Study of Melflufen + Dex With Bortezomib or Daratumumab in Patients With RRMM

Inclusion Criteria:

1. Male or female, age 18 years or older

2. A prior diagnosis of multiple myeloma with documented disease progression in need of
treatment at time of screening

3. One to four prior lines of therapy

4. Measurable disease defined as any of the following:

- Serum monoclonal protein ≥ 0.5 g/dL by serum protein electrophoresis (SPEP)

- ≥ 200 mg/24 hours of monoclonal protein in the urine on 24-hour urine
electrophoresis (UPEP)

- Serum free light chain (SFLC) ≥ 10 mg/dL AND abnormal serum kappa to lambda free
light chain ratio

5. Life expectancy of ≥ 6 months

6. ECOG performance status ≤ 2. (Patients with lower performance status based solely on
bone pain secondary to multiple myeloma may be eligible following consultation and
approval of the medical monitor)

7. Patient is a female of childbearing potential (FCBP)* with a negative serum or urine
pregnancy test prior to initiation of therapy and agrees to practice appropriate
methods of birth control, or the patient is male and agrees to practice appropriate
methods of birth control

8. Ability to understand the purpose and risks of the study and provide signed and dated
informed consent

9. 12-lead Electrocardiogram (ECG) with QT interval calculated by Fridericia Formula
(QTcF) interval of ≤ 470 msec

10. Adequate organ function with the following laboratory results during screening (within
21 days) and immediately before study drug administration on Cycle 1 Day 1:

- Absolute neutrophil count (ANC) ≥ 1,000 cells/mm3 (1.0 x 109/L) (Growth factors
cannot be used within 10 days (14 days for pegfilgrastim) prior to initiation of
therapy)

- Platelet count ≥ 75,000 cells/mm3 (75 x 109/L) (without required transfusions
during the 10 days prior to initiation of therapy)

- Hemoglobin ≥ 8.0 g/dl (red blood cell (RBC) transfusions are permitted)

- Total Bilirubin ≤ 1.5 x upper limit of normal (ULN), or patients diagnosed with
Gilbert's syndrome, that have been reviewed and approved by the medical monitor

- AST/SGOT and ALT/SGPT ≤ 3.0 x ULN

- Renal function: Estimated creatinine clearance by Cockcroft-Gault formula ≥ 45
mL/min and serum creatinine ≤ 2 mg/dL

11. Must have, or be willing to have an acceptable central catheter. (Port a cath,
peripherally inserted central catheter [PICC] line, or central venous catheter)

- (FCBP) is any sexually mature female who: 1) has not undergone a hysterectomy or
bilateral oophorectomy or 2) has not been naturally postmenopausal (not having
menstrual cycles due to cancer therapy does not rule out childbearing potential)
for at least 24 consecutive months.

Exclusion Criteria:

1. Primary refractory disease (i.e. never responded with ≥ MR to any prior therapy)

2. Evidence of mucosal or internal bleeding and/or are platelet transfusion refractory
(i.e. platelet count fails to increase by > 10,000 cells/mm3 after transfusion of an
appropriate dose of platelets)

3. Any medical conditions that, in the Investigator's opinion, would impose excessive
risk to the patient or would adversely affect his/her participating in this study.
Examples of such conditions are: a significant history of cardiovascular disease
(e.g., myocardial infarction, significant conduction system abnormalities,
uncontrolled hypertension, ≥ Grade 3 thromboembolic event in the last 6 months)

4. Known active infection requiring parenteral or oral anti-infective treatment within 14
days of initiation of therapy

5. Other malignancy diagnosed or requiring treatment within the past 3 years with the
exception of adequately treated basal cell carcinoma, squamous cell skin cancer,
carcinoma in-situ of the cervix or breast or very low and low risk prostate cancer in
active surveillance

6. Pregnant or breast-feeding females

7. Serious psychiatric illness, active alcoholism, or drug addiction that may hinder or
confuse compliance or follow-up evaluation

8. Known human immunodeficiency virus or active hepatitis B or C viral infection

9. Concurrent symptomatic amyloidosis or plasma cell leukemia

10. POEMS syndrome (plasma cell dyscrasia with polyneuropathy, organomegaly,
endocrinopathy, monoclonal protein and skin changes)

11. Previous cytotoxic therapies, including cytotoxic investigational agents, for multiple
myeloma within 3 weeks (6 weeks for nitrosoureas) prior to initiation of therapy. The
use of live vaccines within 30 days before initiation of therapy. IMiDs, PIs and or
corticosteroids within 2 weeks prior to initiation of therapy. Other investigational
therapies and monoclonal antibodies (mAb) within 4 weeks of initiation of therapy
Prednisone up to but no more than 10 mg orally once daily (q.d.) or its equivalent for
symptom management of comorbid conditions is permitted but dose should be stable for
at least 7 days prior to initiation of therapy

12. Residual side effects to previous therapy > Grade 1 prior to initiation of therapy
(Alopecia any grade and/or neuropathy Grade 1 without pain are permitted)

13. Prior peripheral stem cell transplant within 12 weeks of initiation of therapy

14. Prior allogeneic stem cell transplantation with active graft-versus-host- disease

15. Prior major surgical procedure or radiation therapy within 4 weeks of initiation of
therapy (this does not include limited course of radiation used for management of bone
pain within 7 days of initiation of therapy)

16. Known intolerance to the required dose and schedule of steroid therapy as determined
by the investigator