Data from a Phase 2 clinical study of IONIS-PKK-LRx from Ionis Pharmaceuticals, Inc. meets its primary and secondary endpoints, achieving significant reductions in the number of attacks suffered by patients with HAE compared to placebo. The study demonstrated a mean reduction of 90% in the number of monthly HAE attacks in weeks one to 17 of the study (p <0.001) and a mean reduction of 97% in the number of monthly HAE attacks in weeks five to 17 (p=0.003). In weeks five to 17, 92% of patients treated with IONIS-PKK-LRx were attack-free compared to 0% in the placebo group (p <0.001).

IONIS-PKK-LRx was developed using Ionis’ advanced ligand-conjugated antisense (LICA) technology. IONIS-PKK-LRx is one of Ionis’ wholly owned medicines to treat rare diseases.

IONIS-PKK-LRx is an investigational antisense medicine designed to reduce the production of prekallikrein, or PKK, which plays a key role in the activation of inflammatory mediators associated with acute attacks of HAE. Physicians have long prescribed prophylactic treatment approaches, including C1-INH replacement therapies and more recently inhibitors of plasma kallikrein, to prevent and reduce the severity of HAE attacks. Despite these available therapies, patients with HAE may experience breakthrough attacks.

“These topline Phase 2 study results support a profile for IONIS-PKK-LRx as a potential best-in-class prophylactic treatment for patients with HAE, with excellent efficacy, safety and tolerability along with the convenience of once per month low volume subcutaneous injections,” said Kenneth Newman, M.D., M.B.A., Ionis’ vice president of clinical development and leader of the pulmonology and immunology franchise. “These results highlight the potential benefits and advantages of IONIS-PKK-LRx for the treatment of hereditary angioedema and more broadly underscore the power of Ionis’ antisense technology to target the root causes of rare diseases like HAE.”

In the Phase 2 clinical study, 20 adults with Type 1 or Type 2 HAE were randomized and received either IONIS-PKK-LRx 80mg (n=14) or placebo (n=6) subcutaneously once monthly for 17 weeks. The primary endpoint was the reduction of monthly HAE attacks compared to placebo. Secondary endpoints included the reduction of monthly attacks  in weeks five to 17, reduction in the number of moderate or severe attacks in weeks one to 17, the number of moderate or severe attacks in weeks five to 17 and the number of attacks requiring acute therapy in weeks five to 17. The majority of adverse events during the study were mild with a frequency that was similar between groups. The most common treatment-emergent adverse events (TEAEs) were headache and nausea, which were seen more frequently in the placebo arm compared to the active treatment arm. Ionis expects to present a full analysis of its Phase 2 study of IONIS-PKK-LRx at a medical conference later this year.
(Source: Ionis)