Exhibit 99.1

Jazz’s Proposed Acquisition of Chimerix to Further Diversify Oncology Portfolio Reinforces commitment to bringing medicines to patients with significant unmet needs Significant Anticipated Strategic and Financial Benefits Transaction Terms Strong strategic fit: Will strengthen Jazz’s presence in the rare oncology space ~$935 million total consideration Anticipated near-term launch: Expect US launch of dordaviprone, if approved, as early as second half of 2025, leveraging Jazz’s existing commercial capabilities $8.55 Durable revenue stream: Will create an additional per share in cash durable revenue opportunity for Jazz with patent protection expected into 2037, with potential to receive patent term extension Expected to close in the second quarter of 2025 Limited Options to Treat H3 K27M-Mutant Diffuse Glioma —Rare, high-grade brain tumor most commonly affects children and young adults “ Adding dordaviprone to our —Patient population with significant unmet need oncology R&D pipeline will further —No other FDA approved therapies specifically for patients with diversify our portfolio with a H3 K27M-mutant diffuse glioma medicine that addresses a significant unmet need with no other Dordaviprone Has Potential FDA-approved therapies and limited to Become a Standard of Care treatment options for this patient population. If approved, —Novel first-in-class small molecule treatment in development for dordaviprone has the potential to patients with H3 K27M-mutant diffuse glioma rapidly become a standard of care —Patient benefit observed across several clinical studies for a rare oncology disease and also —Consistently favorable safety profile observed in clinical studies contribute durable revenue both as monotherapy and in combination with other treatment beginning in the near-term.” approaches, including radiation BRUCE COZADD, Chairman and Chief —FDA accepted NDA1, granted Priority Review and assigned Executive Officer, Jazz Pharmaceuticals PDUFA2 action date of August 18, 2025—Ongoing Phase 3 ACTION trial has potential to confirm clinical benefit of dordaviprone in recurrent H3 K27M-mutant diffuse glioma and extend its use to front-line patients 1. New Drug Application 2. Prescription Drug User Fee Act For more information, visit www.jazzpharma.com or www.chimerix.com 

Caution Concerning Forward-Looking Jazz obtaining, maintaining and defending intellectual property protection and exclusivity for its products and product candidates; risks and uncertainties associated Statements with global economic, financial, and healthcare system disruptions and the current and potential future negative impacts to Jazz’s or Chimerix’s business operations and This communication contains forward-looking statements that involve risks and financial results; the sufficiency of Jazz’s cash flows and capital resources; risks and uncertainties relating to future events and the future performance of Jazz uncertainties associated with Jazz’s ability to achieve targeted or expected future Pharmaceuticals plc. (“Jazz”) and Chimerix, Inc. (“Chimerix”), including statements financial performance and results and the uncertainty of future tax, accounting and regarding Jazz’s proposed acquisition of Chimerix, the anticipated occurrence, other provisions and estimates; and other risks and uncertainties affecting Jazz and manner and timing of the proposed tender offer, the closing of the proposed Chimerix, including those described from time to time under the caption “Risk Factors” acquisition, the expected timing thereof and the anticipated benefits of the proposed and elsewhere in their respective filings and reports with the U.S. Securities and acquisition, including benefits from dordaviprone’s potential to become a standard of Exchange Commission (the “SEC”), including Jazz’s Annual Report on Form 10-K for care for a rare oncology disease and also contribute durable revenue beginning in the the fiscal year ended December 31, 2024 and Chimerix’s Quarterly Report on Form near-term; the potential for a U.S. commercial launch of dordaviprone if approved as 10-Q for the quarterly period ended September 30, 2024 and Annual Report on Form early as the second half of 2025; the potential of the ongoing Phase 3 ACTION trial to 10-K for the fiscal year ended December 31, 2023 as well as the Tender Offer confirm clinical benefit of dordaviprone in recurrent H3 K27M-mutant diffuse glioma Statement on Schedule TO and related tender offer documents to be filed by Jazz and and extend its use in first-line patients; expected patent protection for dordaviprone its acquisition subsidiary, Pinetree Acquisition Sub, Inc., and the Solicitation/ and the potential for patent term extension; and other statements that are not historical Recommendation Statement on Schedule 14D-9 to be filed by Chimerix. Any facts. Actual results could differ materially from those anticipated in these forward- forward-looking statements are made based on the current beliefs and judgments of looking statements. Except as required by law, Jazz assumes no obligation to update Jazz’s management, and the reader is cautioned not to rely on any forward-looking these forward-looking statements, whether as a result of new information, future statements made by Jazz. Except as required by law, Jazz does not undertake any events or otherwise. These statements, which represent Jazz’s current expectations obligation to update (publicly or otherwise) any forward-looking statement, including or beliefs concerning various future events that are subject to significant risks and without limitation any financial projection or guidance, whether as a result of new uncertainties, may contain words such as “may,” “will,” “would,” “could,” “expect,” information, future events, or otherwise. “anticipate,” “intend,” “plan,” “believe,” “estimate,” “project,” “seek,” “should,” “strategy,” Additional Information