|Protalix reinforces case for taliglucerase alfa approval with new clinical data presentation|
|Thursday, 09 February 2012 06:29|
As readers may know, Taliglucerase alfa is the Company's proprietary plant cell expressed recombinant form of human Glucocerebrosidase (GCD), which is being developed for the treatment of Gaucher disease. Protalix' novel bioreactor plant cell system is based on disposable plastic vials that provides stable, optimized conditions, with manufacturing capabilities for the entire range of proteins, including antibodies, complex enzymes and plant-derived pharmaceuticals. Its patented bioreactor system utilizes sterilized, large flexible plastic containers for culturing and harvesting cells in consecutive cycles, with central unit providing oxygen and nutrients.
Last December, the firm received notification from the U.S. Food and Drug Administration (FDA) that the FDA had extended the Prescription Drug User Fee Act (PDUFA) goal date of the New Drug Application (NDA) for taliglucerase alfa by three-months from the previous PDUFA date of February 1, 2012.
In November 2011, the Company submitted certain clinical information regarding taliglucerase alfa in response to an FDA request. This request related mainly to the presentation of select data provided in the NDA and several analysts who follow the stock feel the chances for approval are good. The data presented by the company certainly appears to bolster that sentiment.Professor Ari Zimran, M.D., Director of the Gaucher Clinic, Shaare Zedek Medical Center, Jerusalem, Israel, is presenting long-term safety and efficacy data from the Company's double-blind, follow-on extension study of taliglucerase alfa for the treatment of Gaucher disease in naive patients. Eligible patients who completed nine months of treatment in the Company's pivotal phase III clinical trial were offered the opportunity to participate in the extension study and continue to receive taliglucerase alfa at the same dose they received in the phase III clinical trial for an additional 15 months in a blinded manner. Accordingly, the extension trial included two treatment groups; one treated with a 60 U/kg dose and the other with a 30 U/kg dose. The major endpoints of the study were spleen volume, liver volume, hemoglobin concentration, platelet count, and chitotriosidase activity. Twenty-six patients were enrolled in the extension trial which was performed in centers throughout Europe, Israel, North America, South America and South Africa.
Patients treated with taliglucerase alfa in the extension trial continued to demonstrate a statistically significant reduction in mean spleen volume after 24 months, compared with baseline, in both treatment groups. Both dosage groups demonstrated statistically significant mean reductions in spleen volume (details here).
The data also demonstrated statistically significant mean increases in platelet count for both groups. Last, statistically significant mean reductions in chitotriosidase activity were demonstrated by both groups.
"Pivotal and follow-up clinical studies of taliglucerase alfa to date demonstrate that taliglucerase alfa may be an effective treatment for Gaucher disease," said Dr. Ari Zimran. "The results of this 24 month extension trial suggest that taliglucerase alfa has the potential to become a treatment alternative for Gaucher disease patients should it be approved."
Gregory Pastores, M.D., Professor of Neurology and Pediatrics and Director of the Neurogenetics Laboratory at the New York University School of Medicine, is presenting at the WORLD 2012 Symposium the full results of all adult patients that participated in the Company's multi-center, open-label, nine month switchover trial of taliglucerase alfa for the treatment of Gaucher disease.
"The current findings are in accord with the interim observations made last year, which revealed maintenance of clinical benefit in patients switched from imiglucerase to taliglucerase across all doses. Additionally, all drug-related adverse effects were mild or moderate and transient in nature," said Dr. Gregory Pastores.
Last, Laura van Dussen, M.D., of the Academic Medical Center, University of Amsterdam, is presenting long term bone marrow responses, as measured by Quantitative Chemical Shift Imaging (QCSI) MRI, following treatment of Gaucher disease patients with taliglucerase alfa. Eight patients from the Company's pivotal and extension trial had their fat fraction evaluated by QCSI. At 24 months, seven of the eight patients demonstrated significant improvement in fat fraction from baseline. One patient remained unchanged. In addition, four patients whose score for bone was determined to be "at risk" at baseline (fat fraction <0.23) were no longer classified as "at risk" according to the protocol after 24 months of treatment with taliglucerase alfa.
Shares climbed over $1 since we reported that this data catalyst was coming in January. In addition, we told readers that Canaccord Genuity life sciences analyst Ritu Baral which assigned a "BUY," $8 target to the stock noted investor concern over the recent weakness in the Euro and, in a note to investors last month, highlighted biotech companies in her coverage universe with the greatest foreign currency exposure. Among them was Protalix. The Israel-based company reports in dollars. She notes an expected CHMP review date around mid-2012 for lead drug taliglucerase, a recombinant enzyme therapy for Gaucher’s disease. Canaccord also notes that the drug could receive approval in Israel and Brazil, both major Gaucher’s markets, shortly after US approval.