive or recurrent during or after treatment with at least three systemic therapies, one of which must have been oral bexarotene. A total of 144 patients with CTCL, with a median duration of illness of 52.5 months, were enrolled. The most common adverse events reported were peripheral edema, fatigue, insomnia, diarrhea, headache and nausea.
This trial was conducted under a Special Protocol Assessment (SPA) agreement negotiated with the U.S. Food and Drug Administration (FDA). Further details regarding the study design are available at the following clinicaltrials.gov link: http://clinicaltrials.gov/ct2/show/NCT00501735.
Exploratory Phase 2 CLL study interim results
This ongoing study enrolled 25 CLL patients who had failed at least one prior treatment regimen. The primary endpoint of this single-arm, open-label study was overall response rate. The interim analysis showed that three patients demonstrated a confirmed partial response to forodesine. Six patients remain enrolled in the study and on treatment. Five of the patients have been treated with forodesine twice-daily for longer than one year. Consistent with results of previous clinical trials, forodesine was generally safe and well-tolerated in this study. Final results from this study are expected later in 2010, and the Company plans to present the final results for presentation at an upcoming medical meeting.
"We are very encouraged with the response rate observed for forodesine administered as a single agent twice-daily in this refractory or relapsed CLL patient population," added Dr. Sheridan. "The efficacy, safety, tolerability and oral administration of the PNP inhibitor forodesine support its continued evaluation for this disease. In addition, these characteristics make forodesine attractive to combine with other active drugs for treatment of CLL."
Further details regarding the study design of the CLL study are available at the following clinicaltrials.gov link: http://clinicaltrials.gov/ct2/show/NCT00640523
About Cutaneous T-cell Lymphoma (CTCL)
CTCL affects approximately 18,000 people in the U.S. CTCL is a primary skin neoplasm and accounts for nearly 50% of all T-cell malignancies. Unlike most cancer patients, CTCL patients are treated chronically and could benefit from an oral agent that is well-tolerated like forodesine. Long term treatment (>12 months) of CTCL with forodesine in the supportive Phase 1/2 study suggests a favorable safety profile. This data was presented at ASCO in 2009.
About Chronic Lymphocytic Leukemia (CLL)
CLL is a blood and bone marrow disease that accounts for about one-third of all leukemias. It starts from white blood cells (called lymphocytes) in the bone marrow that then invade the blood system. CLL affects more than 8,000 people in the U.S. each year and according to the American Cancer Society, about 90,179 people were living with CLL in the U.S. in 2008. Most patients with CLL are older than 60. For more information on CLL, please visit the American Cancer Society at the following link: http://www.cancer.org/index.
BioCryst Pharmaceuticals designs, optimizes and develops novel small-molecule pharmaceuticals that block key enzymes involved in infectious diseases, cancer and inflammatory diseases. BioCryst has progressed two novel compounds that are in late-stage pivotal trials; peramivir, a neuraminidase inhibitor for the treatment of influenza, and forodesine, an orally-available purine nucleoside phosphorylase (PNP) inhibitor for cutaneous T-cell lymphoma (CTCL). Additionally, BioCryst has a third product candidate, BCX4208--a next generation PNP inhibitor--in mid-stage trials for the treatment of gout. Utilizing crystallography and structure-based drug design, BioCryst continues to discover additional compounds and to progress others through pre-clinical and early development to address the unmet medical needs of patients and physicians. For more information, please visit the Company's Web site at www.biocryst.com.