This study is being conducted to demonstrate the superiority in progression-free survival (PFS) of dinaciclib compared to ofatumumab in chronic lymphocytic leukemia (CLL) participants with del 17p or in the overall population who are refractory to either fludarabine treatment or chemoimmunotherapy.

Dinaciclib is a cyclin-dependent kinase (CDK) inhibitor, specific for CDK 1, 2, 5 and 9.

Inclusion Criteria:

• Aged 18 years or older
• Confirmed diagnosis of Chronic Lymphocytic Leukemia (CLL)
• Fludarabine or chemoimmunotherapy refractory disease defined as: failing to respond to or relapsed within 6 months of completing fludarabine or another purine analog alone or in combination regimens, or failing to respond to chemoimmunotherapy or relapsed within 24 months of completing therapy with a combination of chemotherapy plus an anti-CD20 monoclonal antibody
• Eastern Cooperative Oncology Group (ECOG) Performance status 0, 1, or 2
• Adequate organ function and laboratory parameters
• Women of child-bearing potential who are not currently sexually active must

agree to use a medically accepted method of contraception should they become

sexually active while participating in the study

Exclusion Criteria:

• Symptomatic brain metastases or primary central nervous system malignancy
• Treatment with a CYP3A4 inhibitor or inducer within 1 week prior to randomization, or any chemotherapy or biologic therapy within 4 weeks prior to randomization
• Known human immunodeficiency virus (HIV) infection or a known HIV-related

malignancy

• Participants with with clinically active hepatitis B or C defined as disease that requires therapy
• Positive test for glucose-6 phosphate dehydrogenase (G6PD) deficiency
• Prior allogeneic bone marrow transplant
• Presence of Richter's transformation
• Indeterminate deletion 17p status
• Previous treatment with ofatumumab, dinaciclib, or other CDK inhibitors
• Active autoimmune anemia or thrombocytopenia unless stable, which is defined as being responsive to corticosteroids or other standard therapy