[caption id="attachment_9277" align="aligncenter" width="747"] Press Release[/caption]

Issued: London, UK GlaxoSmithKline plc (LSE/NYSE: GSK) announced the US Food and Drug Administration (FDA) granted a priority review for the company?s Biologics License Application (BLA) seeking approval of belantamab mafodotin (GSK2857916) for the treatment of patients with relapsed or refractory multiple myeloma whose prior therapy included an immunomodulatory agent, a proteasome inhibitor and an anti-CD38 antibody. The BLA is based on data from the pivotal DREAMM-2 (DRiving Excellence in Approaches to Multiple Myeloma) study, recently published in?The Lancet Oncology, which enrolled heavily pre-treated patients who had actively progressing multiple myeloma that had worsened despite current standard of care.^[1] In 2017, belantamab mafodotin was granted Breakthrough Therapy designation by the FDA, which is intended to facilitate the development of investigational medicines that have shown clinical promise for conditions where there is significant unmet need.

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.^[2]

About multiple myeloma

Multiple myeloma is the second most common blood cancer and is generally considered treatable, but not curable.^[3]?In the US, more than 32,000 people were diagnosed with multiple myeloma last year and nearly 13,000 people died from the disease.^[4]?Research into new therapies is needed as multiple myeloma commonly becomes refractory to available treatments.^[5]

About the DREAMM clinical trial programme for belantamab mafodotin (GSK2857916)

Belantamab mafodotin is an investigational immunoconjugate 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. Belantamab mafodotin is not currently approved for use anywhere in the world.

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 'Principal risks and uncertainties' in the company's Annual Report on Form 20-F for 2018.   References [1]?Lonial, S, et al. Belantamab mafodotin for relapsed or refractory multiple myeloma (DREAMM-2): a two-arm, randomised, open-label, phase 2 study. The Lancet Oncology. Epub ahead of print. [2]?Carpenter RO, Evbuomwan MO et al. B-cell maturation antigen is a promising target for adoptive T-cell therapy of multiple myeloma.?Clin Cancer Res.?2013 Apr 15;19(8):2048-60. [3]?Kazandjian D. Multiple myeloma epidemiology and survival: A unique malignancy. Semin Oncol. 2016;43(6):676?681. doi:10.1053/j.seminoncol.2016.11.004. [4] SEER Cancer Facts & Figures 2019. Available at:?https://seer.cancer.gov/statfacts/html/mulmy.html. Accessed December 19, 2019. [5]?Nooka AK, Kastritis E, Dimopoulos MA. Treatment options for relapsed and refractory multiple myeloma. Blood. 2015;125(20)