Adult patients with acute lymphoblastic leukaemia (ALL)  can achieve disease control in 90% of cases with intense chemotherapy but only half of these responders will be cured.

For patients who are either refractory or relapse after chemotherapy the outcome is dismal despite undergoing more chemotherapy and/or an allogeneic haematopoetic stem cell transplantation.

Immunotherapy offers a new treatment option.

This can be delivered by the bispecifc antibody construct blinatumomab, which can engage with patients own T cells to fight ALL cells.

A single arm Phase II trials with blinatumomab has shown that 43% of relapsed or refractory (r/r) ALL patients can achieve disease control.

The aim of Tower trial was to answer the question if blinatumomab can achieve a survival benefit in adult patients with r/r acute lymphoblastic leukaemia compared to standard chemotherapy (SOC).

More than 400 r/r ALL patients in Europe, North America, Asia and Australia were randomised 2:1 to receive either blinatumomab or SOC.

The trial was stopped prematurely as blinatumomab demonstrated almost doubling of the overall survival when compared to chemotherapy.

This benefit was seen in all subgroup of patients including patients who relapsed after an allogeneic haematopoetic stem cell transplantation and/or who have received multiple different chemotherapy regiments.

Blinatumomab treatment did not result in more serious side effects than chemotherapy.

In conclusion blinatumomab is the first immunotherapy agent that has proven to extend patients life with relapsed acute lymphoblastic leukaemia when compared to chemotherapy.

Source: EHA