Appeals Court Upholds PTAB’s Finding of Invalidity of Purdue’s 961 Patent

Collegium Pharmaceutical, Inc. (Nasdaq: COLL), a leading, diversified specialty pharmaceutical company, today announced that the U.S. Court of Appeals for the Federal Circuit has upheld the judgment of the Patent Trial and Appeal Board (PTAB) in its final decision that Purdue’s ‘961 patent, which Purdue has claimed is infringed by Xtampza® ER, is invalid.

The Federal Circuit’s decision affirming the invalidity of Purdue’s ‘961 patent confirms both that the PTAB had statutory authority to issue its final decision, and that the PTAB did correctly conclude that the ʼ961 patent was invalid.

“We applaud the Federal Circuit’s decision to confirm the authority of the PTAB and uphold its finding of invalidity of Purdue’s patent,” said Shirley Kuhlmann, Chief Administrative Officer and General Counsel of Collegium. “We will continue to vigorously defend Collegium's intellectual property against claims of infringement.”

About Collegium Pharmaceutical, Inc.

Collegium is a leading, diversified specialty pharmaceutical company committed to improving the lives of people living with serious medical conditions. Collegium’s headquarters are located in Stoughton, Massachusetts. For more information, please visit the Company’s website at www.collegiumpharma.com.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. We may, in some cases, use terms such as "believes," "potential," "expects," "plans," "intends," "may," "could," "might," "should" or other words that convey uncertainty of future events or outcomes to identify these forward-looking statements. Examples of forward-looking statements contained in this press release include, among others, statements related to our expectations relating to the timing and outcome of patent litigation. Such statements are subject to numerous important factors, risks and uncertainties that may cause actual events or results, performance, or achievements to differ materially from the company’s current expectations. Actual results may differ materially from management’s expectations and such forward-looking statements in this press release could be affected as a result of various important factors, including risks relating to, among others, the outcome of any current or future patent infringement litigation that may be brought by or against us. These and other risks are described under the heading "Risk Factors" in our Annual Reports on Form 10-K and Quarterly Reports on Form 10-Q and other filings with the SEC. Any forward-looking statements that we make in this press release speak only as of the date of this press release. We assume no obligation to update our forward-looking statements whether as a result of new information, future events or otherwise, after the date of this press release.

Investor Contact:Christopher James, M.D.                                                                                       Vice President, Investor [e-mail]

Media Contact:Marissa SamuelsVice President, Corporate [e-mail]