Collegium (NASDAQ: COLL) EVP trades 13,976 shares under 10b5-1 plan

Rhea-AI Filing Summary

COLLEGIUM PHARMACEUTICAL, INC. executive vice president and general counsel David Dieter reported an open-market sale of 13,976 shares of common stock on March 18, 2026 at a weighted average price of $34.9241 per share. The sale was made under a pre-arranged Rule 10b5-1 trading plan adopted on December 5, 2025, and executed through multiple trades between $34.74 and $35.39. Following this transaction, Dieter directly holds 77,071 shares of Collegium common stock.

Insider Trade Summary 10b5-1

Net Seller: 13,976 shares ($488,099)

Net Sell 1 txn

Insider Dieter David

Role EVP & General Counsel

Sold 13,976 shs ($488K)

Type	Security	Shares	Price	Value
Sale	Common Stock	13,976	$34.9241	$488K

Holdings After Transaction: Common Stock — 77,071 shares (Direct)

Footnotes (1)

1. The transaction reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 5, 2025. The price reported in column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $34.74 to $35.39, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

X

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Dieter David

(Last) (First) (Middle)

C/O COLLEGIUM PHARMACEUTICAL, INC.

100 TECHNOLOGY CENTER DRIVE

(Street)

STOUGHTON MASSACHUSETTS 02072

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
COLLEGIUM PHARMACEUTICAL, INC [ COLL ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP & General Counsel

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
03/18/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	03/18/2026		S(1)		13,976	D	$34.9241(2)	77,071	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. The transaction reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 5, 2025.

2. The price reported in column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $34.74 to $35.39, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

	/s/ Colleen Tupper as Attorney-In-Fact For Scott Dreyer	03/20/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transaction did COLLEGIUM PHARMACEUTICAL (COLL) report for David Dieter?

COLLEGIUM PHARMACEUTICAL reported that EVP and general counsel David Dieter sold 13,976 shares of common stock. The open-market sale occurred on March 18, 2026, at a weighted average price of $34.9241 per share, as disclosed in a Form 4 insider filing.

At what price did COLLEGIUM PHARMACEUTICAL (COLL) executive David Dieter sell his shares?

David Dieter’s sale was reported at a weighted average price of $34.9241 per share. The shares were sold in multiple transactions, with individual trade prices ranging from $34.74 to $35.39, according to detailed pricing information included in the Form 4 footnotes.

How many COLLEGIUM PHARMACEUTICAL (COLL) shares does David Dieter hold after the reported sale?

After the reported transaction, David Dieter directly holds 77,071 shares of COLLEGIUM PHARMACEUTICAL common stock. This post-transaction balance reflects the completion of his 13,976-share open-market sale disclosed in the Form 4 insider trading report filed with regulators.

Was the COLLEGIUM PHARMACEUTICAL (COLL) insider sale made under a Rule 10b5-1 trading plan?

Yes. The Form 4 states the sale was effected pursuant to a Rule 10b5-1 trading plan adopted by David Dieter on December 5, 2025. Such plans pre-schedule trades, helping separate routine portfolio management from discretionary timing decisions by company insiders.

What type of Form 4 transaction did COLLEGIUM PHARMACEUTICAL (COLL) disclose for David Dieter?

The filing classifies the transaction as an open-market sale of non-derivative common stock, coded “S” on Form 4. This indicates a direct sale of existing shares rather than an option exercise, tax withholding event, or derivative conversion transaction by the reporting executive.