Immunocore presents KIMMTRAK clinical data demonstrating that patients with stable disease and confirmed tumor reduction have similar clinical outcomes to patients with partial response

Immunocore presents KIMMTRAK clinical data demonstrating that patients with stable disease and confirmed tumor reduction have similar clinical outcomes to patients with partial response Data were presented at ASCO 2024, where Immunocore also presented Phase 1 data from its PRAME trial with brenetafusp (IMC-F106C) in advanced cutaneous melanoma (OXFORDSHIRE, England & CONSHOHOCKEN, PA & ROCKVILLE, MD, US, June 1, 2024) Immunocore Holdings plc (Nasdaq: IMCR) (“Immunocore” or the “Company”), a commercial-stage biotechnology company pioneering and delivering transformative immunomodulating medicines to radically improve outcomes for patients with cancer, infectious diseases and autoimmune diseases, today presented three posters about KIMMTRAK® (tebentafusp-tebn) for the treatment of patients with unresectable or metastatic uveal melanoma (mUM) at the 2024 ASCO (American Society for Clinical Oncology) Annual Meeting. These data showed that treatment benefit for patients with stable disease and any confirmed tumor reduction was similar to patients with partial response. “In both Phase 2 and Phase 3 KIMMTRAK trials, patients with stable disease and durable tumor reduction, regardless of depth, had similar benefit as patients with RECIST partial response,” said Mohammed Dar, Senior Vice President, Clinical Development, and Chief Medical Officer, Immunocore. “The data presented at ASCO builds upon the mounting evidence confirming that disease control is the best early radiographic measure of clinical benefit across our ImmTAC platform.” “KIMMTRAK is now the standard of care, in launched countries, for HLA-A*02:01-positive patients with metastatic or unresectable uveal melanoma,” said Ralph Torbay, Immunocore’s Chief Commercial Officer. “Physicians can now leverage these data, presented at ASCO today, to positively inform their conversations with patients who have stable disease and minor reductions in tumor size.” Of the 127 patients treated with KIMMTRAK in the Phase 2 trial (IMCgp100-102), 25% (32/127) had any tumor reduction that was confirmed in at least one subsequent scan, including 6 partial responses (PR), an overall response rate of 5%, and 20% (26/127) stable disease (SD). The clinical outcomes in the 26 patients with SD were similar to the 6 PR patients, including durable duration of tumor reduction or response, ctDNA molecular response, and overall survival. In the Phase 3 trial (IMCgp100-202), KIMMTRAK-treated patients with SD who had any confirmed tumor reduction had durability of tumor reduction of 11 months, which was the same as the durability of response for patients with RECIST PR or CR. Full poster details: Stable disease with confirmed tumor reduction has a similar clinical outcome as RECIST partial response for tebentafusp in metastatic uveal melanomaPresenting author: Alexandra Ikeguchi Association between clinical and disease characteristics and detectable or undetectable baseline ctDNA in patients with metastatic uveal melanomaPresenting author: Paul Nathan Baseline and serial ctDNA dynamics predicts outcomes in patients treated with first-line tebentafusp including those who were and were not treated beyond progressionPresenting author: Ryan Sullivan ### About Immunocore Immunocore is a commercial-stage biotechnology company pioneering the development of a novel class of TCR bispecific immunotherapies called ImmTAX – Immune mobilizing monoclonal TCRs Against X disease – designed to treat a broad range of diseases, including cancer, autoimmune, and infectious disease. Leveraging its proprietary, flexible, off-the-shelf ImmTAX platform, Immunocore is developing a deep pipeline in multiple therapeutic areas, including nine active clinical and pre-clinical programs​ in oncology, infectious diseases, and autoimmune diseases. The Company’s most advanced oncology TCR therapeutic, KIMMTRAK has been approved for the treatment of HLA-A*02:01-positive adult patients with unresectable or metastatic uveal melanoma in the United States, European Union, Canada, Australia, and the United Kingdom. About KIMMTRAK® KIMMTRAK is a novel bispecific protein comprised of a soluble T cell receptor fused to an anti-CD3 immune-effector function. KIMMTRAK specifically targets gp100, a lineage antigen