1. The presence of only extramedullary lesions as determined by imaging performed within 4 weeks of start of trial.
2. Significant renal (infection, requirement for dialysis or any other condition that could affect participant’s safety) or hepatic (current unstable liver or biliary disease defined by the presence of ascites, encephalopathy, coagulopathy, hypoalbuminemia, esophageal or gastric varices, persistent jaundice, or cirrhosis. Note: Stable non-cirrhotic chronic liver disease (including Gilbert’s syndrome or asymptomatic gallstones) or hepatobiliary involvement of malignancy is acceptable if otherwise meets entry criteria) impairment.
3. Participants with isolated proteinuria resulting from MM are eligible, provided they fulfil inclusion criteria
4. Participant with life expectancy of less than 6 months.
5. Any other significant disease or disorder which, in the opinion of the Investigator, may either put the participants at risk because of participation in the trial, or may influence the result of the trial, or the participant’s ability to participate in the trial.
6. Participants who have participated in another research trial involving an unlicensed product in the past 12 weeks.
7. Participants that have undertaken more than two rounds of chemotherapy.
8. Patients who would not be able to tolerate lying supine, within the gantry of a PET-CT scanner, with a total duration of up to 1 hour.
9. The investigator is responsible for review of medical history, menstrual history, and recent sexual activity to decrease the risk for inclusion of a woman with a nearly undetected pregnancy.
10. Participant currently has corneal epithelial disease, except nonconfluent superficial punctate keratitis (SPK).
11. Patients with ongoing or recent BCMA targeted myeloma treatment which can be expected to affect lesion BCMA expression.
12. Participant must not have used an investigational anti-myeloma drug within 14 days or five half-lives, whichever is shorter, preceding the first dose of study drug.
13. Participant must not have evidence of cardiovascular risk including any of the following:
13.1. Evidence of current clinically significant uncontrolled arrhythmias, including clinically significant ECG abnormalities such as 2nd degree (Mobitz Type II) or 3rd degree atrioventricular (AV) block.
13.2. History of myocardial infarction, acute coronary syndromes (including unstable angina), coronary angioplasty, or stenting or bypass grafting within three (3) months of Screening.
13.3. QTcF interval >450 msec (QT interval corrected for heart rate according to Fridericia’s formula), and/or hypokalemia, and/or family history of long QT syndrome.
13.4. Class III or IV heart failure as defined by the New York Heart Association functional classification system, [NYHA, 1994]
13.5. Uncontrolled hypertension
14. Known immediate or delayed hypersensitivity reaction or idiosyncrasy to drugs chemically related to belantamab or any of the components of the study treatment. History of severe hypersensitivity to other mAbs.
15. Smouldering MM, Symptomatic amyloidosis, active POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma proliferative disorder, skin changes) or active plasma cell leukaemia at the time of screening.
16. Any serious and/or unstable pre-existing medical, psychiatric disorder or other conditions (including lab abnormalities) that could interfere with participant’s safety, obtaining informed consent or compliance to the study procedures.
17. Participant must not have received a live or live-attenuated vaccine within 30 days prior to first dose of belantamab.
18. Patients may not be enrolled on BCMA therapeutic clinical trials for treatment whilst on this study.
19. Ongoing Grade 2 or higher peripheral neuropathy or neuropathic pain.
20. Prior allogenic stem cell transplant. NOTE – Participants who have undergone syngeneic transplant will be allowed, only if no history of GvHD.
21. Any major surgery within 4 weeks prior to the first dose of study drug. Exception allowed for bone stabilizing surgery after consultation with PI.
22. Evidence of active mucosal or internal bleeding.
23. Active infection requiring treatment.
25. Presence of hepatitis B surface antigen (HbsAg), or hepatitis B core antibody (HbcAb), at screening or within 3 months prior to first dose of study treatment. Note: presence of Hep B surface antibody (HBsAb) indicating previous vaccination will not exclude a participant.
26. Positive hepatitis C antibody test result or positive hepatitis C RNA test result at screening or within 3 months prior to first dose of study treatment.