Haematological malignancies (HM), also known as blood cancers, are a heterogeneous and complex group of multicausal diseases that can’t be easily diagnosed nor treated. Nowadays most treatments are extremely complex, and advances in patient diagnosis and therapies slow due to the low number of patients per centre. Thus, there is a need to harmonise, store, and analyse the current HM information to speed-up and support the decision-making process for patients’ access to new therapies. HARMONY PLUS takes advantage of the capabilities of the HARMONY Big Data platform to match this unmet needs by expanding its scope to incorporate myeloproliferative neoplasms, including chronic myeloid leukemia, polycythaemia vera, essential thrombocythaemia, and myelofibrosis; and lymphoproliferative disorders, including Hodgkin’s lymphoma, Waldenström macroglobulinemia and all the other rare HMs not covered by HARMONY Project. In parallel, HARMONY PLUS will continue to refine and define the Core Outcome Sets (COS), especially for these new HMs to ensure the use by researchers of useful common outcomes relevant to all stakeholders. As previously accomplished in HARMONY, HARMONY PLUS is committed to pursue the maximum ethical and legal requirements, particularly to ensure patient’s right to privacy. Data-driven research within Europe will be enhanced by converting the current HARMONY platform into an Integrated Services Platform to serve as a valuable tool to support clinical trial design and use of available data as a control arm. This platform, combined with a HaemoDatabank repository with information about HMs patient biological samples across Europe, will facilitate a more efficient research and clinical trial design, and consequently will promote collaborations with recognised databases outside Europe. From the regulatory point of view, HARMONY PLUS will be a valuable technology tool during the evaluation of new treatments and drugs by also considering the patients’ needs.