Aeglea Sells Experimental Argeinase 1 Deficiency Therapy to Immedica

Rare Daily Staff

Aeglea BioTherapeutics said it has entered into an agreement to sell the global rights to pegzilarginase, an experimental treatment for the rare metabolic disease Arginase 1 Deficiency to Immedica Pharma for $15 million in upfront cash proceeds and up to $100 million in contingent milestone payments.

The sale of pegzilarginase to Immedica supersedes the previous license agreement between Aeglea and Immedica.

The milestone payments are contingent on formal reimbursement decisions by national authorities in key European markets and pegzilarginase approval by the U.S. Food and Drug Administration, among other events. The upfront payment and contingent milestone payments if paid, net of expenses and adjustments, will be distributed to holders of Aeglea’s contingent value rights pursuant to the CVR agreement resulting from Aeglea’s acquisition of Spyre Therapeutics.

“Immedica has made substantial progress in working towards a European market approval,” said Jonathan Alspaugh, president and CFO of Aeglea. “We believe it is ultimately in the best interest of the ARG1-D community that Immedica will seek to continue the dialogue with the FDA to discuss a path forward for pegzilarginase in the United States while advancing the program globally.”

Arginase 1 Deficiency (ARG1-D) is an autosomal recessive condition resulting from a mutation that leads to a deficiency in the enzyme arginase, which leads to the inability to breakdown the amino acid arginine and remove ammonia from the blood. Symptoms usually begin around one to three years of age and include delayed growth, developmental delays, balancing trouble, tight muscles, irritability, poor appetite, vomiting, weak muscle tone, breathing trouble, trouble regulating body temperature, small head size, and hyperactivity. It is a rare debilitating disease that can lead to severe progressive neurological abnormalities and early mortality.

Pegzilarginase is a novel recombinant human enzyme engineered to degrade the amino acid arginine and has been shown to rapidly and sustainably lower levels of the amino acid arginine in plasma. Pegzilarginase has been in development for the treatment of people with ARG1-D.

The PEACE phase 3 clinical trial met its primary endpoint with a 76.7 percent reduction in mean plasma arginine compared to placebo. Additionally, 90.5 percent of pegzilarginase treated patients achieved normal plasma arginine levels.

Based on the results from PEACE and a previous phase 1/2 clinical trial, a Marketing Authorization application was submitted to the European Medicines Agency by Immedica. In April 2022, Aeglea announced the submission of a Biologics License Application to the U.S. Food and Drug Administration. The FDA, though, rejected the application in June 2022 and said it would not review it because it lacked clinical data demonstrating evidence of a treatment effect.

Photo: Jonathan Alspaugh, president and CFO of Aeglea