Dyax Corp. Presents Phase 1b DX-2930 Data

Clinical data from Dyax Corp.’s DX-2930 Phase 1b study was selected as a late-breaking abstract and presented on June 7, 2015 at the European Academy of Allergy and Clinical Immunology (EAACI) Annual Congress in Barcelona, Spain. Discovered by Dyax, DX-2930 is an investigational fully human monoclonal antibody inhibitor of plasma kallikrein being developed for the prevention of HAE attacks.

The late-breaking, oral presentation, titled “Interim Analysis Results of a Phase 1b, Multiple Ascending Dose Study to Evaluate DX-2930, a Fully Human Monoclonal Antibody Inhibitor of Plasma Kallikrein in Development for Long-term Prophylaxis of Hereditary Angioedema,” was given by Aleena Banerji, M.D., Assistant Professor of Medicine at Harvard Medical School and attending physician at Massachusetts General Hospital. The oral presentation highlighted results from Dyax’s Phase 1b clinical study assessing the safety, tolerability and pharmacokinetics of DX-2930 in HAE patients.

“The clinical research findings presented at the EAACI Annual Congress continue to expand our understanding of the safety, pharmacokinetics and pharmacodynamics of DX-2930 in patients with HAE,” said Dr. Banerji. “Results from this study also provided proof-of-concept efficacy data demonstrating statistically significant reductions in attack rate compared to placebo. These results support further clinical investigation of DX-2930 in HAE patients to potentially prevent HAE attacks.”

“We are pleased to have our Phase 1b DX-2930 data selected for oral presentation at the EAACI,” said Burt Adelman, M.D., Executive Vice President of Research and Development and Chief Medical Officer at Dyax. “These data are significant because they indicate that DX-2930 may be a viable prophylactic treatment option for HAE. The 120-day follow-up period for the final dosing cohort was completed in May, and we look forward to reporting the full study results in the near future.”

The Phase 1b study results demonstrated that DX-2930 was well tolerated at all dose levels. There were no deaths or subject discontinuations due to an adverse event. There were no serious adverse events in subjects treated with DX-2930 and no evidence of dose-limiting toxicity. There was no safety signal in treatment-emergent adverse events, clinical laboratory results, vital signs, or electrocardiograms. Subcutaneous injection was well tolerated.

The Phase 1b study results demonstrated that DX-2930 was well tolerated at all dose levels. There were no deaths or subject discontinuations due to an adverse event. There were no serious adverse events in subjects treated with DX-2930 and no evidence of dose-limiting toxicity. There was no safety signal in treatment-emergent adverse events, clinical laboratory results, vital signs, or electrocardiograms. Subcutaneous injection was well tolerated.

Pharmacokinetic results demonstrated that DX-2930 has linear, dose-dependent exposure and a mean elimination half-life of approximately 14 days. Pharmacodynamic results from two different exploratory biomarker assays confirmed ex vivo plasma kallikrein inhibition in a dose- and time-dependent manner.

Primary proof-of-concept efficacy analyses were based on subjects in the 300 mg, 400 mg, and placebo dose groups who reported having at least 2 attacks in the 3 months prior to study entry. During the pre-specified, primary efficacy interval of 6 weeks (from days 8 to 50; corresponding to peak drug level), the HAE attack rate (adjusted for baseline attacks) was 0 in the 300 mg group and 0.045 attacks per week in the 400 mg group, compared to 0.37 attacks per week in the placebo group. This resulted in a 100% reduction for the 300 mg dose group as compared to placebo (P < 0.0001), and an 88% reduction for the 400 mg dose group as compared to placebo (P=0.005). During this primary efficacy interval, 100% of subjects in the 300 mg group (P=0.026) and 82% of subjects in the 400 mg group (P=0.030) were attack-free compared with 27% of subjects in the placebo group.

The Phase 1b study was a multi-center, randomized, double-blind, placebo-controlled, multiple-ascending dose study. A total of 37 subjects were randomized to active drug or placebo in a 2:1 ratio across 4 dosing groups of 30, 100, 300, or 400 mg. Each subject received two doses of DX-2930 or placebo, separated by 14 days, and was followed for 15 weeks after the second dose.

DX-2930 is a novel, fully human monoclonal antibody inhibitor of plasma kallikrein (pKal) which is currently being developed as a subcutaneous injection for the prevention of HAE attacks. Uncontrolled pKal activity leads to excessive generation of bradykinin, a vasodilator thought to be responsible for the localized swelling, inflammation and pain characteristically associated with HAE.

(Source: Dyax)