A Treatment Study Protocol for Participants 0-45 Years With Acute Lymphoblastic Leukaemia

ALLTogether is a European clinical treatment study for acute lymphoblastic leukaemia (ALL) in infants, children and young adults. The aims are to improve survival and quality of survival. In young people, ALL has excellent outcome with an overall survival of about 92% in children and 75% in young adults. Infants with BCP-ALL and KMT2A-rearrangements have a worse outcome and are treated according to separate protocols, but infants with KMT2A-germline and T-cell ALL have acceptable outcome on standard ALL therapy. However, patients still die of disease - from relapse because of under-treatment and a large fraction of patients are also over-treated: All patients risk treatment-related death and some suffer long-term side-effects or secondary cancer. To show improvement with such good survival, large populations are needed.

Study groups from Sweden, Norway, Iceland, Denmark, Finland, Estonia and Lithuania (NOPHO), the UK (UKALL), the Netherlands (DCOG), Germany (COALL), Belgium (BSPHO), Portugal (SHOP), Ireland (PHOAI), and France (SFCE), have designed a common treatment protocol.

The study has a complex clinical trial design with sub-protocols (the randomisations / intervention) connected to a master protocol. The master protocol consists of well established therapy-elements and in its design typical for current ALL therapy. The master protocol therapy is in the study design considered as standard of care (SOC) therapy for infants, children and young adults with ALL.

The study structure is defined by a master protocol onto which randomised and interventional sub-protocols as well as sub-studies may be added, run and stop in a modular fashion.

The randomisations / intervention may identify therapy that is less toxic, but equally efficacious for sub-groups of patients and innovative therapy that may reduce relapses and death from ALL. In the master protocol, improved risk-stratification is likely to increase survival and reduce unnecessary toxicity and the introduction of therapeutic drug monitoring (TDM) of Asparaginase activity will make the use of Asparaginase more rational and efficient and may thus improve overall outcomes.

The investigators hypothesise that patients stratified to the standard-risk group are over-treated. Therefore, it will be tested if the treatment can be safely reduced. In the R1 randomisation, patients will be randomised to receiving the Delayed Intensification (DI) phase of therapy with or without the anthracycline Doxorubicin.

A similar hypothesis of over-treatment will also be tested in patients stratified to the intermediate risk-low group. In the R2 randomisation patients will be randomly assigned to either removal of Doxorubicin during the DI phase or removal of Vincristine and Dexamethasone pulses during the maintenance phase or to the control group, which will be treated with Doxorubicin in DI as well as Vincristine and Dexamethasone pulses during maintenance. Patients will only be randomised once.