Curium Announces Definitive Agreement to Merge with Lantheus

• Strategic transaction would bring Curium’s theranostics portfolio and global manufacturing platform together with Lantheus’ complementary U.S. radiodiagnostics business

• Total transaction consideration to Lantheus shareholders of up to $114.50 per share in cash for an aggregate transaction value of up to $8.0 billion – representing a premium of 38% to Lantheus’ unaffected 60-day volume-weighted average price and a premium of 29% to Lantheus’ unaffected 30-day volume-weighted average price

• Provides for near-term certain value for Lantheus shareholders of $102.50 per share in cash at closing and up to an additional $12.00 per share of Contingent Value Rights tied to specified performance milestones for Lantheus’ commercial portfolio

• Combined company would serve oncology, neurology and cardiology patients across more than 70 countries

BOSTON, MA and BEDFORD, MA August 3, 2026 – Curium™, a leading, global radiopharmaceutical company with proven expertise in the development, manufacturing and supply of radiopharmaceuticals that improve the way cancer is diagnosed and treated, and Lantheus Holdings, Inc. (“Lantheus” or “Company”) (NASDAQ: LNTH), today announced that Curium US Holdings LLC (“Curium US”) and Lantheus have entered into a definitive agreement under which Lantheus, a leading radiopharmaceutical-focused company committed to enabling clinicians to Find, Fight and Follow disease to deliver better patient outcomes, will merge with a wholly-owned subsidiary of Curium US.

Under the terms of the definitive agreement, Curium US will acquire all of the outstanding shares of Lantheus for $102.50 per share in cash at closing, plus non-transferable Contingent Value Rights (“CVRs”) providing for up to $12.00 per share in potential additional cash payments, subject to achievement of specified commercial milestones for Lantheus’ products through 2030. The transaction represents a total per share consideration of up to $114.50 and a total transaction value of up to approximately $8.0 billion. Together, Curium and Lantheus are positioned to create a radiopharmaceutical company spanning diagnostics and therapeutics, with the infrastructure and capabilities to serve patients in more than 70 countries. The Board of Directors of Lantheus has unanimously approved the transaction.

The cash consideration provides for near-term certain value to Lantheus shareholders at closing and the CVR structure provides meaningful potential additional upside participation in the commercial performance of Lantheus’ main product lines. The total transaction value represents a premium of 38% to Lantheus’ unaffected 60-day volume-weighted average price (“VWAP”), a premium of 29% to Lantheus’ unaffected 30-day VWAP, and a premium of 21% to Lantheus’ unaffected closing price, in each case as of May 21, 2026, the last trading day prior to the first media report of a potential sale transaction.

“Lantheus is the ideal partner to accelerate what we have been building at Curium,” said Renaud Dehareng, Chief Executive Officer of Curium Group. “We have executed a strategy to build an innovative, theranostics platform by expanding our global manufacturing footprint, advancing our radioligand therapy pipeline across key regions, and positioning Curium to drive the next generation of theranostics innovation. Lantheus’ complementary business accelerates our strategy with a robust U.S. commercial infrastructure, a complementary F18-isotope based prostate diagnostics franchise and marks our entry in the U.S. market for diagnostic solutions targeting Neurology and Echocardiography. Together, we will provide meaningful theranostic options to patients from SPECT and PET diagnostics to targeted radioligand therapy across the globe. This combination unlocks an opportunity that neither company could achieve alone, as it positions us to reach significantly more patients and clinicians globally.”

“We believe this transaction is the ultimate validation of what the Lantheus team has built over seven decades of innovation in radiopharmaceuticals,” said Mary Anne Heino, Executive Chair and Chief Executive Officer of Lantheus. “Combining strategically with Curium brings together two pioneers with complementary strengths and a shared passion for nuclear medicine. Together, we can broaden and accelerate patient access to life-changing diagnostics and therapeutics and fully realize the differentiated outcomes and value radiopharmaceuticals can deliver. I am tremendously proud of everything our people have achieved, and I am confident this combination is the best path forward for our shareholders, our employees, and the millions of patients we serve.”

Curium was established in 2017 by global investment firm CapVest Partners LLP (“CapVest”) which remains its controlling shareholder and last year completed the successful recapitalization of Curium in a transaction which valued the Curium Group at approximately $7 billion. Kate Briant, Senior Partner at CapVest and Chair of Curium’s Board of Directors, said: “This transaction underlies our ongoing commitment to Curium’s growth and emphasizes our strong conviction in the potential of nuclear medicine and the future of the sector. This highly strategic combination will allow the combined company to capitalize on the significant emerging opportunities and, most importantly, will allow us to accelerate bringing life-changing solutions to healthcare professionals and benefit millions of patients (and their families) around the world.”

