AMT Receives EMEA Orphan Drug Designation for Acute Intermittent Porphyria

AMSTERDAM — Amsterdam Molecular Therapeutics (Euronext: AMT), a leader in the field of human gene therapy, announced today that the European Medicines Agency has granted Orphan Drug Designation to AMT’s gene therapy product AMT-021 for the treatment of acute intermittent porphyria (AIP).

Orphan Drug Designation for AIP entitles AMT to ten year market exclusivity in Europe following marketing approval for AMT-021 if this product candidate is the first new drug with a major medical benefit receiving marketing approval for the European Union. The designation also provides for special benefits, including research support, eligibility for protocol assistance and possible exemptions or reductions in certain regulatory fees during development or at the time of application for marketing approval.

“We are proud to have received this Orphan Drug Designation for the treatment of acute intermittent porphyria,” said Sander van Deventer, Chief Executive Officer of AMT. “This designation is an important step in the development of a treatment for this seriously debilitating and potentially lethal disease.”

About Acute Intermittent Porphyria

Acute intermittent porphyria is a rare genetic disease in which mutations in the PBGD gene result in insufficient activity of a protein necessary for the synthesis of heme. This leads to an accumulation of toxic intermediate metabolites resulting in a wide variety of problems including acute, severe abdominal pains, psychiatric, neurologic illnesses, and muscular weakness. Long-term consequences may be irreversible nerve damage, liver cancer and kidney failure. Acute porphyric attacks can be life-threatening.

AIP affects 1 per 10.000 people in the European Union.

Currently available therapies do not prevent the symptoms and consequences of acute porphyric attacks. AMT has demonstrated that its product, AMT-021, results in normalization of the PBGD protein in an animal model of AIP. In this model, the therapy completely prevented the occurrence of attacks and significantly ameliorated the neuropathy that develops in untreated mice. AMT-021 is intended to provide long-term normalization of the PBGD protein in order to prevent acute porphyric attacks and their complications.

About Amsterdam Molecular Therapeutics

AMT has a unique gene therapy platform that to date appears to circumvent many if not all of the obstacles that have prevented gene therapy from becoming a mainstay of clinical medicine. Using adeno-associated viral (AAV) vectors as the delivery vehicle of choice for therapeutic genes, the company has been able to design and validate what is probably the first stable and scalable AAV production platform. As such, AMT’s proprietary platform holds tremendous promise for thousands of rare (orphan) diseases, especially those that are caused by one faulty gene. Currently, AMT has a product pipeline with nine products at different stages of development.

Certain statements in this press release are “forward-looking statements” including those that refer to management’s plans and expectations for future operations, prospects and financial condition. Words such as “strategy,” “expects,” “plans,” “anticipates,” “believes,” “will,” “continues,” “estimates,” “intends,” “projects,” “goals,” “targets” and other words of similar meaning are intended to identify such forward-looking statements. Such statements are based on the current expectations of the management of Amsterdam Molecular Therapeutics only. Undue reliance should not be placed on these statements because, by their nature, they are subject to known and unknown risks and can be affected by factors that are beyond the control of AMT. Actual results could differ materially from current expectations due to a number of factors and uncertainties affecting AMT’s business, including, but not limited to, the timely commencement and success of AMT’s clinical trials and research endeavors, delays in receiving U.S. Food and Drug Administration or other regulatory approvals (i.e. EMEA, Health Canada), market acceptance of AMT’s products, effectiveness of AMT’s marketing and sales efforts, development of competing therapies and/or technologies, the terms of any future strategic alliances, the need for additional capital, the inability to obtain, or meet, conditions imposed for required governmental and regulatory approvals and consents. AMT expressly disclaims any intent or obligation to update these forward-looking statements except as required by law. For a more detailed description of the risk factors and uncertainties affecting AMT, refer to the prospectus of AMT’s initial public offering on June 20, 2007, and AMT’s public announcements made from time to time.