expressed in melanocytes and melanoma. This is the first molecule developed using Immunocore’s ImmTAC technology platform designed to redirect and activate T cells to recognize and kill tumor cells. KIMMTRAK has been approved for the treatment of HLA-A*02:01-positive adult patients with unresectable or metastatic uveal melanoma in the United States, European Union, Canada, Australia, and the United Kingdom. About Phase 2 IMCgp100-102 Trial IMCgp100-102 (NCT02570308) was an open-label, multi-center, single-arm trial of the safety and efficacy of tebentafusp in patients with previously treated mUM. The trial included 127 HLA-A*02:01+ 2L+ mUM patients, treated with tebentafusp at the recommended Phase 2 dose of 68mcg following intra-patient dose escalation of 20 mcg (week 1) and 30 mcg (week 2). The primary endpoint was objective response rate by blinded independent central review, with secondary objectives being overall survival (OS) and safety in 127 patients who had enrolled after progressing on one or more prior therapies. About Phase 3 IMCgp100-202 Trial IMCgp100-202 (NCT03070392) is a randomized pivotal trial that evaluated overall survival (OS) of KIMMTRAK compared to investigator’s choice (either pembrolizumab, ipilimumab, or dacarbazine) in HLA-A*02:01-positive adult patients with previously untreated mUM. KIMMTRAK demonstrated an unprecedented OS benefit with a Hazard Ratio (HR) in the intent-to-treat population favoring KIMMTRAK, HR=0.51 (95% CI: 0.37, 0.71); p< 0.0001, over investigator’s choice (82% pembrolizumab; 13% ipilimumab; 6% dacarbazine). IMPORTANT SAFETY INFORMATION Cytokine Release Syndrome (CRS), which may be serious or life-threatening, occurred in patients receiving KIMMTRAK. Monitor for at least 16 hours following first three infusions and then as clinically indicated. Manifestations of CRS may include fever, hypotension, hypoxia, chills, nausea, vomiting, rash, elevated transaminases, fatigue, and headache. CRS occurred in 89% of patients who received KIMMTRAK with 0.8% being grade 3 or 4. Ensure immediate access to medications and resuscitative equipment to manage CRS. Ensure patients are euvolemic prior to initiating the infusions. Closely monitor patients for signs or symptoms of CRS following infusions of KIMMTRAK. Monitor fluid status, vital signs, and oxygenation level and provide appropriate therapy. Withhold or discontinue KIMMTRAK depending on persistence and severity of CRS. Skin Reactions Skin reactions, including rash, pruritus, and cutaneous edema occurred in 91% of patients treated with KIMMTRAK. Monitor patients for skin reactions. If skin reactions occur, treat with antihistamine and topical or systemic steroids based on persistence and severity of symptoms. Withhold or permanently discontinue KIMMTRAK depending on the severity of skin reactions. Elevated Liver Enzymes Elevations in liver enzymes occurred in 65% of patients treated with KIMMTRAK. Monitor alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total blood bilirubin prior to the start of and during treatment with KIMMTRAK. Withhold KIMMTRAK according to severity. Embryo-Fetal Toxicity KIMMTRAK may cause fetal harm. Advise pregnant patients of potential risk to the fetus and patients of reproductive potential to use effective contraception during treatment with KIMMTRAK and 1 week after the last dose. The most common adverse reactions (≥30%) in patients who received KIMMTRAK were cytokine release syndrome, rash, pyrexia, pruritus, fatigue, nausea, chills, abdominal pain, edema, hypotension, dry skin, headache, and vomiting. The most common (≥50%) laboratory abnormalities were decreased lymphocyte count, increased creatinine, increased glucose, increased AST, increased ALT, decreased hemoglobin, and decreased phosphate. For more information, please see full Summary of Product Characteristics (SmPC) or full U.S. Prescribing Information (including BOXED WARNING for CRS). Forward Looking Statements This press release contains “forward-looking statements” within the meaning of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Words such as “may,” “will,” “believe,” “expect,” “plan,” “anticipate,” “estimate,” and similar expressions (as well as other words or expressions referencing future events or circumstances) are intended to identify forward-looking statements. All statements, other than statements of historical facts, included in this press release are forward-looking