The Dutch company Amsterdam Molecular Therapeutics Holding BV completed a €50 million (US$67 million) initial public offering to fund development of its gene-based therapies for orphan diseases.

Amsterdam-based AMT sold 5 million shares at €10 per share. ABN AMRO Rothschild and Kempen & Co. are underwriting the offering, and have an overallotment option to purchase up to 750,000 additional shares.

The shares, under the symbol "AMT," closed at €10.03 on the Euronext Exchange in Amsterdam in their debut Wednesday. The offering priced at the high range estimated when AMT filed its prospectus June 6. It said then it expected to sell up to 5 million shares at €8 to €10 per share.

The products in AMT's pipeline are based on its adeno-associated virus-based gene insertion technology platform and its baculovirus-based manufacturing platform. The technology is designed to insert the correct gene, potentially offering a long-term cure of the respective disease through one dose, rather than the continual treatment of symptoms or resulting disease complications.

It has six products in development, the lead being AMT-011 to treat the deficiency of the lipoprotein lipase (LPL) gene, or Type I hyperlipoproteinemia, a rare metabolic disease. AMT expects to file for approval in Europe in the first quarter of 2008, followed by filings in the U.S. and Canada. Some of the IPO funds are earmarked for building a specialized marketing and sales team to sell AMT-011 in Europe and North America.

The company also is in clinical development with AMT-011 for the treatment of Type V hyperlipoproteinemia. It has preclinical products in development for treating acute intermittent porphyria, hyperoxaluria, ApoA-1 deficiency and hemophilia B.

The company had about 13.9 million shares outstanding following the offering, giving it a market capitalization of about €139. It said that, assuming the full exercise of the overallotment option, it would have 14.68 million shares out, of which 63.6 percent would be held by its major shareholders: Advent Venture Partners, Forbion Capital Partners, Gilde Healthcare Partners, Essential Medical Treatments AG, Crédit Agricole Private Equity and Amsterdam Medical Center. That percentage does not include any increase if those stockholders bought shares in the IPO.

Company officials entered a 360-day lockup period covering their shares, while major shareholders entered into a lockup agreement for 180 days, with further restrictions during the subsequent 180 days.

AMT said it genetically engineers AAV vectors to target various organs or specific tissues, such as muscle or liver, and even specific types of cells within these organs. By combining its AAV-based vectors with different therapeutic genes and tissue-specific promoters, AMT said its platform vector technology is modular in approach and can facilitate fast product design timelines for future products.

The company was founded in 1998 based on discoveries made at the Academic Medical Center in Amsterdam, where the company and its 40 employees remain based.