The law firm of Kessler Topaz Meltzer & Check, LLP informs investors that the firm has filed a securities fraud class action lawsuit against Avantor, Inc. (NYSE: AVTR) (“Avantor” or the “Company”) on behalf of investors who purchased or acquired Avantor common stock between March 5, 2024, and October 28, 2025, inclusive (the “Class Period”). This action, captioned Building Trades Pension Fund of Western Pennsylvania v. Avantor, Inc., et al., Case No. 2:25-cv-06187, was filed in the United States District Court for the Eastern District of Pennsylvania.

Important Deadline Reminder: Investors who purchased or otherwise acquired Avantor common stock during the Class Period may, no later than December 29, 2025, move the Court to serve as lead plaintiff for the class.

CONTACT KESSLER TOPAZ MELTZER & CHECK, LLP:

If you suffered Avantor losses, you may CLICK HERE or copy and paste the following link into your browser: www.ktmc.com/new-cases/avantor-inc?utm_source=Businesswire&mktm=PR

You can also contact attorney Jonathan Naji, Esq. by calling (484) 270-1453 or by email at info@ktmc.com.

DEFENDANTS’ ALLEGED MISCONDUCT

Avantor, a Delaware corporation with its principal executive offices in Radnor, Pennsylvania, provides scientific products and services for customers in biotechnology, pharmaceuticals, healthcare, education, government, and other industries.

The Class Period begins on March 5, 2024, when Defendant Michael Stubblefield, then the Company’s President and Chief Executive Officer, represented Avantor at a TD Cowen healthcare industry conference. In response to an analyst’s question about Avantor’s competitive positioning in its Laboratory Solutions business, Stubblefield emphasized that Avantor’s competitive position “[c]ontinues to be strong,” further representing that “we continue to have confidence in the positioning [of] a lot of investments in our digital capabilities there to make it more efficient for our customers to engage with us…” and that “the traffic to our sites relative to our competitors is a nice indicator for our business.”

During the Class Period, Defendants misled investors by falsely touting the Company’s competitive positioning and downplaying the effects of increased competition. For example, during an earnings call on July 26, 2024, in response to an analyst’s question about whether Avantor was losing share to a competitor, Defendant Stubblefield, assured investors that Avantor’s “lab business stacks up well against every number that certainly that we’ve seen,” that “we continue to enhance our position,” and that “we’re really confident in our value proposition and our competitive position.” Likewise, Defendants repeatedly pointed to Avantor’s purported competitive advantages, such as its digital capabilities, as evidence that the Company would continue to enjoy strong competitive positioning.

Investors began to learn the truth about the effects of increased competition on Avantor’s business on April 25, 2025, when the Company reported disappointing first quarter 2025 financial results, cut its guidance for 2025, and announced that Defendant Stubblefield would be stepping down from his roles as President and Chief Executive Officer. Defendants attributed Avantor’s weak performance and outlook to “the impact of increased competitive intensity.” On this news, the price of Avantor common stock declined $2.57 per share, or more than 16.5%, from a close of $15.50 per share on April 24, 2025, to close at $12.93 per share on April 25, 2025.

Then, on August 1, 2025, the Company reported disappointing second quarter 2025 financial results, including a year-over-year decrease in net sales, and further reduced the Company’s 2025 guidance—now projecting organic revenue growth of -2% to 0%. Defendants again attributed Avantor’s poor results and outlook to “increased competitive intensity,” and further admitted that the Company did not expect the competitive environment to materially improve in the remainder of 2025 and weak performance would therefore likely persist. In response to this news, the price of Avantor common stock declined $2.08 per share, or more than 15%, from a close of $13.44 per share on July 31, 2025, to close at $11.36 per share on August 1, 2025.

Finally, on October 29, 2025, the Company reported weak third quarter 2025 financial results, including -5% organic revenue growth (below the guidance Defendants had provided in August), and a net loss of $712 million, which Defendants primarily attributed to a non-cash goodwill impairment charge of $785 million. Defendants revealed that the impairment charge was necessary due in part to “competitive pressures” that had “meaningfully impacted” the Company’s margins, and further admitted that the Company had lost several large contracts. On this news, the price of Avantor common stock declined $3.50 per share, or more than 23%, from a close of $15.08 per share on October 28, 2025, to close at $11.58 per share on October 29, 2025.

The complaint alleges that, throughout the Class Period, Defendants made materially false and/or misleading statements, as well as failed to disclose material adverse facts, about the Company’s business and operations. Specifically, Defendants misrepresented and/or failed to disclose that: (1) Avantor’s competitive positioning was weaker than Defendants had publicly represented; (2) Avantor was experiencing negative effects from increased competition; and (3) as a result, Defendants’ representations about the Company’s business, operations, and prospects were materially false and misleading and/or lacked a reasonable basis.

THE LEAD PLAINTIFF PROCESS:

Avantor investors may, no later than December 29, 2025, seek to be appointed as a lead plaintiff representative of the class through Kessler Topaz Meltzer & Check, LLP or other counsel, or may choose to do nothing and remain an absent class member. A lead plaintiff is a representative party who acts on behalf of all class members in directing the litigation. The lead plaintiff is usually the investor or small group of investors who have the largest financial interest and who are also adequate and typical of the proposed class of investors. The lead plaintiff selects counsel to represent the lead plaintiff and the class and these attorneys, if approved by the court, are lead or class counsel. Your ability to share in any recovery is not affected by the decision of whether or not to serve as a lead plaintiff.

Kessler Topaz Meltzer & Check, LLP encourages Avantor investors who have suffered significant losses to contact the firm directly to acquire more information.

CLICK HERE TO SIGN UP FOR THE CASE OR GO TO: www.ktmc.com/new-cases/avantor-inc?utm_source=Businesswire&mktm=PR

ABOUT KESSLER TOPAZ MELTZER & CHECK, LLP:

Kessler Topaz Meltzer & Check, LLP prosecutes class actions in state and federal courts throughout the country and around the world. The firm has developed a global reputation for excellence and has recovered billions of dollars for victims of fraud and other corporate misconduct. All of our work is driven by a common goal: to protect investors, consumers, employees and others from fraud, abuse, misconduct and negligence by businesses and fiduciaries. The complaint in this action was filed by Kessler Topaz Meltzer & Check, LLP. For more information about Kessler Topaz Meltzer & Check, LLP please visit www.ktmc.com.

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