Omeros insider plans $464K sale of 25,000 shares

Omeros Corporation (OMER) insider Peter Brogan Cancelmo has filed a Rule 144 notice for a proposed sale of 25,000 shares of Omeros common stock through Morgan Stanley Smith Barney.

Rhea-AI Filing Summary

Omeros Corporation (OMER) insider Peter Brogan Cancelmo has filed a Rule 144 notice for a proposed sale of 25,000 shares of Omeros common stock through Morgan Stanley Smith Barney. The shares relate to an exercise of options under a registered plan, with an aggregate market value listed as $463,540. Omeros common shares outstanding are reported as 72,388,316 as of the notice date. The notice also lists a prior sale of 25,000 shares for $466,127.50 within the past three months.

Key Figures

Shares proposed to be sold: 25,000 shares of common stock Aggregate market value of proposed sale: $463,540 Shares outstanding: 72,388,316 shares +3 more

6 metrics

Shares proposed to be sold 25,000 shares of common stock Rule 144 notice for planned sale around 08/31/2026

Aggregate market value of proposed sale $463,540 Value of 25,000 shares listed in the notice

Shares outstanding 72,388,316 shares Omeros common shares outstanding as of the notice date

Prior 3-month sale shares 25,000 shares Sale by Peter Cancelmo on 08/28/2026

Prior 3-month sale proceeds $466,127.50 Aggregate proceeds from 25,000-share sale on 08/28/2026

Option exercise acquisition date 08/31/2026 Date of acquisition via exercise of options under a registered plan

Key Terms

Rule 144, Exercise of Options Under a Registered Plan, Aggregate market value, Securities To Be Sold, +1 more

5 terms

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

"Exercise of Options Under a Registered Plan | Issuer | | | 25000"

Aggregate market value financial

"| 25000 | 463540.00 | 72388316 | 08/31/2026 |"

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.

Securities To Be Sold regulatory

"144: Securities To Be Sold Common | 08/31/2026 | Exercise of Options"

Securities Sold During The Past 3 Months regulatory

"144: Securities Sold During The Past 3 Months PETER CANCELMO"

FAQ

What insider transaction did OMER disclose in this Form 144 notice?

The notice states that Peter Brogan Cancelmo plans a Rule 144 sale of 25,000 shares of Omeros common stock, related to an exercise of options under a registered plan, with a listed aggregate market value of $463,540.

How many OMER shares are proposed to be sold under Rule 144?

The Rule 144 notice covers a proposed sale of 25,000 shares of Omeros Corporation common stock, with the transaction indicated to occur on or about 08/31/2026.

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

The aggregate market value for the proposed sale of 25,000 Omeros common shares is listed as approximately $463,540 in the Rule 144 notice.

How many OMER shares are outstanding according to this notice?

The notice reports that Omeros Corporation has 72,388,316 shares of common stock outstanding as of the notice date; this is a baseline figure, not the amount being sold.

Were any OMER shares sold by this person in the past three months?

Yes. The notice lists a prior sale by Peter Cancelmo of 25,000 shares of Omeros common stock on 08/28/2026 for total proceeds of $466,127.50.

How were the OMER shares to be sold acquired by the insider?

The shares covered by the notice are indicated as acquired via "Exercise of Options Under a Registered Plan", with payment described as cash to the issuer on 08/31/2026.

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

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Available on EDGAR 08/31/2026 - 04:22 PM Accepted by SEC EDGAR 08/31/2026 - 04:21 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	463540.00	72388316	08/31/2026	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	08/31/2026	Exercise of Options Under a Registered Plan	Issuer			25000	08/31/2026	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

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
PETER CANCELMO 201 Elliott Avenue West Seattle WA 98119	Common	08/28/2026	25000	466127.50

144: Remarks and Signature

Remarks
Date of Notice	08/31/2026
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)