Daratumumab, Ixazomib, and Dexamethasone in Treating Participant With Amyloid Light Chain Amyloidosis

PRIMARY OBJECTIVES:

I. To confirm the safety and tolerability of daratumumab, ixazomib, and dexamethasone (DId)
in patients with amyloid light chain (AL) amyloidosis.

II. To determine the recommended phase 2 dose (RP2D) of daratumumab, ixazomib, and
dexamethasone in subjects with AL amyloidosis.

SECONDARY OBJECTIVES:

I. To determine the hematologic response rate of daratumumab, ixazomib, and dexamethasone in
patients with AL amyloidosis.

II. To determine cardiac and renal organ response rate of daratumumab, ixazomib, and
dexamethasone in patients with AL amyloidosis.

III. To determine time to next therapy. IV. To determine the time to response. V. To
determine the duration of response. VI. To determine progression free survival (PFS). VII. To
determine overall survival (OS).

OUTLINE: This is a dose-escalation study of dexamethasone.

Participants receive daratumumab intravenously (IV) over 3.5-6.5 hours on days 1, 8, 15, and
22 of courses 1-2, on days 1 and 15 of courses 3-6, and on day 1 of courses 7-12.
Participants also receive ixazomib orally (PO) on days 1, 8, and 15, and dexamethasone IV
over 15 minutes or PO on days 1, 8, 15, and 22. Treatment repeats every 28 days for up to 12
courses in the absence of disease progression or unaccepted toxicity.

After completion of study treatment, participants are followed up at 30 days and then every
90 days for 24 months.

Inclusion Criteria:

- Diagnosis of primary systemic AL amyloidosis of tissue as determined by: a. Congo red
staining of tissue showing apple green birefringence AND b. Clonal plasma cell
disorder as determined by: i. Immunohistochemistry, in situ hybridization (ISH) or
flow cytometry demonstrating kappa or lambda light chain restriction on bone marrow
biopsy AND/OR ii. Monoclonal protein on serum or urine electrophoresis/immunofixation
OR abnormal free light chain ratio

- Newly diagnosed OR AL amyloidosis. Newly diagnosed patients must be treatment naive
without previous plasma cell-directed therapy with the exception of a maximum of 160
mg dexamethasone or equivalent prior to dosing on protocol. Relapsed and/or refractory
is defined as follows: a. Clonal relapse after at least one previous line of therapy
or high-dose chemotherapy and autologous stem cell transplantation OR b. Refractory
disease to prior therapy defined as less than a hematologic very good partial response
(VGPR). If previous therapy was autologous stem cell transplant (SCT), must be >= 3
months after SCT

- Measurable disease defined by: a. Monoclonal protein in the serum or urine by
immunofixation OR plasmacytosis of bone marrow with monoclonal staining for kappa or
lambda light-chain isotype b. dFLC >= 50 mg/L (dFLC=difference in involved and
uninvolved serum free light-chain levels)

- 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 patient at any time without prejudice to future medical care

- Female patients 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
form through 90 days after the last dose of study drug, OR

- Agree to practice true abstinence when this is in line with the preferred and
usual lifestyle of the patient. (Periodic abstinence [eg, calendar, ovulation,
symptothermal, post-ovulation methods] and withdrawal are not acceptable methods
of contraception)

- Male patients, even if surgically sterilized (ie, status post-vasectomy), must agree
to one of the following:

- 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 when this is in line with the preferred and
usual lifestyle of the patient. (Periodic abstinence [eg, calendar, ovulation,
symptothermal, post-ovulation methods] and withdrawal are not acceptable methods
of contraception)

- Eastern Cooperative Oncology Group (ECOG) performance status and/or other performance
status 0, 1, or 2

- Absolute neutrophil count (ANC) >= 1,000/mm^3

- Platelet count >= 75,000/mm^3. Platelet transfusions to help patients meet eligibility
criteria are not allowed within 3 days before study enrollment

- 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 >= 10 mL/min

Exclusion Criteria:

- Non-AL amyloidosis

- Clinically overt myeloma a.) Lytic bone lesions or biopsy proven plasmacytoma b.)
Hypercalcemia (corrected for albumin) > 11 mg/dL unexplained by other causes

- Clinically significant cardiac disease defined by any of the following criteria: a.)
New York Heart Association (NYHA) class IV heart failure b.) N-terminal prohormone of
brain natriuretic peptide (NT-ProBNP) > 8500 ng/L c.) Symptomatic orthostatic
hypotension with supine systolic blood pressure < 90 mm Hg d.) Unstable cardiac
arrhythmia e.) Unstable angina f.) Myocardial infarction within the past 6 months

- Severe obstructive airway disease defined by forced expiratory volume at one second
(FEV1) < 50%

- Female patients who are lactating or have a positive serum pregnancy test during the
screening period

- Failure to have fully recovered (ie, =< grade 1 toxicity) from the reversible effects
of prior chemotherapy

- Major surgery within 14 days before enrollment

- Radiotherapy within 14 days before enrollment. If the involved field is small, 7 days
will be considered a sufficient interval between treatment and administration of the
ixazomib

- Infection requiring systemic intravenous antibiotic therapy or other serious infection
within 14 days before study enrollment

- Systemic treatment, within 14 days before the first dose of and dexamethasone (DId),
with strong CYP3A inducers (rifampin, rifapentine, rifabutin, carbamazepine,
phenytoin, phenobarbital), or use of Ginkgo biloba or St. John's wort

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

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

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

- Known gastrointestinal (GI) disease or GI procedure that could interfere with the oral
absorption or tolerance of ixazomib including difficulty swallowing

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

- Patient has >= grade 3 peripheral neuropathy, or grade 2 with pain on clinical
examination during the screening period

- Participation in other clinical trials, including those with other investigational
agents not included in this trial, within 30 days of the start of this trial and
throughout the duration of this trial

- Patients that have previously been treated with daratumumab or ixazomib, or
participated in a study with ixazomib whether treated with ixazomib or not

- Planned high-dose chemotherapy and autologous stem cell transplantation within 6
28-day treatment cycles after starting on treatment