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Issued: London, UK

• BLENREP is the first anti-BCMA (B-cell maturation antigen) therapy approved in the European Union
• Marketing authorisation follows the recent US approval of BLENREP

GlaxoSmithKline plc today announced the European Commission has granted conditional marketing authorisation for BLENREP (belantamab mafodotin) as monotherapy for the treatment of multiple myeloma in adult patients who have received at least four prior therapies and whose disease is refractory to at least one proteasome inhibitor, one immunomodulatory agent, and an anti-CD38 monoclonal antibody, and who have demonstrated disease progression on the last therapy. BLENREP is a first-in-class humanised anti-BCMA (B-cell maturation antigen) treatment for these?patients whose disease has progressed despite the current standard of care. Dr Hal Barron, Chief Scientific Officer and President R&D, GSK, said: ?The approval of BLENREP marks an important step forward for patients in Europe where nearly 50,000 new cases of multiple myeloma are diagnosed each year. Unfortunately, most of these patients will relapse or stop responding to current therapies so I am pleased that today?s news will give patients with limited treatment options access to the first approved anti-BCMA therapy.? The approval is?based on data from the pivotal DREAMM-2?(DRiving?Excellence in Approaches to Multiple Myeloma)?study, including 13-month follow-up data. These data demonstrated that treatment with single-agent BLENREP, administered as a 2.5 mg/kg dose every three weeks (Q3W), resulted in an overall response rate of 32%. The median duration of response was 11 months and median overall survival was 13.7 months. The safety and tolerability profile were consistent with previously reported data on BLENREP. The most commonly reported adverse events in the 2.5 mg/kg arm (greater than or equal to 20%) were keratopathy/microcyst-like epithelial changes or MECs (71%), thrombocytopenia (38%), anaemia (27%), blurred vision events (25%), nausea (25%), pyrexia (23%), increased aspartate aminotransferase (AST) (21%), infusion-related reactions (21%), and lymphopenia (20%). Dr Katja Weisel, Deputy Director and Associate Professor of Haematology/Oncology in the Department of Oncology, Haematology and Bone Marrow Transplantation with Department of Pneumonology, University Medical Centre Hamburg-Eppendorf in Germany and an investigator for the DREAMM-2 trial, said: ?Despite advances in treatment, multiple myeloma remains incurable and patients continue to cycle through therapies, with their prognosis worsening with each relapse. The approval of BLENREP, with its novel mechanism of action, represents a new class of treatment that patients can turn to when their cancer stops responding to other standard of care options.? BLENREP employs a multi-faceted mechanism of action and is directed toward BCMA, a cell-surface protein that plays an important role in the survival of plasma cells and is expressed on multiple myeloma cells.^[1] Dr Brian G.M. Durie, Chairman of the Board of the International Myeloma Foundation, said: ?The EC approval of BLENREP is good news for patients with refractory multiple myeloma whose cancer continues to progress and are in dire need of new treatment options. We appreciate GSK?s efforts to bring this new therapy to patients in the EU and for the commitment to addressing the needs of the multiple myeloma community.? BLENREP was granted PRIME designation in 2017 and the Conditional Marketing Authorisation Application was reviewed under European Medicines Agency?s accelerated assessment procedure, which is given if the EMA?s Committee for Medicinal Products for Human Use determines the treatment is of major interest from a public health perspective and represents a therapeutic innovation. Earlier this month, the US Food and Drug Administration approved BLENREP as a monotherapy treatment for adult patients with relapsed or refractory multiple myeloma who have received at least four prior therapies including an anti-CD38 monoclonal antibody, a proteasome inhibitor and an immunomodulatory agent, following a priority review for the company?s Biologics License Application.

About DREAMM-2

DREAMM-2 is an open label study of BLENREP. Patients in the trial had actively progressing multiple myeloma that had worsened despite current standard of care and were randomised to two arms to receive either 2.5 mg/kg or 3.4 mg/kg BLENREP Q3W. Overall, patients in DREAMM-2 had more advanced disease, poorer prognosis and performance status and also had a greater number of prior lines of therapy in comparison with patients in DREAMM-1, the first time in human study of BLENREP.

About multiple myeloma

There are approximately 48,000 new cases of multiple myeloma diagnosed each year across Europe.^[2]?Research into new treatments is needed as most patients will relapse or become refractory to available therapies.^[3]

About B-cell maturation antigen (BCMA)

The normal function of BCMA is to promote plasma cell survival by transduction of signals from two known ligands, BAFF (B-cell activating factor) and APRIL (a proliferation-inducing ligand). This pathway has been shown to be important for myeloma cell growth and survival. BCMA expression is limited to B cells at later stages of development. BCMA is expressed at varying levels in myeloma patients and BCMA membrane expression is universally detected in myeloma cell lines.^[4]

About BLENREP

BLENREP is an antibody drug conjugate comprising a humanised anti-B cell maturation antigen (BCMA) monoclonal antibody conjugated to the cytotoxic agent auristatin F via non-cleavable linker. The drug linker technology is licensed from Seattle Genetics; monoclonal antibody is produced using POTELLIGENT Technology licensed from BioWa.

