Patients with acute lymphocytic leukaemia (ALL) who are in remission may have trace amounts of residual disease in their bone marrow, which is known to increase the risk of suffering a relapse.

This study pairs new and evolving methods to detect minimal residual disease (MRD) with a new antibody that recruits T cells to attack lingering disease cells.

Blinatumomab, an investigational drug known as a bispecific T cell Engager (BiTE©) antibody construct, is designed to bind to a protein on the surface of ALL cells (CD19) as well as to a protein on the surface of T cells (CD3), uniting the cells and charging the T cell to attack the cancer cell.

As the T cells continue to attack, they detach from cells they have destroyed and proliferate, attaching to new prey.

To evaluate the efficacy and safety of blinatumomab in patients with detectable minimal residual disease, investigators enrolled 116 adults with ALL in a Phase II trial.

Patients received continuous infusion of the treatment for four weeks followed by a two-week, treatment-free period; responders could receive up to four cycles of treatment or undergo stem cell transplant after one cycle. Of 113 patients enrolled in the trial and evaluable for assessment of minimal residual disease, 88 (78%) experienced a complete MRD response (no minimal residual disease detected).

Nearly all complete responses (98%) occurred within the first treatment cycle.

Most treatment-related toxicity (e.g., headache, fever, and fatigue) was related to cytokine release, which develops as a result of successful T cell activation and expansion.

Other patients experienced neurologic events; however, none of these events were fatal.

One patient died from atypical pneumonia that was considered to be related to treatment.

“This is one of the first studies to evaluate a new compound in patients when they have trace amounts of residual disease, rather than when they are experiencing a full relapse,” said lead study author Nicola Gökbuget, MD, of Goethe University in Frankfurt, Germany.

“Our results with blinatumomab demonstrate the significant clinical activity of this compound in ALL. Further follow up will be necessary to demonstrate that starting similar treatments when patients have a lower disease level may provide more long-term benefit.”

Watch the press conference and the interview for more.

Source: ASH