ASND gets FDA major amendment, new TransCon CNP PDUFA timeline

Rhea-AI Filing Summary

Ascendis Pharma A/S reports that the U.S. Food and Drug Administration has classified new information it submitted on November 5, 2025 for TransCon CNP (navepegritide) as a major amendment to its New Drug Application for treating children with achondroplasia. Because of this, the FDA has extended the PDUFA target action date by three months to February 28, 2026. This change gives the FDA more time to complete its ongoing review before deciding on the application.

Insights

Biopharma regulatory analyst

FDA extended TransCon CNP’s review by three months to February 28, 2026.

Ascendis Pharma received notice that additional information submitted on November 5, 2025 for TransCon CNP was deemed a major amendment to its New Drug Application for children with achondroplasia. Under PDUFA rules, this reclassification extends the FDA’s decision timeline, moving the target action date to February 28, 2026.

The extension indicates regulators want more time to assess the new material, but it does not by itself signal a positive or negative outcome. The company highlights typical risks, such as dependence on third parties, potential unforeseen safety or efficacy findings, and possible delays related to manufacturing or patient recruitment.

The key milestone now is the revised PDUFA target action date of February 28, 2026 for the TransCon CNP NDA. Subsequent company reports may provide further detail on the review status and any additional regulatory interactions.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO SECTION 13a-16 OR 15d-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of November, 2025

Commission File Number: 001-36815

Ascendis Pharma A/S

(Exact Name of Registrant as Specified in Its Charter)

Tuborg Boulevard 12

DK-2900 Hellerup

Denmark

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F ☒    Form 40-F ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): ☐

INCORPORATION BY REFERENCE

This report on Form 6-K shall be deemed to be incorporated by reference into the registration statements on Form S-8 (Registration Numbers 333-203040, 333-210810, 333-211512, 333-213412, 333-214843, 333-216883, 333-228576, 333-254101, 333-261550, 333-270088, 333-277519, 333-281916 and 333-285322) and Form F-3 (Registration Numbers 333-209336, 333-211511, 333-216882, 333-223134, 333-225284, 333-256571 and 333-282196) of Ascendis Pharma A/S (the “Company” or “Ascendis”) (including any prospectuses forming a part of such registration statements) and to be a part thereof from the date on which this report is filed, to the extent not superseded by documents or reports subsequently filed or furnished.

On November 25, 2025, the Company announced that the U.S. Food and Drug Administration (“FDA”) notified the Company that information submitted on November 5, 2025, related to the post-marketing requirement in response to the FDA’s ongoing review of the New Drug Application (“NDA”) for TransCon CNP (navepegritide) for children with achondroplasia constituted a major amendment to the NDA. Accordingly, the FDA has extended the Prescription Drug User Fee Act (“PDUFA”) target action date by three months to February 28, 2026.

Forward-Looking Statements

This report contains forward-looking statements that involve substantial risks and uncertainties. All statements, other than statements of historical facts, included in this report regarding Ascendis’ future operations, plans and objectives of management are forward-looking statements, including the statement relating to the PDUFA target action date for the NDA for TransCon CNP for children with achondroplasia. Ascendis may not actually achieve the plans, carry out the intentions or meet the expectations or projections disclosed in the forward-looking statements and you should not place undue reliance on these forward-looking statements. Actual results or events could differ materially from the plans, intentions, expectations and projections disclosed in the forward-looking statements. Various important factors could cause actual results or events to differ materially from the forward-looking statements that Ascendis makes, including the following: dependence on third party manufacturers, distributors and service providers for Ascendis’ products and product candidates; unforeseen safety or efficacy results in Ascendis’ development programs or on-market products; unforeseen expenses related to commercialization of any approved Ascendis products; unforeseen expenses related to Ascendis’ development programs; unforeseen selling, general and administrative expenses, other research and development expenses and Ascendis’ business generally; delays in the development of its programs related to manufacturing, regulatory requirements, speed of patient recruitment or other unforeseen delays; Ascendis’ ability to obtain additional funding, if needed, to support its business activities; and the impact of international economic, political, legal, compliance, social and business factors, including tariffs and trade policies. For a further description of the risks and uncertainties that could cause actual results to differ from those expressed in these forward-looking statements, as well as risks relating to Ascendis’ business in general, see Ascendis’ Annual Report on Form 20-F filed with the U.S. Securities and Exchange Commission (“SEC”) on February 12, 2025, and Ascendis’ other future reports filed with, or submitted to, the SEC. Forward-looking statements do not reflect the potential impact of any future licensing, collaborations, acquisitions, mergers, dispositions, joint ventures, or investments that Ascendis may enter into or make. Ascendis does not assume any obligation to update any forward-looking statements, except as required by law.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

				Ascendis Pharma A/S
Date: November 25, 2025				By:		/s/ Michael Wolff Jensen
						Michael Wolff Jensen
						Executive Vice President, Chief Legal Officer

FAQ

What did Ascendis Pharma (ASND) announce regarding TransCon CNP?

Ascendis Pharma announced that the FDA classified new information submitted on November 5, 2025 for TransCon CNP (navepegritide) as a major amendment to its New Drug Application for treating children with achondroplasia.

How did the FDA’s decision affect the PDUFA date for Ascendis Pharma (ASND)?

The FDA’s major amendment determination extended the PDUFA target action date for the TransCon CNP NDA by three months to February 28, 2026, giving regulators more time to complete their review.

What is TransCon CNP in Ascendis Pharma’s (ASND) pipeline?

TransCon CNP (navepegritide) is a product candidate under FDA review as a treatment for children with achondroplasia, a genetic form of dwarfism.

Does the PDUFA extension indicate the FDA’s view on TransCon CNP for Ascendis Pharma (ASND)?

The extension reflects that the FDA treated the new submission as a major amendment and therefore extended the review timeline. The company states that actual results or events could differ materially from expectations, and the filing does not describe the extension as either favorable or unfavorable for approval.

What key risks does Ascendis Pharma (ASND) highlight in this update?

Ascendis notes risks including reliance on third-party manufacturers and distributors, potential unforeseen safety or efficacy results, unexpected commercialization and development expenses, delays related to manufacturing or regulatory requirements, funding needs, and broader international economic and political factors.

How is this Form 6-K used in Ascendis Pharma’s (ASND) SEC registration statements?

This report is incorporated by reference into Ascendis Pharma’s existing Form S-8 and Form F-3 registration statements, meaning the information becomes part of those registration documents from the date of filing.