The goal of this observational study is to learn about antithrombotic regimens in Multiple myeloma patients. The main question it aims to answer is the efficacy of different types of thromboprophylaxis (antiplatelet agents, heparins, oral anticoagulants) in preventing venous thromboembolism (VTE).

This is an observational prospective cohort study aimed at assessing the efficacy of different types of thromboprophylaxis in MM patients; the setting is the GIMEMA network of the Italian haematological Centers.

The observation time for each patient will be of 3 years from the start of the active treatment for MM. Patients will remain in the study regardless of the stage of disease, type of treatment (induction, transplantation, maintenance), type of antithrombotic prophylaxis, occurrence of thrombosis.

Four cohorts will be identified: cohort 1 will include patients without thromboprophylaxis, cohort 2 will include patients receiving antiplatelet agents, cohort 3 will include patients receiving heparins, and cohort 4 will include patients receiving oral anticoagulants.

Inclusion Criteria:

1. Age equal to or greater than 18 years of age.
2. New diagnosis of symptomatic MM according to the CRAB or the SLIM criteria of the International Myeloma Working Group
3. First active treatment for MM started after recruitment in the study
4. Signed informed consent

Exclusion Criteria:

1. Patients having had thrombosis within 6 months before diagnosis of MM
2. Patients with need of combined antithrombotic regimens (i.e. VKA or DOAC or LMWK and one or two antiplatelet drugs)
3. Ongoing first active treatment for MM initiated before the starting of the study.

Adult patients with a newly diagnosis of symptomatic Multiple myeloma treated at the Italian haematological Centers of the GIMEMA network. Patients will be enrolled prior to any treatment for MM.