Different Doses of Belantamab Mafodotin

Belantamab mafodotin is a monoclonal antibody, belantamab, linked to a chemotherapy drug, mafodotin. Belantamab is a form of targeted therapy because it attaches to specific molecules (receptors) on the surface of cancer cells, known as BCMA receptors, and delivers mafodotin to kill them. This trial may help researchers determine if alternate doses and dosing schedules work better in preventing certain side effects, such as eye toxicity, and treating patients with recurrent or refractory multiple myeloma.

PRIMARY OBJECTIVE:

I. To assess the grade 3/4 keratopathy-free rate at the time of dose #4 of an alternative dose/dosing schedule of belantamab mafodotin in patients with relapsed or refractory multiple myeloma (RRMM).

SECONDARY OBJECTIVES:

I. To assess the overall response rate (ORR; partial response or better) of an alternative dose/dosing schedule of belantamab mafodotin in patients with RRMM.

II. To assess the safety of an alternative dose/dosing schedule of belantamab mafodotin in patients with RRMM.

III. To assess the time to progression (TTP) of an alternative dose/dosing schedule of belantamab mafodotin in patients with RRMM.

IV. To assess the progression free survival (PFS) with an alternative dose/dosing schedule of belantamab mafodotin in patients with RRMM.

V. To assess the overall survival (OS) with an alternative dose/dosing schedule of belantamab mafodotin in patients with RRMM.

VI. To assess the minimal residual disease (MRD) negativity rate in patients who have achieved a complete response (CR) with an alternative dose/dosing schedule of belantamab mafodotin.

CORRELATIVE AND PHARMACODYNAMIC RESEARCH OBJECTIVES:

I. To assess the association of pre-treatment serum BCMA levels as well as serum BCMA levels throughout treatment with ORR and PFS to an alternative treatment schedule of belantamab mafodotin.

II. To assess the pharmacokinetics of this alternative dose/dosing schedule of belantamab mafodotin.

OUTLINE: Patients are randomized to 1 of 2 groups.

GROUP I: Patients receive low dose belantamab mafodotin intravenously (IV) on day 1 of each cycle. Cycles repeat every 6 weeks in the absence of disease progression or unacceptable toxicity. All patients undergo a computed tomography (CT) scan, a magnetic resonance image (MRI) scan, or a positron emission tomography (PET)/CT scan during screening and patients with plasmacytoma (a multiple myeloma [MM] tumor in bone or soft tissue) also undergo imaging scans on study. Patients undergo bone marrow aspirate and biopsy during screening and on study as well as collection of blood samples throughout the trial.

GROUP II: Patients receive belantamab mafodotin IV on day 1. Cycle repeasts at 3 weeks for the next cycle and then every 6 weeks for subsequent cycles in the absence of disease progression or unacceptable toxicity. All patients undergo a CT scan, a MRI scan, or a PET/CT scan during screening and patients with plasmacytoma (a MM tumor in bone or soft tissue) also undergo imaging scans on study. Patients undergo bone marrow aspirate and biopsy during screening and on study as well as collection of blood samples throughout the trial.

After completion of trial treatment, patients are followed up every 12 weeks for up to 5 years.