The purpose of the study is to investigate the pharmacokinetics of oral dosage of Posaconazole which is routinely administered as a standard care prophylaxis for patients undergoing cancer treatments.

Participants receiving Posaconazole prophylaxis for invasive fungal infection while undergoing cancer treatment will be required to sign an informed consent and donate blood samples for the study. Posaconazole is routinely administered as a prophylaxis using the oral tablet formulation (300mg once daily) as a standard care. Each prophylaxis course-duration will be defined according to local policy at each hospital. In general, Posaconazole prophylaxis commences prior to or with induction or consolidation chemotherapy in AML/MDS patients and continues until neutrophil recovery. In allo-HSCT setting, Posaconazole prophylaxis routinely commences on the day of transplant or with conditioning chemotherapy and continues for approximately 3 months after transplant, except in patients with initiation of intensive immunosuppression after diagnosis of acute or chronic GVHD, administration will go for at least 16 weeks or until prednisolone dose is less than 10mg per day, whichever is later. If patients are suspected or have proven malabsorption or are required to switch to an alternative antifungal agent such as in the case of suspected invasive fungal infection or Posaconazole toxicity, a switch to intravenous formulation of Posaconazole will take place.

Blood samples will be collected on Days 7, 14 and 21 from the onset of Posaconazole prophylactic treatment. If significant diarrhoea occurs, additional blood samples will be collected twice weekly until symptoms resolve, with the first sample being taken 3 days after the onset of diarrhoea. If gastrointestinal absorption is considered inadequate or invasive fungal infection is suspected and patients are switched either to IV antifungal prophylaxis or antifungal treatment as part of their standard care, a blood sample will be collected 20-24 hours after the last oral Posaconazole dose. Study participants will be followed up with respect to clinical data collection during the blood sample collection period and for up to 7 days after the last dose of Posaconazole for invasive fungal infection follow-up, and for the entire antifungal prescribing period (prophylaxis and/or treatment). Participants with diagnosed invasive fungal infection will be followed up to 30-days post-diagnosis with respect to clinical outcomes.

Inclusion Criteria:

• Adult (≥18 years old) haematology patients receiving Posaconazole prophylaxis in the inpatient setting as standard of care.
• Able to give informed consent.

Exclusion Criteria:

• Unable to give informed consent.