Zystor

Zystor Therapeutics Inc. operated as a privately held biotechnology firm, established in 2004 and headquartered in Milwaukee, Wisconsin. The company focused on developing enzyme replacement therapies (ERT) to treat a group of over 40 rare genetic disorders known as lysosomal storage diseases. These diseases stem from deficiencies in specific lysosomal enzymes.

The company's core asset was its proprietary Glycosylation Independent Lysosomal Targeting (GILT) technology. This platform was engineered to improve the delivery of therapeutic enzymes to essential tissues. Unlike conventional methods that rely on mannose-6-phosphate (M6P) to target enzymes to lysosomes, the GILT technology utilized a specific peptide tag. This peptide tag targets the M6P receptor with a significantly higher affinity, enhancing the uptake of the replacement enzyme into the target cells. The company's lead product candidate, ZC-701, was a novel fusion protein of insulin-like growth factor 2 and alpha-glucosidase (IGF2-GAA), developed for the treatment of Pompe disease. Preclinical studies indicated that ZC-701 could clear glycogen storage in muscle tissues more effectively than existing treatments.

Zystor's business model was centered on the research and development of these specialized therapeutics, with the goal of bringing them to clinical trials and eventual commercialization. On its journey, the company secured significant venture capital funding. A notable Series A funding round on December 15, 2004, raised $8.5 million from a syndicate of investors including Mason Wells, Venture Investors, Prolog Ventures, and the State of Wisconsin Investment Board, among others. The firm's trajectory culminated on August 17, 2010, when it was acquired by BioMarin Pharmaceutical Inc. The acquisition deal was valued at $22 million upfront, with potential for an additional $93 million based on the achievement of specific development, regulatory, and commercial milestones.

Keywords: enzyme replacement therapy, lysosomal storage diseases, biotechnology, GILT technology, Glycosylation Independent Lysosomal Targeting, Pompe disease, ZC-701, protein therapeutics, rare genetic disorders, BioMarin Pharmaceutical, preclinical development, venture capital, pharmaceutical acquisition, targeted therapies, alpha-glucosidase, IGF2-GAA, Milwaukee biotech, orphan diseases, drug development, therapeutic enzymes, M6P receptor, peptide tag technology, glycogen storage, protein engineering