Melphalan, Prednisone, Thalidomide and Defibrotide in Relapsed Multiple Myeloma Patients

Defibrotide (DF) is a novel orally bioavailable polydisperse oligonucleotide with anti-thrombotic and anti-adhesive effects, which has been shown to be active in various microangiopathies, including the treatment and prophylaxis of veno-occlusive disease. While DF has minimal inhibitory effect on multiple myeloma (MM) in cell isolates, it showed single agent activity on human MM xenografts in SCID/NOD mice and markedly increased responsiveness of MM to cytotoxic agents, including melphalan, cyclophosphamide and dexamethasone in the same models. DF might thus enhance the response rate of Melphalan, Prednisone and Thalidomide, while protecting against the prothrombotic state seen with this combination in the treatment of MM. In this multicenter, open label, non-randomised phase I/II trial, dosing safety and efficacy of melphalan, prednisone, thalidomide, and DF (MPTD) were determined in pts with relapsed/refractory MM.

Primary refractory or pts receiving therapeutic anticoagulation were excluded. Oral melphalan was administered at 0,25 mg/Kg on D1-4, oral prednisone at 1,5 mg/kg on D 1-4, thalidomide was delivered at 50 mg on D1-35 on cycle 1 and at 100 mg from cycle 2 to cycle 6.

Level + 1 DF = 17 mg/Kg i.v. or 2.4 g p.o. D1-4, followed by 1.6 g p.o. through D 35 Level + 2 DF = 34 mg/Kg i.v. or 4.8 g p.o. D 1-4, followed by 3.2 g p.o. through D 35 Level + 3 DF = 51 mg/Kg i.v. or 7.2 g p.o. D 1-4, followed by 4.8 g p.o. through D 35.

Each course was repeated every 35d for a total of 6 courses and no DVT prophylaxis was used.

Inclusion criteria

• Each patient must meet all of the following inclusion criteria to be enrolled in the study:
• Patient is of a legally consenting age as defined by local regulations.
• Patient is, in the investigator(s) opinion willing and able to comply with the protocol requirements.
• Patient has given voluntary written informed consent before performance of any study-related procedure not part of normal medical care, with the understanding that consent may be withdrawn by the patient at any time without prejudice to their future medical care.
• Female patient is either post-menopausal or surgically sterilized or willing to use an acceptable method of birth control (i.e., a hormonal contraceptive, intrauterine device, diaphragm with spermicide, condom with spermicide, or abstinence) for the duration of the study.
• Male patient agrees to use an acceptable method for contraception (i.e., condom or abstinence) for the duration of the study.
• Patient was previously diagnosed with multiple myeloma based on standard criteria (see Section 13.2).
• Patient is relapsed after one line of treatment but less than three lines, including high-dose chemotherapy with stem cell support, conventional poli-chemotherapy, thalidomide- and melphalan-based regimens
• Patient with primary refractory disease will be considered not eligible
• Patient has measurable disease, defined as follows: any quantifiable serum monoclonal protein value (generally, but not necessarily, greater than 1 g/dL of IgG M-Protein and greater than 0.5 g/dL of IgA M-Protein) and, where applicable, urine light-chain excretion of >200 mg/24 hours.
• Patient has a Karnofsky performance status ≥60%.
• Patient has a life-expectancy >3 months.
• Patient has the following laboratory values within 14 days before Baseline (day 1 of the Cycle 1, before study drug administration):
• Platelet count ≥90 x 109/L without transfusion support within 7 days before the test.
• Absolute neutrophil count (ANC) ≥ 1.00 x 109/L without the use of growth factors
• Corrected serum calcium ≤14 mg/dL (3.5 mmol/L).
• Aspartate transaminase (AST): ≤ 2.5 x the upper limit of normal (ULN).
• Alanine transaminase (AST): ≤ 2.5 x the ULN.
• Total bilirubin: ≤ 1.5 x the ULN.
• Calculated or measured creatinine clearance: ≥20 mL/minute

Exclusion criteria

Patients meeting any of the following exclusion criteria are not to be enrolled in the study.

• Any serious medical condition, laboratory abnormality, or psychiatric illness that would prevent the subject from signing the informed consent form.
• Pregnant or beast feeding females.
• Any condition, including the presence of laboratory abnormalities, which places the subject at unacceptable risk if he/she were to participate in the study or confounds the ability to interpret data from the study.
• Use of any other concomitant standard/experimental anti-myeloma drug or therapy
• Known positive for HIV or active infectious hepatitis, type B or C
• Other concurrent anticoagulation treatment