A Study of Carfilzomib Plus Dexamethasone in Adults With Relapsed or Refractory Multiple Myeloma at US Community Oncology Centers

Inclusion Criteria:

* Subject has provided informed consent prior to initiation of any study specific activities/procedures.
* Males or females greater than or equal to 18 years of age.
* Relapsed MM after last treatment or refractory while receiving non-proteasome inhibitor therapy.
* Measurable disease with at least 1 of the following assessed within 21 days prior to enrollment:

  * Immunoglobulin G (IgG) MM: serum monoclonal protein (M-protein) level ≥ 1.0 g/dL
  * IgA, IgD, IgE multiple myeloma: serum M protein level ≥ 0.5 g/dL
  * Urine M-protein ≥ 200 mg per 24 hours
  * In subjects without measurable serum or urine M-protein, serum free light chain (SFLC) ≥ 100 mg/L (involved light chain) and an abnormal serum kappa lambda ratio.
* Eastern Cooperative Oncology Group Performance Status (ECOG PS) of 0 to 1.
* Subjects must have at least partial response (PR) to at least 1 line of prior therapy.
* Subjects must have received at least 1 but not more than 3 prior lines of therapy for MM (induction therapy followed by stem cell transplant and consolidation/maintenance therapy will be considered as 1 line of therapy).
* Prior therapy with a proteasome inhibitor (PI) is allowed as long as the subject had at least a PR to most recent therapy with PI, was not removed due to toxicity (except for neuropathy), did not relapse within 60 days from discontinuation of PI, and will have at least a 6-month PI treatment-free interval from last dose received until enrollment. (Subjects may receive maintenance therapy with drugs that are not PI during this 6-month PI treatment-free interval).

Exclusion Criteria:

* Waldenström macroglobulinemia.
* Multiple myeloma of IgM subtype.
* POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes).
* History of plasma cell leukemia.
* Primary amyloidosis (patients with multiple myeloma with asymptomatic deposition of amyloid plaques found on biopsy would be eligible if all other criteria are met).
* Subjects with nephrotic range proteinuria (greater than or equal to 3 g albumin for 24 hours urine OR greater than or equal to 2 g albumin/1 g of creatinine on a random urine specimen).
* Myelodysplastic syndrome.
* History of other malignancy within the past 5 years, with the following exceptions:

  * Malignancy treated with curative intent and with no known active disease present for greater than or equal to 3 years before enrollment and felt to be at low risk for recurrence by the treating physician.
  * Adequately treated non-melanoma skin cancer or lentigo maligna without evidence of disease.
  * Adequately treated cervical carcinoma in situ without evidence of disease.
  * Adequately treated breast ductal carcinoma in situ without evidence of disease.
  * Prostatic intraepithelial neoplasia without evidence of prostate cancer.
  * Adequately treated urothelial papillary noninvasive carcinoma or carcinoma in situ.
  * Treated medullary or papillary thyroid cancer.
  * Similar neoplastic conditions with an expectation of greater than 95% five-year disease-free survival.
* Known human immunodeficiency virus (HIV) infection, hepatitis C infection (subjects with hepatitis C that achieve a sustained virologic response following antiviral therapy are allowed), or hepatitis B infection (subjects with hepatitis B surface antigen or core antibody that achieve sustained virologic response with antiviral therapy directed at hepatitis B are allowed).
* Acute or chronic graft-versus-host disease (any grade).
* Acute active infection requiring systemic antibiotics, antifungal, antiviral (except antiviral therapy directed at hepatitis B) agents within 14 days prior to enrollment.
* Known cirrhosis.
* Significant neuropathy (grades 3 to 4, or grade 2 with pain) within 14 days prior to enrollment.
* Subjects with pleural effusions requiring thoracentesis or ascites requiring paracentesis within 14 days prior to enrollment.
* Uncontrolled hypertension, defined as an average systolic blood pressure ≥ 160 mmHg or diastolic ≥ 100 mmHg. Subjects with controlled hypertension are eligible.
* Hepatic dysfunction within 21 days prior to enrollment: bilirubin 1.5 times the upper limit of normal (ULN) aspartate aminotransferase (AST) or alanine aminotransferase (ALT) 3 times the ULN
* Active congestive heart failure with or without reduced ejection fraction (New York Heart Association \[NYHA\] Class III to IV), symptomatic ischemia, uncontrolled arrhythmias, clinically significant electrocardiogram (ECG) abnormalities, screening ECG with corrected QT interval (QTc) of greater than 470 msec, pericardial disease, myocardial infarction within 4 months prior to enrollment.
* Known chronic obstructive pulmonary disease.
* Known interstitial pneumonitis.
* Immunotherapy within 21 days prior to enrollment.
* Chemotherapy with approved anticancer therapeutic within 21 days prior to enrollment.
* Glucocorticoid therapy (prednisone greater than 30 mg/day or equivalent) within 14 days prior to enrollment.
* Focal radiation therapy within 7 days prior to enrollment. Radiation therapy to an extended field involving a significant volume of bone marrow within 21 days prior to enrollment (ie, prior radiation must have been to less than 30% of the bone marrow).
* Major surgery (except kyphoplasty) within 28 days prior to enrollment.
* Autologous or allogeneic stem cell transplant within 90 days prior to enrollment.
* Contraindication to dexamethasone.
* Known history of allergy to Captisol (a cyclodextrin derivative used to solubilize carfilzomib).
* Intolerance to intravenous (IV) hydration.
* Currently receiving treatment in another investigational device or drug study, or less than 30 days since ending treatment on another investigational device or drug study(ies). Other investigational procedures while participating in this study are excluded.
* Hepatic dysfunction within 21 days prior to enrollment: bilirubin greater than or equal to 1.5 times the upper limit of normal (ULN); aspartate aminotransferase (AST) or alanine aminotransferase (ALT) greater than or equal to 3 times the ULN.
* Left ventricular ejection fraction less than 40% assessed by transthoracic echocardiogram.
* Severe valvular disease assessed by transthoracic echocardiogram.
* Severe right-ventricular dysfunction assessed by transthoracic echocardiogram.
* Right-ventricular systolic pressure greater than 40 mm Hg assessed by transthoracic echocardiogram.
* Screening absolute neutrophil count (ANC) should be independent of growth factor support for greater than or equal to 1 week.
* Hemoglobin less than 80 g/L within 21 days prior to enrollment. Use of erythropoietic stimulating factors and red blood cell (RBC) transfusions per institutional guidelines is allowed, however most recent RBC transfusion may not have been done within 7 days prior to obtaining screening hemoglobin.
* Platelet count \< 50 x 10\^9/L (≤ 30 x 10\^9/L if myeloma involvement in the bone marrow is \> 50%) within 21 days prior to enrollment. Subjects should not have received platelet transfusions for at least 1 week prior to obtaining the screening platelet count.
* Estimated glomerular filtration rate (GFR) less than 30 mL/min/1.73 m\^2 (per the Chronic Kidney Disease Epidemiology Collaboration formula) within 21 days prior to enrollment.