and Where to Find It “future,” “opportunity,” “potential” or other similar words and expressions indicating future results. Risks that may cause these forward-looking statements to be The tender offer referenced in this communication has not yet commenced. This inaccurate include, without limitation: uncertainties as to the timing of the tender offer communication is for informational purposes only and is neither an offer to purchase for the proposed acquisition; uncertainties as to how many of Chimerix’s stockholders nor a solicitation of an offer to sell any securities, nor is it a substitute for the tender will tender their stock in the tender offer; the possibility that competing offers or offer materials that Chimerix, Jazz or its acquisition subsidiary, Pinetree Acquisition acquisition proposals will be made; the possibility that various closing conditions for Sub, Inc., is expected to file with the SEC upon the commencement of the tender the proposed acquisition may not be satisfied or waived, including that a governmental offer. The solicitation and offer to tender and the offer to buy Chimerix stock will only entity may prohibit, delay, or refuse to grant approval for the consummation of the be made pursuant to a tender offer statement on Schedule TO, including an Offer to transaction (or only grant approval subject to adverse conditions or limitations); the Purchase and related tender offer materials that Jazz and its acquisition subsidiary, difficulty of predicting the timing or outcome of regulatory approvals or actions, if any; Pinetree Acquisition Sub, Inc. is expected to file with the SEC. At the time the tender the possibility that the transaction does not close; risks and uncertainties related to the offer is commenced, Jazz and its acquisition subsidiary will file a Tender Offer parties’ ability to realize the anticipated benefits of the proposed acquisition, including Statement on Schedule TO and thereafter Chimerix is expected to file a Solicitation/ the possibility that the expected benefits from the proposed acquisition will not be Recommendation Statement on Schedule 14D-9 with the SEC with respect to the realized or will not be realized within the expected time period and that Jazz and tender offer. CHIMERIX’S STOCKHOLDERS AND OTHER INVESTORS ARE Chimerix will not be integrated successfully or that such integration may be more URGED TO READ CAREFULLY THE TENDER OFFER MATERIALS (INCLUDING difficult, time-consuming or costly than expected; the risk that the effects of the AN OFFER TO PURCHASE, A RELATED LETTER OF TRANSMITTAL AND transaction on relationships with employees, customers, suppliers, other business CERTAIN OTHER TENDER OFFER DOCUMENTS), AS WELL AS THE partners or governmental entities; negative effects of the consummation of the SOLICITATION/RECOMMENDATION STATEMENT ON SCHEDULE 14D-9 proposed acquisition on the market price of Jazz’s ordinary shares or Chimerix’s BECAUSE THEY WILL EACH CONTAIN IMPORTANT INFORMATION THAT common stock and/or Jazz’s operating results; significant transaction costs; unknown HOLDERS OF CHIMERIX SECURITIES AND OTHER INVESTORS SHOULD or inestimable liabilities; the risk of litigation and/or regulatory actions related to the CONSIDER BEFORE MAKING ANY DECISION WITH RESPECT TO THE proposed acquisition; risks associated with Jazz’s ability to fund the acquisition with TENDER OFFER. The Offer to Purchase, the related Letter of Transmittal, certain existing cash and investments; risks and uncertainties associated with effectively other tender offer documents, as well as the Solicitation/Recommendation launching and commercializing products and product candidates such as Statement on Schedule 14D-9, will be made available to all stockholders of Chimerix dordaviprone, if approved; risks and uncertainties associated with the successful at no expense to them and will also be made available for free at the SEC’s website at completion of development and regulatory activities with respect to dordaviprone; www.sec.gov. Additional copies may be obtained for free by contacting either Jazz risks and uncertainties associated with obtaining and maintaining adequate coverage or Chimerix. Copies of the documents filed with the SEC by Chimerix will be and reimbursement for Jazz’s products; risks and uncertainties associated with the available free of charge on Chimerix’s website at https://www.chimerix.com or by time-consuming and uncertain regulatory approval process, including the risk that contacting Chimerix at IR@chimerix.com. Copies of the documents filed with the Chimerix’s NDA for dordaviprone seeking accelerated approval for treatment of H3 SEC by Jazz will be available free of charge on Jazz’s website at https://investor. K27M-mutant diffuse glioma in adult and pediatric patients with progressive disease jazzpharma.com or by contacting Jazz’s Investor Relations Department at following prior therapy may not be approved by FDA in a timely manner or at all; risks investorinfo@jazzpharma.com. and uncertainties associated with the costly and time-consuming pharmaceutical product development and the uncertainty of clinical success, including risks related to In addition to the Offer to Purchase, the related Letter of Transmittal and certain other failure or delays in successfully initiating or completing clinical trials and assessing tender offer documents, as well as the Solicitation/Recommendation Statement on patients, including with respect to current and planned future clinical trials of Schedule 14D-9, Jazz and Chimerix each file annual, quarterly and current reports, dordaviprone; risks and uncertainties associated with protecting and enhancing proxy statements and other information with the SEC, which are available to the public intellectual property rights and Jazz’s commercial success being dependent upon over the internet at the SEC’s website at http://www.sec.gov