Curium has a proven record of developing, manufacturing, and supplying diagnostic and therapeutic radiopharmaceuticals globally with a deep manufacturing expertise, and a robust theranostics pipeline. Lantheus has pioneered the radiodiagnostics landscape in the U.S. for 70 years and has demonstrated success building and growing a commercial diagnostic business, including PYLARIFY that helped establish PSMA PET as the standard of care in prostate cancer imaging, maintaining DEFINITY’s position as a category leader in cardiac ultrasound enhancing agents for 25 years, and driving Neuraceq to become the fastest-growing beta-amyloid PET agent on the market. The combined entity will span the full nuclear medicine value chain: from isotope production and manufacturing to diagnostic imaging and targeted radionuclide therapy, delivering nuclear medicine solutions to patients and healthcare systems across more than 70 countries.

The Lantheus Board of Directors, with the assistance of its financial advisors, conducted a comprehensive evaluation of its strategic options, including outreach to multiple third parties and remaining as a standalone company. After concluding this robust process, the Board unanimously determined that this transaction is in the best interests of Lantheus and its shareholders as the value maximizing path relative to the other strategic options.

Transaction Details

Under the terms of the agreement, Curium US will acquire all of the outstanding shares of Lantheus common stock for $102.50 per share in cash at closing. In addition, Lantheus shareholders will receive up to $12.00 per share in non-transferable CVRs, entitling holders to the following additional cash payments upon achievement of applicable milestones:

There can be no assurance that any payments will be made with respect to the CVRs. If all milestones are achieved, per share consideration under the CVRs would be $12.00 per share.

The transaction is expected to be financed through a combination of debt and equity and is not subject to any financial conditions or other related contingencies.

Until the transaction closes, Lantheus will continue to operate as an independent, publicly traded company. Upon completion, Lantheus will cease to be a publicly traded company.

The transaction is currently expected to close in the first half of 2027, subject to satisfaction of customary closing conditions, including receipt of Lantheus shareholder approval and required regulatory approvals.

Lantheus Second Quarter Financial Results

Lantheus is expected to announce its financial results and provide a business update for the second quarter of 2026 prior to market open on August 6, 2026. Due to the pending transaction with Curium, Lantheus will not be hosting a conference call and will be suspending its previously issued FY 2026 guidance.

Advisors

Morgan Stanley & Co. LLC acted as lead financial advisor to Lantheus, and BofA Securities, Inc. and Solomon Partners Securities LLC also acted as financial advisors to Lantheus. Covington & Burling LLP and Ropes & Gray LLP acted as legal counsel to Lantheus.

Jefferies LLC acted as lead financial advisor to Curium. J.P. Morgan Securities LLC and PJT Partners LP also acted as financial advisors to Curium.  Kirkland & Ellis LLP and Arnold & Porter Kaye Scholer LLP acted as legal counsel to Curium.

^[1]Refers to “Aggregate Adjusted Sales” which consists of, for a given period, the sum of (a) the total gross amounts accrued or recognized during such period by or on behalf of any selling entity (as defined in the form of CVR Agreement) in respect of sales of product (including any associated freight, services and other revenue), and net only of discounts, credits, rebates and allowances (which, for the avoidance of doubt, do not include any reductions for any internal or external sales commissions) (other than clinical collaboration revenue), (b) royalties accrued or recognized by or on behalf of any selling entity, (c) sublicense income accrued or recognized by or on behalf of any selling entity, (d) clinical collaboration revenue accrued or recognized by or on behalf of any selling entity and (e) DEFINITY kit revenue (as defined in the CVR agreement) accrued or recognized by or on behalf of any selling entity, in each case of (a) through (e), net of sales tax, VAT, pharmaceutical or similar taxes, in each case, as more fully set forth in the form of CVR Agreement.

^[2]“Global Prostate Cancer Diagnostics” consists of PYLARIFY, PYLARIFY TruVu,and LNTH-2401; any radiodiagnostic containing piflufolastat or RM2; and any future PSMA-targeted radiodiagnostic derived from any of the foregoing.

^[3]“Global Neurology Diagnostics” consists of Neuraceq, MK-6240, NAV-4694, LNTH-2620; any radiodiagnostic containing florbetaben, florquinitau, flutafuranol, or PI-2620; and any future radiodiagnostic derived from any of the foregoing.

^[4]”Global DEFINITY Business” consists of DEFINITY and microbubble technology products containing perflutren; and any future microbubble technology products derived from any of the foregoing.