1. Male or female, 18 years or older, capable of giving consent.
2. Have confirmed MM as defined by IMWG criteria.
3. ECOG Performance Status 0-2.
4. Have had at least 1 and no more than 3 prior lines of therapy.
5. Must have measurable disease defined as at least one of:
o Serum M-protein concentration of greater than or equal to 5g/L
o Urine M-protein excretion greater than or equal to 200mg/24hr or
o Serum free light chain (FLC) assay: involved FLC level greater than or equal to 100mg/L and an abnormal serum free light chain ration (less than 0.26 or greater than 1.65)
6. Adequate organ system function:
o Haematological (transfusion and/or growth factor support within 2 weeks are not permitted for the purpose of meeting eligibility criteria):
- Absolute neutrophil greater than or equal to 1.0x10^9/L
- Haemoglobin greater than or equal to 80g/L
- Platelet greater than or equal to 50x10^9/L
- ALT less than 2.5xULN
- Bilirubin unless than 1.5xULN (Isolated bilirubin greater than or equal to 1.5xULN is acceptable if bilirubin is fractionated and direct bilirubin less than 35%)
- eGFR greater than 30ml/min
- Spot urine (albumin/creatinine ratios) less than 500 mg/g (56 mg/mmol)
- LVEF greater than 45%
7. Female participants: contraceptive use should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies.
A female participant is eligible to participate if she is not pregnant or breastfeeding, and at least one of the following conditions applies:
- Is not a woman of childbearing potential (WOCBP)
- Is a WOCBP and using a contraceptive method that is highly effective (with a failure rate of less than 1% per year), preferably with low user dependency (as described in Appendix 6), during the intervention period and for at least 4 months after the last dose of study intervention and agrees not to donate eggs (ova, oocytes) for the purpose of reproduction during this period. The investigator should evaluate the effectiveness of the contraceptive method in relationship to the first dose of study intervention. A WOCBP must have a negative highly sensitive serum pregnancy test (as required by local regulations) within 72 hours before the first dose of study intervention.
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.
Non-childbearing potential is defined as follows (by other than medical reasons):
- greater than or equal to 45 years of age and has not had menses for greater than 1 year.
- Patients who have been amenorrhoeic for less than 2 years without history of a hysterectomy and oophorectomy must have a follicle stimulating hormone value in the postmenopausal range upon screening evaluation.
? - Post-hysterectomy, post-bilateral oophorectomy, or post-tubal ligation. Documented hysterectomy or oophorectomy must be confirmed with medical records of the actual procedure or confirmed by an ultrasound. Tubal ligation must be confirmed with medical records of the actual procedure.
8. Male participants: contraceptive use should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies.
Male participants are eligible to participate if they agree to the following during the intervention period and for 6 months after the last dose of study treatment to allow for clearance of any altered sperm:
- Refrain from donating sperm.
- Be abstinent from heterosexual intercourse as their preferred and usual lifestyle (abstinent on a long term and persistent basis) and agree to remain abstinent.
- Must agree to use contraception/barrier as detailed below:
Agree to use a male condom, even if they have undergone a successful vasectomy, and female partner to use an additional highly effective contraceptive method with a failure rate of less than 1% per year as when having sexual intercourse with a woman of childbearing potential (including pregnant females).
9. All prior treatment-related toxicities (defined by National Cancer Institute- Common Toxicity Criteria for Adverse Events (NCI-CTCAE), version 5.0) must be equal to Grade 1 at the time of enrolment except for alopecia.
10. Participant must be able to understand the study procedures and agree to participate in the study by providing written informed consent.
Participants must not have had/be:
1. Systemic anti-myeloma therapy within ?14 days with the exception of corticosteroids equivalent to dexamethasone ?160mg in total within last 4 weeks.
2. Prior treatment with mAb (except for mAb for COVID-19 prophylaxis or management) within 30 days of receiving first dose of study drugs
3. Evidence of cardiovascular risk:
- Evidence of current clinically significant untreated arrhythmias, including clinically significant ECG abnormalities such as 2nd degree (Mobitz Type II) or 3rd degree atrioventricular (AV) block; Clinically significant, uncontrolled arrhythmias
- History of myocardial infarction, acute coronary syndrome (including unstable angina), coronary angioplasty, or stenting or bypass grafting within last 6 months;
- Class III or IV heart failure defined by New York Heart Association functional classification system.
- Uncontrolled hypertension
4. Pregnant or lactating females.
5. Active infection requiring treatment.
6. Known HIV infection.
7. Active Hepatitis B infection. Patients with positive HBcAB and negative HBsAg are eligible provided HBV DNA is negative.
8. Positive hepatitis C antibody and positive hepatitis C RNA at screening or within 3 months prior to first dose of study treatment. (NOTE: participants with positive hepatitis C antibody due to prior resolved disease can be enrolled only if confirmatory negative hepatitis C RNA is obtained.).
9. Current corneal epithelial disease except for mild changes in corneal epithelium
10. Known immediate or delayed hypersensitivity reaction or idiosyncratic reaction to belantamab mafodotin..
11. Ongoing grade 2 or higher peripheral neuropathy.
12. Known immediate or delayed hypersensitivity reaction to proteasome inhibitors, or unacceptable adverse effects from previous proteasome inhibitors.
13. Participant must not have current unstable liver or biliary disease defined by the presence of ascites, encephalopathy, coagulopathy, hypoalbuminemia, oesophageal 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.
14. Participant must not have presence of active renal condition (infection, requirement for dialysis or any other condition that could affect participant’s safety). Participants with isolated proteinuria resulting from MM are eligible, provided they fulfil inclusion criteria.
15. Participant must not use contact lenses while participating in this study.
16. Participant must not be simultaneously enrolled in any interventional clinical trial.
17. Participant must not have used an investigational drug or approved systemic anti-myeloma therapy (including systemic steroids) within 14 days or five half-lives, whichever is shorter, preceding the first dose of study drug.
18. Participant must not have had plasmapheresis within 7 days prior to first dose of study treatment.
19. Participant must not have had major surgery = 4 weeks prior to initiating study treatment.
20. Participant must not have any evidence of active mucosal or internal bleeding.
21. Participant must not have invasive malignancies other than disease under study, unless the second malignancy has been medically stable for at least 2 years and, in the opinion of the principal investigators, will not affect the evaluation of the effects of clinical trial treatments on the currently targeted malignancy. Participants with curatively treated non-melanoma skin cancer may be enrolled without a 2-year restriction.
22. Participant must not have 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.