Proteostasis Therapeutics Announces Collaboration with Biogen Idec for Research, Development and Commercialization of Therapies for Neurodegenerative Diseases

Proteostasis Therapeutics, Inc., a company developing novel therapeutics that regulate protein homeostasis aimed at helping to improve outcomes for patients with orphan and neurodegenerative diseases, today announced that it has entered into a worldwide collaboration with Biogen Idec (NASDAQ: BIIB) to research and develop therapeutic candidates based on the inhibition of Usp14. This collaboration combines Proteostasis Therapeutics' proprietary scientific platform and preclinical work on protein degradation with Biogen Idec's neurodegenerative disease research and clinical development capabilities.

"We are very pleased to be collaborating with Biogen Idec, a worldwide leader in the innovative treatment of neurodegenerative diseases," said Markus Haeberlein, MSc, Ph.D., Senior Vice President and Head of Research at Proteostasis Therapeutics. "We look forward to advancing our disease-modifying approach to develop therapeutic candidates that can address several protein aggregation disorders, including Parkinson's and Alzheimer's disease."

Preclinical research has shown that the inhibition of Usp14, a deubiquitinating enzyme, modulates proteasome activity and increases the degradation rate of aggregation-prone proteins, including ?-synuclein in Parkinson's disease and tau in Alzheimer's disease. The collaboration is intended to develop Usp14 inhibitors as a disease-modifying approach for a wide range of disorders involving toxic protein aggregation.

"Proteostasis is a leader in this field, and we are pleased to be working with them to develop meaningful new treatments for patients with neurodegenerative and other diseases," said Spyros Artavanis-Tsakonas, Ph.D., Chief Scientific Officer at Biogen Idec.

Proteostasis will receive an initial upfront payment from Biogen Idec, along with an equity investment, and is eligible for research funding support and future development and commercial milestones that could result in total payments of up to $200 million, as well as tiered royalties. Under the agreement, the companies will conduct preclinical research to identify lead compounds for clinical development. At specified points in development, Proteostasis will have the option to receive potential milestones or opt in for global co-development and U.S. co-commercialization rights.

The Usp14 technology was originally developed at Harvard Medical School by Professors Daniel Finley, Ph.D., and Randall King, Ph.D., M.D., both members of the Proteostasis Scientific Advisory Board, and funded in part by the Blavatnik Biomedical Accelerator program. It is being advanced under license from Harvard University.

About Proteostasis Therapeutics

Proteostasis Therapeutics is developing disease-modifying therapeutics for orphan and neurodegenerative diseases with lead programs in cystic fibrosis and a collaboration with Biogen Idec to develop therapeutics for neurodegenerative diseases. The Company's platform revolves around the modulation of protein homeostasis pathways within the cell. These pathways are part of the cellular 'quality control' machinery, called the protein homeostasis network or Proteostasis Network (PN) that regulates protein folding, trafficking, and clearance. By modifying the function and capacity of the PN, the Company's product candidates correct for imbalances in the PN resulting from the cumulative effects of disease, genetic mutations, environmental factors, and aging. For more information, please visit www.proteostasis.com.

Investors:
Stern Investor Relations, Inc.
Jesse Baumgartner, 212-362-1200