GSK announces FDA advisory committee votes in favour of positive benefit/risk profile for belantamab mafodotin for patients with relapsed/refractory multiple myeloma

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Issued: London UK – LSE Announcement

• Recommendation based on review of DREAMM clinical trial programme, including the pivotal DREAMM-2 study

• If approved, belantamab mafodotin will be a first-in-class anti-BCMA therapy for the treatment of relapsed/refractory multiple myeloma

GlaxoSmithKline today announced the US Food and Drug Administration (FDA) Oncologic Drugs Advisory Committee (ODAC) voted 12-0 in favour of the demonstrated benefit of monotherapy treatment with belantamab mafodotin outweighing the risks for patients with relapsed or refractory multiple myeloma who have received at least four prior therapies including an immunomodulatory agent, a proteasome inhibitor and an anti-CD38 antibody. Two committee members could not participate in the final vote.

Dr Axel Hoos, Senior Vice President and Head of Oncology R&D, GSK said: “We are pleased the committee recognised the potential for belantamab mafodotin to help patients who have relapsed or refractory multiple myeloma, an incurable disease with limited treatment options. We look forward to working with the FDA as they complete their review of our Biologics License Application.”

The recommendation was based on data from the DREAMM (DRiving Excellence in Approaches to Multiple Myeloma) clinical trial programme, including the pivotal DREAMM-2 study which enrolled heavily pre-treated patients who had actively progressing multiple myeloma that had worsened despite current standard of care.[i] The six-month primary results from the study were published in The Lancet Oncology in December 2019 and serve as the basis for the Biologics License Application (BLA).

The FDA will consider the recommendation of the committee but is not obligated to follow it. The FDA granted breakthrough therapy designation to belantamab mafodotin in 2017 and priority review designation for the BLA earlier this year. A Marketing Authorisation Application for belantamab mafodotin also is under accelerated assessment by the European Medicines Agency.

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

About belantamab mafodotin (GSK2857916)

Belantamab mafodotin is an investigational 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.

About DREAMM-2

DREAMM-2 is an open label study of belantamab mafodotin. 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 belantamab mafodotin every three weeks. 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 belantamab mafodotin.

About multiple myeloma

Multiple myeloma is the second most common blood cancer in the US and is generally considered treatable, but not curable.^[ii] Research into new therapies is needed as multiple myeloma commonly becomes refractory to available treatments.^[iii]

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.ⁱⁱⁱ

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 any impacts of the COVID-19 pandemic.

[i] 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.

[ii] 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.

[iii] 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.