This is a study of two treatment pathways [Standard steroid treatment versus combined steroid and Mycophenolate (MMF)] for subjects with newly diagnosed Immune Thrombocytopenia (ITP). ITP is an illness that causes bruising and bleeding due to a low platelet count (blood cells essential for normal clotting). Patients are first given high dose steroids but most suffer side effects (e.g. difficulty sleeping, weight gain, moods swings, high blood pressure and diabetes). In addition, the majority of patients become ill again when the steroids are stopped - only about 20% stay well long term. ITP is relatively rare, non-cancerous in nature and the rare impact on survival of ITP have prevented it from being a priority for research funding, with first line treatment being unsatisfactory and unchallenged for decades. This underestimates the profound adverse impact an ITP diagnosis and its treatment has on individual patients, many of whom are young.

MMF is often used as the next stage treatment for ITP and it works well. However, it can take up to 2 months to work during which patients continue to be at risk of bleeding, bruising, fatigue and usually need more steroids which they find intolerable. They are required to come to hospital for weekly blood tests and for many this impacts on work. We want to find out whether it would benefit more patients if everyone takes MMF at diagnosis instead of current practice (waiting for the illness to come back). We plan to test this by comparing the current way we treat patients to a new way with patients given MMF right at the start of their treatment. 120 patients from 20 different hospitals will be asked to take part and half will be randomly chosen for the new pathway.

This is a multicentre, randomised clinical trial of MMF with steroid as a first line treatment for participants with ITP against the standard care pathway involving steroids alone as first line treatment. This is not a blinded study, therefore patients and research team will know which treatment arm the participant will be randomised to.

There are no additional appointments or separate trial visits for this trial. Participants will be seen at their usual hospital appointments, which may take slightly longer than they do usually to gather all the information needed to carefully record information for the trial and to see how the participants are.

Participants will be screened and given up to one week of steroid prior to randomisation to enable sufficient time to read information, discuss and ask questions with informed consent in an appropriate setting.

Participants will then be randomised to one of either two treatment pathways below and be asked to complete quality of life questionnaires:

1. Steroid +MMF pathway: 1mg/kg once daily prednisolone 4 days (maximum of 100mg), 40mg once daily 2 weeks, 20mg once daily 2 weeks, 10mg once daily 2 weeks, 5mg once daily 2 weeks then 5mg alternate days 2 weeks then stop, (Dexamethasone 20mg or 40mg daily for 4 days is an alternative option to prednisolone if deemed clinically more appropriate for individual circumstances).

   For the duration of steroid, patients will get a PPI (proton pump inhibitors) or H2 antagonist to protect against gastric bleeding and appropriate bone protection.

   From randomisation (alongside steroid), MMF 500mg twice daily starting dose then increased to 750mg twice daily after 2 weeks if tolerated and 1g twice daily after another 2 weeks if tolerated (4 weeks after starting).

   After 6 months of MMF therapy, all patients who have remained in complete remission (platelet count> 100 x10 9/L) will reduce the dose by 250mg (one capsule) each month. The aim is to continue on the lowest dose that achieves a haemostatic (safe) platelet count (platelet 50-100 x10 9/L) and to ensure that patients who have gone into a spontaneous remission do not continue to take the drug indefinitely.

2. Steroid only group: 1mg/kg once daily prednisolone 4 days (maximum of 100mg), 40mg once daily 2 weeks, 20mg once daily 2 weeks, 10mg once daily 2 weeks, 5mg once daily 2 weeks then 5mg alternate days 2 weeks then stop (Dexamethasone 20mg or 40mg orally daily for 4 days is an alternative option to prednisolone if deemed clinically more appropriate for individual circumstances).

For the duration of steroid, patients will get a PPI (proton pump inhibitors) or H2 antagonist to protect against gastric bleeding and appropriate bone protection.

Patients will be seen at the following time points after randomisation:

2 months, 4 months, 6 months and 12 months when the following procedures will take place:

• Laboratory tests (safety bloods)
• Date of treatment failure (refractory or relapse AND need for second line therapy). [If treatment failure occurs, choice of second line treatment will be individualised according to patient's clinical circumstances. Further steroid will be given according to clinical need. Hospital monitoring of platelet levels is part of routine care for ITP patients and we will collect these details from the medical notes without requiring patients to come in for additional samples to be taken. These locally collected samples may be collected monthly (or less often) for patients believed to be in stable remission and weekly at lower or declining platelet levels. We expect this to allow us to calculate the time in remission and time in relapse with reasonable accuracy over the 12 month follow up period].
• Vital signs
• Blood sugar results
• Medication side effects (including infections)
• Dose and duration of steroids
• Need for rescue or other treatments (including second or third line). [Emergency and rescue treatments will be permitted throughout the study. These include platelet transfusions, tranexamic acid and intravenous immunoglobulin. These are known not to impact on the natural history of ITP and it is recognised that they may be important for patient safety. The use of 'rescue treatments' will be recorded on the CRF]
• Hospital attendances or admissions
• Days off work
• Patient questionnaires: Quality of life assessment
• Immunoglobulins rechecked at 6 months and 12 months

In addition at Screening and 2 months, participants will have the option to give an extra blood sample for the Bristol Biobank (ancillary translational basic science studies). There is an additional patient information sheet and consent form for this. Participants can consent to enter the trial, but decline to have bloods taken for bio banking.

In addition at 6 and 12 months, immunoglobulins will be checked.

Inclusion Criteria:

• Patients (males and females) >16 years old with a diagnosis of ITP, a pl count <30x109/L AND a clinical need for first line treatment.
• Patients have provided written informed consent

Exclusion Criteria:

• The exclusion criteria include pregnancy and breastfeeding
• Patients with HIV, Hepatitis B or C, or Common Variable immunodeficiency.
• Women of child bearing potential require a pregnancy test result within 7 days prior to randomisation (as per 7.1 below) to rule out unintended pregnancy
• Contraindications to MMF or steroid (see SPC, Appendix 2) including patients with hypersensitivity to mycophenolate mofetil, mycophenolic acid or to any of the excipients or active significant infection
• Patients not capable of giving informed consent (e.g. due to incapacity)
• Patients unwilling to follow contraceptive advice if allocated to MMF treatment arm.