Replimune Presents Final First-in-Human Data for RP2 in Advanced Solid Tumors During Oral Presentation at the 2026 American Society of Clinical Oncology Annual Meeting
Rhea-AI Summary
Replimune (NASDAQ: REPL) reported final first-in-human Phase 1 data for RP2, alone and with nivolumab, in 85 heavily pretreated patients with advanced solid tumors at the 2026 ASCO meeting.
RP2 showed objective responses, durable disease control, systemic immune activity, and a favorable safety profile, supporting an ongoing randomized Phase 2/3 uveal melanoma trial.
AI-generated analysis. Not financial advice.
Positive
- RP2 monotherapy objective response rate of 19.0% (4/21 evaluable patients)
- RP2+nivolumab objective response rate of 19.1% and disease control rate of 48.9%
- Pooled uveal melanoma objective response rate of 33.3% across RP2 regimens
- Responses durable with monotherapy median duration of response not reached (range 11.5–27.3+ months)
- Combination median duration of response 22.1 months (range 2.8–35.2+ months)
- No Grade 4/5 treatment-related adverse events and no unexpected toxicities reported
Negative
- None.
News Market Reaction – REPL
On the day this news was published, REPL gained 3.57%, reflecting a moderate positive market reaction. This price movement added approximately $25M to the company's valuation, bringing the market cap to $717.56M at that time.
Data tracked by StockTitan Argus on the day of publication.
Key Figures
Market Reality Check
Peers on Argus
REPL rose 85.68% while key biotech peers showed modest, mixed moves (e.g., BCYC +0.53, CRVS -1.19, NBTX -0.83), indicating a stock-specific reaction rather than a sector-wide shift.
Historical Context
| Date | Event | Sentiment | Move | Catalyst |
|---|---|---|---|---|
| May 29 | RP1 BLA resubmission | Positive | +85.7% | FDA discussions cleared path to resubmit RP1 BLA for advanced melanoma. |
| Apr 27 | ASCO presentations | Positive | +10.7% | Planned multiple ASCO presentations for RP1/RP2 clinical updates. |
| Apr 10 | RP1 FDA CRL | Negative | -64.3% | FDA Complete Response Letter for RP1 BLA in advanced melanoma. |
| Mar 2 | Investor conferences | Neutral | -6.4% | Management scheduled presentations at two March 2026 investor conferences. |
| Feb 3 | Q3 earnings update | Neutral | +5.8% | Reported Q3 2026 results, cash runway into late Q1 2027, and trial progress. |
Recent news reactions have generally aligned with sentiment, with sharp moves on major regulatory updates and more mixed responses to routine events.
Over the last few months, REPL has experienced major regulatory and clinical milestones. A Apr 10 FDA CRL for RP1 plus nivolumab in advanced melanoma led to a -64.29% move, followed by a planned BLA resubmission on May 29 that coincided with a +85.68% reaction. ASCO presentation news on Apr 27 saw a +10.74% move. Earnings on Feb 3 and conference appearances on Mar 2 drove smaller, mixed reactions, showing the stock’s largest moves tend to cluster around pivotal regulatory and clinical announcements.
Regulatory & Risk Context
An effective shelf registration statement on Form S-3/A dated Nov 6, 2025 covers up to $250,000,000 of securities, including an at-the-market program of up to $100,000,000 of common stock within that amount. The shelf shows 0 reported usage so far, with expiration on Nov 6, 2028. This framework allows the company to raise capital from time to time as needed.
Market Pulse Summary
This announcement highlights final first-in-human data for RP2 in advanced solid tumors, with ORRs of 19.0% as monotherapy and 19.1% in combination, plus a pooled uveal melanoma ORR of 33.3% and durable responses. It follows a period marked by an FDA CRL and a planned RP1 BLA resubmission. Investors may track progression of the randomized Phase 2/3 uveal melanoma trial, future regulatory interactions, and any capital raised under the existing $250,000,000 shelf.
Key Terms
oncolytic immunotherapies medical
nivolumab medical
objective response rate (ORR) medical
disease control rate medical
phase 1 first-in-human (FIH) medical
biomarker medical
immunologically "cold" medical
AI-generated analysis. Not financial advice.
WOBURN, Mass., May 31, 2026 (GLOBE NEWSWIRE) -- Replimune Group, Inc. (NASDAQ: REPL), a clinical-stage biotechnology company pioneering the development of novel oncolytic immunotherapies, today presented final first-in-human data for RP2 alone and in combination with nivolumab in patients with advanced solid tumors during an oral session at the 2026 American Society of Clinical Oncology annual meeting.
Key findings are detailed below.
Oral Presentation: RP2 oncolytic immunotherapy alone and in combination with nivolumab (nivo) in patients with advanced solid tumors: Final safety, efficacy, and biomarker results from the phase 1 first-in-human (FIH) study; Date/Time: May 31, 2026, 9:12 AM CDT; Location: Arie Crown Theater; Abstract: 2504; Presenter: Joseph Sacco, PhD, MBChB
- The Phase 1 first-in-human trial enrolled 85 heavily pretreated patients with advanced solid tumors, including uveal melanoma, colorectal cancer, head and neck cancers, pancreatic cancer, cutaneous melanoma, and sarcoma.
- Patients had received a median of 2 prior lines of systemic therapy;
42% had received prior immune checkpoint inhibitor (ICI) therapy - RP2 monotherapy achieved an objective response rate (ORR) of
19.0% (4/21 evaluable patients), with responses observed in uveal melanoma, esophagogastric adenocarcinoma, chordoma, and mucoepidermoid carcinoma - RP2 in combination with nivolumab achieved an ORR of
19.1% (9/47 evaluable patients), with a disease control rate of48.9% - In uveal melanoma, where a randomized Phase 2/3 trial is enrolling, the pooled ORR (RP2 in combination with nivolumab and RP2 monotherapy) was
33.3% - Responses were durable: median duration of response was not reached in the monotherapy group (range: 11.5–27.3+ months) and was 22.1 months in the combination group (range: 2.8–35.2+ months)
- Tumor regression was observed in both injected and non-injected lesions, including in all 3 monotherapy responders who had non-injected lesions, demonstrating a systemic immune response beyond the site of injection
- Translational analyses demonstrated that RP2 reprogrammed tumors from immunologically "cold" to immune-inflamed, upregulated T-cell cytotoxicity and antigen presentation pathways, and significantly expanded HSV-1-specific and tumor-associated (MAGE) TCR clones, confirming the intended mechanism of action and systemic immune engagement.
- RP2 monotherapy and RP2 in combination with nivolumab were well tolerated with no unexpected toxicities, no Grade 4 or 5 treatment-related adverse events, and no increase in immune-related adverse events beyond the expected profile of nivolumab alone; the most common events were low-grade pyrexia, chills, and fatigue, consistent with systemic immune activation
- Based on these results, RP2 is being evaluated in combination with nivolumab in patients with metastatic uveal melanoma in a randomized Phase 2/3 trial (NCT06581406)
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 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
