OrbiMed lists multiple Common Stock resales

OrbiMed Private Investments VIII, LP reported proposed sales of Common Stock in an amended Form 144/A, listing multiple share dispositions between 04/14/2026 and 05/27/2026.

Rhea-AI Filing Summary

OrbiMed Private Investments VIII, LP reported proposed sales of Common Stock in an amended Form 144/A, listing multiple share dispositions between 04/14/2026 and 05/27/2026. The amendment itemizes individual transactions, including sales of 235,863 shares for $10,528,924.32 on 04/15/2026 and 184,639 shares for $8,534,014.58 on 05/11/2026.

Insights

Securities Compliance Counsel

Amendment lists specific resale trades by an affiliate across April–May 2026.

The filing is an amended Form 144 reporting multiple block dispositions of Common Stock by OrbiMed Private Investments VIII, LP, with per-trade share counts and gross proceeds shown for each date between 04/14/2026 and 05/27/2026.

These entries are routine resale notices required when affiliates intend to sell; cash-flow treatment and whether sales were via block trades or other methods are not specified in the excerpt. Subsequent public filings or trade reports would show execution details.

Key Figures

Sale on 04/15/2026: 235,863 shares Sale on 05/11/2026: 184,639 shares Sale on 04/16/2026: 226,906 shares +2 more

5 metrics

Sale on 04/15/2026 235,863 shares reported on Form 144/A with proceeds of $10,528,924.32

Sale on 05/11/2026 184,639 shares reported on Form 144/A with proceeds of $8,534,014.58

Sale on 04/16/2026 226,906 shares reported with proceeds of $10,287,918.04

Sale on 04/15/2026 (alternate line) 47,814 shares reported on 04/14/2026 line with proceeds of $2,128,201.44

Sale on 05/27/2026 101 shares reported with proceeds of $4,493.49

Key Terms

Form 144/A, resale, affiliate selling holder

3 terms

Form 144/A regulatory

"Amended Form 144/A reporting proposed sales of Common Stock"

resale financial

"Securities To Be Sold — Common Stock — IPO — Issuer — Cash"

Resale is the act of selling an item, asset, or security by someone who previously bought it rather than by the original maker or issuer. It matters to investors because resale activity affects how easily an investment can be sold, the price buyers are willing to pay, and the potential profit or loss — like selling a used car: condition, demand and market rules determine what you can get for it.

affiliate selling holder regulatory

"OrbiMed Private Investments VIII, LP listed as selling holder"

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What does SION's Form 144/A amendment disclose?

Direct answer: The amendment lists proposed/resale sales of Common Stock by OrbiMed Private Investments VIII, LP with dates and per-trade amounts. Context: It itemizes individual transactions between 04/14/2026 and 05/27/2026, showing shares and gross proceeds for each trade.

How many shares did OrbiMed sell on 04/15/2026 in the filing?

Direct answer: The filing shows a sale of 235,863 shares on 04/15/2026. Context: The same line reports gross proceeds of $10,528,924.32 associated with that transaction.

What are the largest individual trades listed in the amendment?

Direct answer: The amendment includes large individual trades such as 235,863 shares (04/15/2026) and 184,639 shares (05/11/2026). Context: Each trade line shows the share count and corresponding gross dollar amount.

Does the Form 144/A state how proceeds will be used?

Direct answer: The excerpt does not state any use of proceeds. Context: The entries list share counts, dates, and gross proceeds for each trade but do not describe recipients beyond the selling holder or uses of cash.

Which dates span the sales reported in the amendment?

Direct answer: The listed transactions occur between 04/14/2026 and 05/27/2026. Context: Multiple daily entries show discrete share dispositions and corresponding gross proceeds across that period.

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

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google Not now

Accepted by SEC EDGAR 06/01/2026 - 12:39 PM EDT 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/A

144/A: Filer Information

Filer CIK	0001055951
Filer CCC	XXXXXXXX
Previous Accession Number Of The Filing	0000947871-26-000586
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144/A: Issuer Information

Name of Issuer	Sionna Therapeutics, Inc.
SEC File Number	001-42504
Address of Issuer	21 HICKORY DRIVE SUITE 500 WALTHAM MASSACHUSETTS 02451
Phone	617-819-2020
Name of Person for Whose Account the Securities are To Be Sold	OrbiMed Private Investments VIII, LP
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	Shareholder

144/A: 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 Stock	TD Cowen 599 Lexington Avenue New York NY 10022	210876	9029710.32	45150330	05/29/2026	Nasdaq Stock Market

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/A: 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 Stock	02/10/2025	IPO	Issuer			210876	02/10/2025	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/A: 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
OrbiMed Private Investments VIII, LP 601 Lexington Ave. 54th Floor New York NY 10022	Common Stock	04/14/2026	47814	2128201.44
OrbiMed Private Investments VIII, LP 601 Lexington Ave. 54th Floor New York NY 10022	Common Stock	04/15/2026	235863	10528924.32
OrbiMed Private Investments VIII, LP 601 Lexington Ave. 54th Floor New York NY 10022	Common Stock	04/16/2026	226906	10287918.04
OrbiMed Private Investments VIII, LP 601 Lexington Ave. 54th Floor New York NY 10022	Common Stock	04/17/2026	52397	2341097.96
OrbiMed Private Investments VIII, LP 601 Lexington Ave. 54th Floor New York NY 10022	Common Stock	04/20/2026	2948	131244.96
OrbiMed Private Investments VIII, LP 601 Lexington Ave. 54th Floor New York NY 10022	Common Stock	05/07/2026	48546	2165637.06
OrbiMed Private Investments VIII, LP 601 Lexington Ave. 54th Floor New York NY 10022	Common Stock	05/08/2026	59767	2664412.86
OrbiMed Private Investments VIII, LP 601 Lexington Ave. 54th Floor New York NY 10022	Common Stock	05/11/2026	184639	8534014.58
OrbiMed Private Investments VIII, LP 601 Lexington Ave. 54th Floor New York NY 10022	Common Stock	05/27/2026	101	4493.49

144/A: Remarks and Signature

Remarks	OrbiMed Capital GP VIII LLC is the general partner of OrbiMed Private Investments VIII, LP. OrbiMed Advisors LLC is the managing member of OrbiMed Capital GP VIII LLC.
Date of Notice	06/01/2026
Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1	02/10/2025
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/ Douglas Coon, Chief Compliance Officer, OrbiMed Advisors LLC, managing member of the general partner of OrbiMed Private Investments VIII, LP
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)