Exhibit 99.1

Replimune Reports Fiscal Third Quarter 2026 Financial Results and Provides Corporate Update

April 10, 2026 Target Action Date for RP1 in Advanced Melanoma

Woburn, MA, February 3, 2026 – Replimune Group, Inc. (Nasdaq: REPL), a clinical stage biotechnology company pioneering the development of novel oncolytic immunotherapies, today announced financial results for the fiscal third quarter ended December 31, 2025 and provided a business update.

The Company's Biologics License Application (BLA) resubmission for RP1 (vusolimogene oderparepvec) in anti-PD-1 failed melanoma was accepted by the FDA in October 2025 with a Prescription Drug User Fee Act (PDUFA) target action date of April 10, 2026. Commercial readiness activities are well underway to support a potential launch, if approved.

The Company has amended its existing loan agreement with Hercules Capital, Inc. The amendment included the draw down of $35 million upon closing and the potential to draw another $120 million at post approval milestones. The amendment also delays the repayment of debt from 2026 to 2027. The Company has extended its cash runway late into the first quarter of 2027.

“We have been engaged with the FDA in the review of the BLA resubmission for RP1,” said Sushil Patel, Ph.D., CEO of Replimune. “Advanced melanoma patients can progress quickly and are in urgent need of safe and effective treatment options. Our team remains ready to launch RP1 with commercial supply produced and the commercial organization prepared to engage with our target accounts rapidly, assuming FDA approval.”

Program Highlights & Milestones

RP1 (vusolimogene oderparepvec)

RP2

Financial Highlights

About RP1

RP1 (vusolimogene oderparepvec) is Replimune’s lead product candidate and is based on a proprietary strain of herpes simplex virus engineered and genetically armed with a fusogenic protein (GALV-GP R-) and GM-CSF intended to maximize tumor killing potency, the immunogenicity of tumor cell death, and the activation of a systemic anti-tumor immune response.

About RP2

RP2 is based on a proprietary strain of herpes simplex virus engineered and genetically armed with a fusogenic protein (GALV-GP R-) and GM-CSF intended to maximize tumor killing potency, the immunogenicity of tumor cell death and the activation of a systemic anti-tumor immune response. RP2 additionally expresses an anti-CTLA-4 antibody-like molecule, as well as GALV-GP R- and GM-CSF. RP2 is intended to provide targeted and potent delivery of these proteins to the sites of immune response initiation in the tumor and draining lymph nodes, with the goal of focusing systemic-immune-based efficacy on tumors and limiting off-target toxicity.

About Replimune

Replimune Group, Inc., headquartered in Woburn, MA, was founded in 2015 with the mission to transform cancer treatment by pioneering the development of novel oncolytic immunotherapies. Replimune’s proprietary RPx platform is based on a potent HSV-1 backbone intended to maximize immunogenic cell death and the induction of a systemic anti-tumor immune response. The RPx platform is intended to ignite local activity consisting of direct selective virus-mediated killing of the tumor resulting in the release of tumor derived antigens and altering of the tumor microenvironment to then activate a strong and durable systemic response. The RPx product candidates are expected to be synergistic with most established and experimental cancer treatment modalities, leading to the versatility to be developed alone or combined with a variety of other treatment options. For more information, please visit www.replimune.com.

Forward Looking Statements

This press release contains forward looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, including statements regarding our expectations about our cash runway, the status of the FDA review of our BLA for RP1 or potential approval of such BLA, the design and advancement of our clinical trials, the timing and sufficiency of our clinical trial outcomes to support potential approval of any of our product candidates, the regulatory review process and timing of potential product approval, our goals to develop and commercialize our product candidates, patient enrollments in our existing and planned clinical trials and the timing thereof, and other statements identified by words such as “could,” “expects,” “intends,” “may,” “plans,” “potential,” “should,” “will,” “would,” or similar expressions and the negatives of those terms. Forward-looking statements are not promises or guarantees of future performance, and are subject to a variety of risks and uncertainties, many of which are beyond our control, and which could cause actual results to differ materially from those contemplated in such forward-looking statements. These factors include risks related to the outcome of FDA’s review process, our limited operating history, our ability to generate positive clinical trial results for our product candidates, the costs and timing of operating our in-house manufacturing facility, the timing and scope of regulatory approvals, the availability of combination therapies needed to conduct our clinical trials, changes in laws and regulations to which we are subject, competitive pressures, our ability to identify additional product candidates, political and global macro factors including the impact of a global pandemic and related public health issues and the ongoing political and military conflicts, including trade conflicts, and other risks as may be detailed from time to time in our Annual Reports on Form 10-K and Quarterly Reports on Form 10-Q and other reports we file with the Securities and Exchange Commission. Our actual results could differ materially from the results described in or implied by such forward-looking statements. Forward-looking statements speak only as of the date hereof, and, except as required by law, we undertake no obligation to update or revise these forward-looking statements.

Investor Inquiries

Chris Brinzey

ICR Healthcare

339.970.2843

chris.brinzey@icrhealthcare.com

Media Inquiries

Arleen Goldenberg

Replimune

917.548.1582

media@replimune.com

Replimune Group, Inc.

Condensed Consolidated Statements of Operations

(Amounts in thousands, except share and per share amounts)

(Unaudited)

Replimune Group, Inc.

Condensed Consolidated Balance Sheets

(Amounts In thousands, except share and per share amounts)

(Unaudited)