A Study of Melflufen in Combination With Dexamethasone in Relapsed Refractory Multiple Myeloma Patients

Melflufen is designed for targeted delivery of alkylating moieties to tumor cells. In
contrast to other alkylating agents that are hydrophilic, the lipophilicity of melflufen
leads to rapid and extensive distribution into tissues and cells. Inside cells, melflufen may
directly bind DNA or is readily metabolized by intracellular peptidases into the well-known
antitumor compound melphalan, or by esterases into des-ethylmelflufen, which also has
alkylating properties. Due to the high activity of peptidases and esterases in human tumor
cells, the formation of melflufen's metabolites is rapid in these cells with subsequent
inflow of more melflufen. Since des-ethylmelflufen and melphalan are relatively hydrophilic,
there is a possibility for intracellular trapping of these alkylators.

Inclusion Criteria:

- Male or female, age 18 years or older

- A prior diagnosis of multiple myeloma with documented disease progression

- Measurable disease based on either of a) serum monoclonal protein by protein
electrophoresis (SPEP), b) monoclonal protein in the urine on 24-hour urine
electrophoresis (UPEP), and/or c) serum immunoglobulin free light chain combined with
abnormal serum immunoglobulin kappa to lambda free light chain ratio

- A minimum of 2 prior lines of therapy including an IMiD and a PI and is refractory to
pomalidomide and/or daratumumab

- Life expectancy of ≥ 6 months

- Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2

- Female of child bearing potential (FCBP) and non-vasectomized male agree to practice
appropriate methods of birth control

- Ability to understand the purpose and risks of the study and provide signed and dated
informed consent and authorization to use protected health information

- 12-lead ECG with QTc interval within defined limit

- Acceptable laboratory results during screening and prior to first study drug
administration of the following parameters: absolute neutrophil count (ANC), platelet
count, hemoglobin, total bilirubin, aspartate transaminase (AST/SGOT) and alanine
transaminase (ALT/SGPT), renal function based on estimated creatinine clearance

- Must have, or accept to have, an acceptable central catheter for infusion of melflufen

Exclusion Criteria:

- Evidence of mucosal or internal bleeding and/or is platelet transfusion refractory

- 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

- Known active infection requiring parenteral or oral anti-infective treatment within
defined period

- Primary refractory disease

- Other malignancy diagnosed or requiring treatment within the defined period with
specific exceptions

- Pregnant or breast-feeding females

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

- Known HIV or active hepatitis B or C viral infection

- Concurrent symptomatic amyloidosis or plasma cell leukemia

- POEMS syndrome [plasma cell dyscrasia with polyneuropathy, organomegaly,
endocrinopathy, monoclonal protein (M-protein) and skin changes]

- Previous cytotoxic therapies, including cytotoxic investigational agents, for multiple
myeloma within defined values prior to start of study treatment

- Residual side effects to previous therapy over specific grade prior to initiation of
therapy

- Prior autologous or allogeneic stem cell transplant within defined period of
initiation of therapy

- Prior allogeneic stem cell transplant with active graft-versus-host- disease (GVHD).

- Prior major surgical procedure or radiation therapy within specified period of the
first dose of study treatment (with defined exception).

- Known intolerance to steroid therapy