Phase 2 Study to Evaluate the Oral Combination of Ixazomib (MLN9708) With Cyclophosphamide and Dexamethasone in Patients With Newly Diagnosed or Relapsed and/or Refractory Multiple Myeloma

Inclusion Criteria:

Each participant with newly diagnosed multiple myeloma (NDMM) must meet all of the
following inclusion criteria to be enrolled in the study:

1. Adult male or female participants 18 years of age or older with a confirmed
diagnosis of symptomatic multiple myeloma (MM) according to standard criteria.

2. Participants for whom cyclophosphamide and dexamethasone treatment is appropriate
and who are considered not eligible for high-dose therapy (HDT)-stem cell
transplantation (SCT) for 1 or more of the following reasons:

- The participant is 65 years of age or older.

- The participant is less than 65 years of age but has significant comorbid
condition(s) that are, in the opinion of the investigator, likely to have a
negative impact on tolerability of HDT-SCT.

Each participant with relapsed and/or refractory multiple myeloma (RRMM) must meet all of
the following inclusion criteria to be enrolled in the study:

1. Adult male or female participants 18 years or older with a confirmed diagnosis of
symptomatic MM either currently or at the time of initial diagnosis, according to
standard criteria, and relapsed and/or refractory disease after 1 to 3 lines of
prior therapy. A participant is considered to have refractory disease if disease
progression occurred during the treatment period or within 60 days of receiving the
last dose of a given therapy. A line of therapy is defined as 1 or more cycles of a
single-agent or combination therapy or a sequence of planned treatments such as
induction therapy followed by autologous stem cell transplantation (ASCT) and then
maintenance therapy.

2. No evidence of graft-versus-host disease for participants who have undergone prior
allogeneic stem cell transplantation.

In addition, all participants (NDMM and RRMM) must meet all of the remaining criteria:

1. Participants must have measurable disease defined by at least 1 of the following 3
measurements:

- Serum M-protein ≥ 1 g/dL (≥ 10 g/L).

- Urine M-protein ≥ 200 mg/24 hours.

- Serum free light chain assay: involved free light chain level ≥ 10 mg/dL (≥ 100
mg/L), provided that the serum free light chain ratio is abnormal.

2. Participants must meet all of the following clinical laboratory criteria:

- Absolute neutrophil count (ANC) ≥ 1000/mm^3 and platelet count ≥ 75,000/mm^3.
Platelet transfusions to help participants meet eligibility criteria are not
allowed within 3 days prior to administration of the study drug.

- Total bilirubin ≤ 1.5 x the upper limit of the normal range (ULN).

- Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 3 x ULN.

- Calculated creatinine clearance (CrCL) ≥ 30 mL/min.

3. Eastern Cooperative Oncology Group performance status of 0, 1, or 2.

4. Female participants who:

- are postmenopausal for at least 1 year before the screening visit, or

- are surgically sterile, or

- If they are of childbearing potential, agree to practice 2 effective methods of
contraception, at the same time, from the time of signing the informed consent
through 90 days after the last dose of study drug, or

- agree to practice true abstinence over the period previously described, when
this is in line with the preferred and usual lifestyle of the participant.
(Periodic abstinence [ie, calendar, ovulation, symptothermal, postovulation
methods] and withdrawal are not acceptable methods of contraception.), and

- adhere to any treatment-specific pregnancy prevention guidelines for
cyclophosphamide and dexamethasone.

5. Male participants, even if surgically sterilized (ie, status post-vasectomy), who:

- agree to practice effective barrier contraception during the entire study
treatment period and through 90 days after the last dose of study drug, or

- agree to practice true abstinence over the period previously described, when
this is in line with the preferred and usual lifestyle of the participant.
(Periodic abstinence [eg, calendar, ovulation, symptothermal, postovulation
methods for the female partner] and withdrawal are not acceptable methods of
contraception.), and

- adhere to any treatment-specific pregnancy prevention guidelines for
cyclophosphamide and dexamethasone.

6. Voluntary written consent must be given before performance of any study-related
procedure not part of standard medical care, with the understanding that consent may
be withdrawn by the participant at any time without prejudice to future medical
care.

7. Suitable venous access for the study-required blood sampling.

8. Is willing and able to adhere to the study visit schedule and other protocol
requirements.

Exclusion Criteria:

1. Prior treatment for multiple myeloma with either standard of care treatment or
investigational regimen (for participants with NDMM only).

NOTE: Prior treatment with corticosteroids (maximum dose of corticosteroids should
not exceed the equivalent of 160 mg of dexamethasone over 14 days. Localized
radiation is permitted as long as it is below a therapeutic level and administered
at least 14 days prior to the first dose of study treatment.

2. Diagnosis of smoldering MM, Waldenström's macroglobulinemia, POEMS (polyneuropathy,
organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes) syndrome,
plasma cell leukemia, primary amyloidosis, myelodysplastic syndrome, or
myeloproliferative syndrome.

3. Central nervous system involvement.

4. Diagnosed or treated for another malignancy within 2 years before the first dose or
previously diagnosed with another malignancy and have any evidence of residual
disease. Participants with nonmelanoma skin cancer or carcinoma in situ of any type
are not excluded if they have undergone complete resection.

5. Peripheral neuropathy Grade 1 with pain or Grade 2 or higher peripheral neuropathy
of any cause on clinical examination during the Screening period.

6. Known gastrointestinal (GI) disease or GI procedure that could interfere with the
oral absorption or tolerance of study drug, including difficulty swallowing.

7. Infection requiring intravenous (IV) antibiotic therapy or other serious infection
within 14 days before the first dose of study drug.

8. Ongoing or active infection, known human immunodeficiency virus (HIV) positive,
active hepatitis B or C infection.

9. Systemic treatment with strong inhibitors of CYP1A2 (fluvoxamine, enoxacin,
ciprofloxacin), strong inhibitors of CYP3A (clarithromycin, telithromycin,
itraconazole, voriconazole, ketoconazole, nefazodone, posaconazole) or strong CYP3A
inducers (rifampin, rifapentine, rifabutin, carbamazepine, phenytoin,
phenobarbital), or use of Ginkgo biloba or St. John's wort within 14 days before the
first dose of study treatment.

10. Known allergy to any of the study medications, their analogues, or excipients in the
various formulations.

11. Major surgery within 14 days before the first dose of study drug. (Note: kyphoplasty
or vertebroplasty is not considered major surgery.)

12. Female participants who are lactating and breastfeeding or have a positive serum
pregnancy test during the Screening period.

13. Any serious medical or psychiatric illness that could, in the investigator's
opinion, potentially interfere with the completion of treatment according to this
protocol.

14. Comorbid systemic illnesses or other severe concurrent disease which, in the
judgment of the investigator, would make the participant inappropriate for entry
into this study or interfere significantly with the proper assessment of safety and
toxicity of the prescribed regimens.

15. Treatment with any investigational products for reasons other than MM within 30 days
before the first dose of study drug.