statements. These statements include, but are not limited to, statements regarding the expected clinical benefits of KIMMTRAK, including for mUM patients with stable disease and any confirmed tumor reduction, brenetafusp and Immunocore’s other product candidates, including RECIST response rate, tumor reduction, including the durability of tumor reduction, ctDNA molecular response, progression free survival and extended overall survival benefit; the expectation that different baseline characteristics and responses to therapy are prognostic factors for benefit from treatment with KIMMTRAK; the benefit of Immunocore’s clinical data for physicians treating patients with mUM; the value proposition of Immunocore’s products and product candidates, including KIMMTRAK and brenetafusp; and future development plans of Immunocore’s products and product candidates, including KIMMTRAK and brenetafusp. Any forward-looking statements are based on management’s current expectations and beliefs of future events and are subject to a number of risks and uncertainties that could cause actual events or results to differ materially and adversely from those set forth in or implied by such forward-looking statements, many of which are beyond Immunocore’s control. These risks and uncertainties include, but are not limited to, the impact of worsening macroeconomic conditions on Immunocore’s business, financial position, strategy and anticipated milestones, including Immunocore’s ability to conduct ongoing and planned clinical trials; Immunocore’s ability to obtain a clinical supply of current or future product candidates or commercial supply of KIMMTRAK or any future approved products, including as a result of health epidemics or pandemics, war in Ukraine, the conflict between Hamas and Israel, the broader risk of a regional conflict in the Middle East, or global geopolitical tension; Immunocore’s ability to obtain and maintain regulatory approval of its product candidates, including KIMMTRAK; Immunocore’s ability and plans in continuing to establish and expand a commercial infrastructure and to successfully launch, market and sell KIMMTRAK and any future approved products; Immunocore’s ability to successfully expand the approved indications for KIMMTRAK or obtain marketing approval for KIMMTRAK in additional geographies in the future; the delay of any current or planned clinical trials, whether due to patient enrollment delays or otherwise; Immunocore’s ability to successfully demonstrate the safety and efficacy of its product candidates and gain approval of its product candidates on a timely basis, if at all; competition with respect to market opportunities; unexpected safety or efficacy data observed during preclinical studies or clinical trials; actions of regulatory agencies, which may affect the initiation, timing and progress of clinical trials or future regulatory approval; Immunocore’s need for and ability to obtain additional funding, on favorable terms or at all, including as a result of worsening macroeconomic conditions, including inflation, interest rates and unfavorable general market conditions, and the impacts thereon of the war in Ukraine, the conflict between Hamas and Israel, and global geopolitical tension; Immunocore’s ability to obtain, maintain and enforce intellectual property protection for KIMMTRAK or any of its product candidates it or its collaborators are developing; and the success of Immunocore’s current and future collaborations, partnerships or licensing arrangements. These and other risks and uncertainties are described in greater detail in the section titled “Risk Factors” in Immunocore’s filings with the Securities and Exchange Commission, including Immunocore’s most recent Annual Report on Form 10-K for the year ended December 31, 2023 filed with the Securities and Exchange Commission on February 28, 2024, as well as discussions of potential risks, uncertainties, and other important factors in the Company’s subsequent filings with the Securities and Exchange Commission. All information in this press release is as of the date of the release, and the Company undertakes no duty to update this information, except as required by law. Contact Information Immunocore Sébastien Desprez, Head of CommunicationsT: +44 (0) 7458030732E: [email protected] on Twitter: @Immunocore Investor Relations Clayton Robertson, Head of Investor RelationsT: +1 (215) 384-4781E: [email protected]