Important information for BLENREP in the EU

Indication BLENREP is indicated as monotherapy for the treatment of multiple myeloma in adult patients, who have received at least four prior therapies and whose disease is refractory to at least one proteasome inhibitor, one immunomodulatory agent, and an anti-CD38 monoclonal antibody, and who have demonstrated disease progression on the last therapy.

Important safety information

Contraindications: Hypersensitivity to the active substance or to any of the excipients Warnings and precautions: Corneal adverse reactions have been reported with BLENREP (keratopathy or microcyst-like epithelial changes in corneal epithelium with or without changes in visual acuity, blurred vision, and dry eye symptoms). Ophthalmic examinations including assessment of visual acuity and slit lamp examination, should be performed at baseline, before the subsequent 3 treatment cycles and during treatment as clinically indicated. Patients experiencing corneal adverse reactions may require dose modifications or treatment discontinuation based on severity of findings. Cases of corneal ulcer (ulcerative and infective keratitis) have been reported with BLENREP. These should be managed promptly and treatment with BLENREP should be interrupted until the corneal ulcer has healed. Due to the risk of thrombocytopenic events, complete blood counts should be obtained at baseline and monitored during treatment. Patients on concomitant anticoagulant treatments may require more frequent monitoring and should be managed with a dose delay or reductions. If a moderate or severe infusion-related reaction occurs, interrupt infusion and provide supportive treatment. Once symptoms resolve, resume at a lower infusion rate. If anaphylactic or life-threatening infusion reaction, BLENREP should be permanently discontinued. Undesirable effects: The most commonly-reported adverse reactions were keratopathy and thrombocytopenia. The most commonly reported serious adverse reactions were pneumonia, pyrexia and infusion related reactions. Very common (=1/10):? Pneumonia, thrombocytopenia, anaemia, lymphopenia, leukopenia, neutropenia, keratopathy, blurred vision events, dry eye, nausea, diarrhoea, pyrexia, fatigue, increased aspartate aminotransferase, increased gamma glutamyltransferase and infusion related reactions. Common (=1/1000 to <1/10): Upper respiratory tract information, photophobia, eye irritation, vomiting and increased creatine phosphokinase Refer to the BLENREP Prescribing Information for a full list of adverse events and the complete important safety information.

GSK in Oncology

GSK is focused on maximising patient survival through transformational medicines. GSK?s pipeline is focused on immuno-oncology, cell therapy, cancer epigenetics, and synthetic lethality. Our goal is to achieve a sustainable flow of new treatments based on a diversified portfolio of investigational medicines utilising modalities such as small molecules, antibodies, antibody drug conjugates and cells, either alone or in combination.

About GSK

GSK is a science-led global healthcare company with a special purpose: to help people do more, feel better, live longer. For further information please visit?www.gsk.com/about-us. Cautionary statement regarding forward-looking statements GSK cautions investors that any forward-looking statements or projections made by GSK, including those made in this announcement, are subject to risks and uncertainties that may cause actual results to differ materially from those projected. Such factors include, but are not limited to, those described under Item 3.D "Risk Factors" in the company's Annual Report on Form 20-F for 2019 and as set out in GSK?s ?Principal risks and uncertainties? section of the Q2 Results and any impacts of the COVID-19 pandemic. [1]?Trudel S, Lendvai N, Popat R, et al. Antibody?drug conjugate, GSK2857916, in relapsed/refractory multiple myeloma: an update on safety and efficacy from dose expansion phase I study. Blood Cancer Journal. 2019;9(4). DOI:10.1038/s41408-019-0196-6. [2]?Multiple Myeloma. World Health Organization International Agency for Research on Cancer. https://gco.iarc.fr/today/data/factsheets/cancers/35-Multiple-myeloma-fact-sheet.pdf. Accessed August 2020. [3]?Nooka A, Kastritis E, Dimopoulos M, Lonial S. Treatment options for relapsed and refractory multiple myeloma. Blood. 2015;125(20):3085-3099. DOI:10.1182/blood-2014-11-568923. [4]?Lonial, S, et al. Belantamab mafodotin for relapsed or refractory multiple myeloma (DREAMM-2): a two-arm, randomised, open-label, phase 2 study. Lancet Oncol. 2020; 21(2):207?21.