Collegium to Acquire AZSTARYS from Corium Therapeutics, Strengthening Position in ADHD and Accelerating Growth Trajectory - Adds Highly Complementary and Differentiated Medicine with Significant Growth Potential to Colle

Collegium to Acquire AZSTARYS from Corium

Therapeutics, Strengthening Position in ADHD and Accelerating Growth Trajectory

- Adds Highly Complementary and Differentiated

Medicine with Significant Growth Potential to Collegium's Existing ADHD Portfolio -

- Enables Greater Impact Across ADHD Patient

- AZSTARYS Expected to Generate Over $50

Million in Second Half 2026 Pro Forma Net Revenue -

- Expected Patent Protection into 2037

- Transaction Expected to be Immediately

Accretive to Adjusted EBITDA -

- Acquisition to Be Funded by Collegium's

Cash on Hand and Previously Announced $300 Million Delayed Draw Term Loan -

- Conference Call Scheduled for Today

STOUGHTON and CAMBRIDGE, Mass., March 19, 2026

-- Collegium Pharmaceutical, Inc. (Nasdaq: COLL) and Corium Therapeutics Holdings, LLC (Corium Therapeutics), today announced a definitive

agreement pursuant to which Collegium will acquire AZSTARYS for $650 million in cash with the potential for additional milestone payments

up to $135 million depending on future commercial and regulatory milestones.

Corium Therapeutics is a privately held company

that, through its subsidiaries, markets and distributes AZSTARYS (serdexmethylphenidate and dexmethylphenidate), a central nervous system

(CNS) stimulant prescription medicine used for the treatment of Attention Deficit Hyperactivity Disorder (ADHD) in people 6 years of age

and older. It is the first and only ADHD treatment with both immediate release and long-acting medicines in one capsule. The acquisition

of AZSTARYS is expected to significantly strengthen Collegium's position in ADHD, further diversifying and bolstering its revenue

"The acquisition of AZSTARYS marks a highly

strategic addition to our product portfolio - one that accelerates our growth trajectory while reinforcing our long-standing commitment

to improving patient care and delivering shareholder value," said Vikram Karnani, President and Chief Executive Officer. "The

addition of AZSTARYS will significantly complement our existing ADHD business while extending revenues into 2037 and beyond. Healthcare

providers view both JORNAY PM and AZSTARYS as differentiated medicines that each play an important role in addressing

the unmet needs of people with ADHD. This immediately accretive transaction meaningfully advances our ambition to build a leading, diversified

biopharmaceutical company."

"Over the past two years, our team has worked

hard to establish AZSTARYS as a leading treatment option for patients with ADHD through innovative patient access solutions and analytically

driven execution," said Todd Smith, Chief Executive Officer of Corium Therapeutics. "We are proud of the progress that has

been achieved and believe Collegium is well positioned to build on that foundation and continue expanding its reach."

Transaction Rationale

Additional Transaction Details

The transaction, which has been unanimously approved by the boards

of directors of both companies, is expected to close in the second quarter of 2026, subject to customary closing conditions, including

receipt of required regulatory and Hart-Scott-Rodino approvals.

Leerink Partners is acting as the exclusive financial advisor to Collegium.

Centerview Partners is acting as the exclusive financial advisor to Corium Therapeutics. Goodwin Proctor LLP is serving as M&A legal

counsel to Collegium. Sullivan & Cromwell LLP is serving as M&A legal counsel to Corium Therapeutics.

Conference Call Information

The Company will host a conference call and live audio webcast today,

March 19, 2026, at 9:00 a.m. ET. To access the conference call, please dial (877) 407-8037 (U.S.) or (201) 689-8037 (International) and

reference the "Collegium Pharmaceutical Investor Conference Call." An audio webcast will be accessible from the Investors

section of the Company's website: www.collegiumpharma.com. The webcast will be available for replay on the Company's website

approximately two hours after the event.

About Collegium Pharmaceutical, Inc.

Collegium is building a leading,

diversified biopharmaceutical company committed to improving the lives of people living with serious medical conditions. The Company

has a leading portfolio of responsible pain management medications and a rapidly growing neuropsychiatry business driven by JORNAY

PM , a differentiated treatment for ADHD. Collegium's strategy includes growing

its commercial portfolio, with JORNAY PM as the lead growth driver, and deploying capital

in a disciplined manner. Collegium's headquarters are located in Stoughton, Massachusetts. For more information, please

visit the Company's website at www.collegiumpharma.com.

Non-GAAP Financial Measures

To supplement our financial results presented

on a GAAP basis, we have included information about certain non-GAAP financial measures. We believe the presentation of these non-GAAP

financial measures, when viewed with our results under GAAP and the accompanying reconciliations, provide analysts, investors, lenders,

and other third parties with insights into how we evaluate normal operational activities, including our ability to generate cash from

operations, on a comparable year-over-year basis and manage our budgeting and forecasting. In addition, certain non-GAAP financial measures,

primarily adjusted EBITDA, are used to measure performance when determining components of annual compensation for substantially all non-sales

force employees, including senior management.

In this press release we discuss the following financial measures that

are not calculated in accordance with GAAP.

Adjusted EBITDA is a non-GAAP financial measure

that represents GAAP net income or loss adjusted to exclude interest expense, interest income, the benefit from or provision for income

taxes, depreciation, amortization, stock-based compensation, and other adjustments to reflect changes that occur in our business but do

not represent ongoing operations. Adjusted EBITDA, as used by us, may be calculated differently from, and therefore may not be comparable

to, similarly titled measures used by other companies.

There are several limitations related to the use

of adjusted EBITDA rather than net income or loss, which is the nearest GAAP equivalent, such as:

The Company has not provided a reconciliation

of its full-year 2026 guidance for adjusted EBITDA to the most directly comparable forward-looking GAAP measures, in reliance on the unreasonable

efforts exception provided under Item 10(e)(1)(i)(B) of Regulation S-K, because the Company is unable to predict, without unreasonable

efforts, the timing and amount of items that would be included in such a reconciliation, including, but not limited to, stock-based compensation

expense, acquisition related expenses, amortization of acquired intangible assets, and changes in fair value of contingent consideration.

These items are uncertain and depend on various factors that are outside of the Company's control or cannot be reasonably predicted.

While the Company is unable to address the probable significance of these items, they could have a material impact on GAAP net income

and operating expenses for the guidance period. A reconciliation of adjusted EBITDA would imply a degree of precision and certainty as

to these future items that does not exist and could be confusing to investors.

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 "predicts,"

"forecasts," "believes," "potential," "proposed," "continue," "estimates,"

"anticipates," "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 the expected closing of the

transaction; the anticipated benefits of the acquisition of AZSTARYS, including its impact

on Collegium's ADHD portfolio and commercial strategy; projected financial performance, including expected revenue and adjusted

EBITDA, and other statements that are not historic facts. 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, including

risks relating to, among others: risks related to our ability to complete the transaction on the proposed terms and schedule or at all;

the failure (or delay) to receive the required regulatory approvals relating to the transaction; risks related to our ability to realize

the anticipated benefits of the proposed acquisition, including the possibility that the expected benefits from the acquisition will not

be realized or will not be realized within the expected time period; the risk that the businesses will not be integrated successfully;

disruption from the transaction making it more difficult to maintain business and operational relationships; negative effects of this

announcement or the consummation of the proposed acquisition on the market price of our common stock and/or operating results; risks related

to significant transaction costs or the acquisition of unknown liabilities; the risk of litigation and/or regulatory actions related to

the proposed acquisition; risks related to future opportunities and plans for AZSTARYS, including