Abatacept, Ixazomib Citrate, and Dexamethasone in Treating Patients With Multiple Myeloma Resistant to Chemotherapy

PRIMARY OBJECTIVES:

I. To determine the therapeutic efficacy (as measured by response rate) of abatacept + ixazomib citrate (ixazomib) + dexamethasone in multiple myeloma patients who have relapsed (or who are primary refractory) following treatment with their first proteasome inhibitor-containing regimen (excluding ixazomib), compared to historical controls of ixazomib + dexamethasone.

SECONDARY OBJECTIVES:

I. To assess the toxicity profile of abatacept + ixazomib + dexamethasone in multiple myeloma patients who have relapsed (or who are primary refractory) following treatment with their first proteasome inhibitor-containing regimen, compared to historical controls of ixazomib + dexamethasone.

II. To assess progression-free and overall survival profile of abatacept + ixazomib + dexamethasone in multiple myeloma patients who have relapsed (or who are primary refractory) following treatment with their proteasome inhibitor-containing regimen, compared to historical controls of ixazomib + dexamethasone.

TERTIARY OBJECTIVES:

I. Assess whether myeloma expression of CD28, CD86, serum kynurenine and/or IL-6 are correlated with specific clinical outcomes.

OUTLINE:

Patients receive abatacept intravenously (IV) over 30 minutes on day 1 of course 1, then subcutaneously (SC) on days 2, 8, 15, and 22 of course 1, and then on days 1, 8, 15, and 22 of subsequent courses. Patients also receive ixazomib citrate orally (PO) once daily (QD) on days 1, 8, and 15 and dexamethasone on days 1, 8, 15, and 22. Courses repeat every 28 days in the absence of disease progression or unacceptable toxicity.

After completion of study treatment, patients are followed up at 30 days and then every 3 months thereafter.