A Study Evaluating Venetoclax (ABT-199) in Multiple Myeloma Subjects Who Are Receiving Bortezomib and Dexamethasone as Standard Therapy

Inclusion Criteria:

- Eastern Cooperative Oncology Group (ECOG) performance score less than or equal to 2

- Participant has documented relapsed or progressive multiple myeloma on or after any
regimen or who are refractory to the most recent line of therapy. Relapsed myeloma is
defined as previously treated myeloma that progresses and requires initiation of
salvage therapy, but does not meet the criteria for refractory myeloma. Refractory
myeloma is defined as disease that is non responsive (failure to achieve minimal
response or development of progressive disease [PD]) while on primary or salvage
therapy, or progresses within 60 days of last therapy.

- Participant must have received prior treatment with at least one, but no more than
three, prior lines of therapy for multiple myeloma. A line of therapy consists of
greater than or equal to 1 complete cycle of a single agent, a regimen consisting of
combination of several drugs, or a planned sequential therapy of various regimens.

- Prior treatment with bortezomib or other proteasome inhibitor is allowed, provided ALL
of the following criteria are met: Disease is NOT refractory to any proteasome
inhibitor, defined as no disease progression (i.e., PD, per IMWG or European Society
for Blood and Marrow Transplantation [EBMT] criteria) while receiving proteasome
inhibitor therapy or within 60 days after the last dose, AND best response achieved
with any proteasome inhibitor therapy (alone or in combination) was at least a PR, AND
participant did not discontinue any proteasome inhibitor due to intolerance or greater
than or equal to Grade 3 related toxicity.

- Participant has measurable disease at Screening, defined as at least one of the
following: Serum M-protein greater than or equal to 0.5 g/dL, OR Urine M-protein
greater than or equal to 200 mg in 24-hours, OR serum immunoglobulin free light chain
(FLC) greater than or equal to 10 mg/dL provided serum FLC ratio is abnormal.

Exclusion Criteria:

- Participant is refractory to any proteasome inhibitor, defined as progression on or
within 60 days of the last dose of a proteasome inhibitor-containing regimen.

- Participant has had prior treatment with proteasome inhibitor within 60 days prior to
first dose of study drug.

- Participant has any of the following conditions:

Non-secretory or oligo-secretory multiple myeloma, active plasma cell leukemia i.e., either
20% of peripheral white blood cells or greater than 2.0 X 10^9/liter (L) circulating plasma
cells by standard differential, waldenstrom's macroglobulinemia, amyloidosis, POEMS
syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin
changes), known Human Immunodeficiency Viral (HIV) infection, active hepatitis B or C
infection based on blood screen tests, significant cardiovascular disease, including
uncontrolled angina, severe or uncontrolled arrhythmia, recent myocardial infarction within
6 months of randomization, or congestive heart failure New York Heart Association (NYHA)
Class greater than or equal to 3, Major surgery within 4 weeks prior to randomization,
acute infections requiring parenteral therapy (antibiotic, antifungal, or antiviral) within
14 days prior to randomization, peripheral neuropathy greater than or equal to Grade 3 or
greater than or equal to Grade 2 with pain within 2 weeks prior to randomization,
uncontrolled diabetes or uncontrolled hypertension within 14 days prior to randomization,
any other medical condition that, in the opinion of the Investigator, would adversely
affect the participant's participation in the study

- Participant has a history of other active malignancies, including myelodysplastic
syndrome (MDS), within the past 3 years prior to study entry, with the following
exceptions: Adequately treated in situ carcinoma of the cervix uteri or the breast,
basal cell carcinoma of the skin or localized squamous cell carcinoma of the skin,
prostate cancer Gleason grade 6 or lower AND with stable Prostate Specific Antigen
(PSA) levels off treatment, previous malignancy with no evidence of disease confined
and surgically resected (or treated with other modalities) with curative intent and
unlikely to impact survival during the duration of the study

- If participant had prior allogeneic stem cell transplant (SCT), participant has
evidence of ongoing graft-versus-host disease (GvHD).