Omeros holder plans $466K sale of 25,000 shares

OMEROS CORP (OMER) received a Form 144 notice from Peter Brogan Cancelmo covering a proposed sale of up to 25,000 shares of common stock.

Rhea-AI Filing Summary

OMEROS CORP (OMER) received a Form 144 notice from Peter Brogan Cancelmo covering a proposed sale of up to 25,000 shares of common stock. The shares are to be sold through Morgan Stanley Smith Barney LLC, in connection with the exercise of options under a registered plan for cash, with a proposed sale date of August 28, 2026.

Key Figures

Shares of common stock to be sold: 25,000 shares Aggregate market value of securities to be sold: $466,127.50 Proposed sale date: 08/28/2026

3 metrics

Shares of common stock to be sold 25,000 shares Proposed sale by Peter Brogan Cancelmo under Rule 144

Aggregate market value of securities to be sold $466,127.50 Value stated for the 25,000 OMEROS CORP common shares

Proposed sale date 08/28/2026 Date listed for the sale of OMEROS CORP common stock

Key Terms

Form 144, Rule 144, Exercise of Options Under a Registered Plan, Aggregate market value

4 terms

Form 144 regulatory

"144: Filer Information"

Form 144 is a document that investors must file with the government when they plan to sell a large number of shares of a company's stock. It helps ensure transparency so everyone knows how many shares are being sold and when, which can impact the stock's price.

Rule 144 regulatory

"See the definition of "person" in paragraph (a) of Rule 144."

Rule 144 is a U.S. securities regulation that sets conditions under which restricted or insider-held shares can be legally resold to the public, such as required holding periods, availability of public information, limits on how much can be sold at once, and certain filing requirements. For investors it matters because it determines when previously locked-up shares can enter the market — like a release valve that can increase supply, affect share price, and signal insider intent.

Exercise of Options Under a Registered Plan financial

"Common | 08/28/2026 | Exercise of Options Under a Registered Plan | Issuer"

Aggregate market value financial

"Common | Morgan Stanley Smith Barney LLC ... | 25000 | 466127.50"

Aggregate market value is the combined price you would pay to buy all outstanding shares of a company or all companies in a group at current market prices — essentially the sum of each stock’s market capitalization. It matters to investors because it shows the overall size and weight of an investment or sector (like the total cost to buy every piece of a puzzle), helps compare scale across companies or markets, and influences index composition and risk exposure.

FAQ

What does the Form 144 filing for OMER (OMEROS CORP) disclose?

The filing discloses that Peter Brogan Cancelmo has filed a notice to sell up to 25,000 shares of OMEROS CORP common stock under Rule 144, related to the exercise of options under a registered plan, with a proposed sale date of August 28, 2026.

How many OMER (OMEROS CORP) shares are covered by this Form 144?

The notice covers up to 25,000 shares of OMEROS CORP common stock proposed to be sold by Peter Brogan Cancelmo in connection with the exercise of stock options under a registered plan.

What is the aggregate market value of the OMER shares in this Form 144?

The Form 144 states an aggregate market value of $466,127.50 for the 25,000 shares of OMEROS CORP common stock proposed to be sold.

When are the OMER (OMEROS CORP) shares proposed to be sold under this Form 144?

The shares are proposed to be sold on or about August 28, 2026, as indicated in the Form 144 for OMEROS CORP.

Through which broker will the OMER shares be sold according to the Form 144?

The Form 144 lists Morgan Stanley Smith Barney LLC Executive Financial Services, located at 1 New York Plaza, New York, as the broker for the proposed sale of OMEROS CORP common stock.

What is the source of the OMER shares to be sold in this Form 144?

The filing states that the OMEROS CORP common shares are to be sold upon exercise of options under a registered plan, with the transaction to be settled in cash.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 08/28/2026 - 04:35 PM Accepted by SEC EDGAR 08/28/2026 - 04:34 PM Learn about SEC filing dates

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0001778968
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	OMEROS CORPORATION
SEC File Number	001-34475
Address of Issuer	201 Elliott Avenue West Seattle WASHINGTON 98119
Phone	206-676-5000
Name of Person for Whose Account the Securities are To Be Sold	PETER CANCELMO
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Officer

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common	Morgan Stanley Smith Barney LLC Executive Financial Services 1 New York Plaza 8th Floor New York NY 10004	25000	466127.50	72388316	08/28/2026	NASDAQ

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common	08/28/2026	Exercise of Options Under a Registered Plan	Issuer			25000	08/28/2026	Cash

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Nothing to Report

144: Remarks and Signature

Remarks
Date of Notice	08/28/2026
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	/s/ Peter Brogan Cancelmo
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)