Testing the safety and effectiveness of loncastuximab tesirine for the treatment of relapsed/refractory B-cell non-hodgkin lymphoma

This study aimed to evaluate the safety and effectiveness of loncastuximab tesirine (LoT; Lonca) for the treatment of patients with relapsed/refractory (R/R) B-cell non-Hodgkin lymphoma (B-NHL). The study found that LoT was safe and had promising activity in these patients. 

B-NHL is a type of blood cancer. There are different types of B-NHL including diffuse large B-cell lymphoma (DLBCL) which is aggressive and follicular lymphoma (FL) which is less aggressive. A high number of patients with B-NHL experience relapse (worsening of the disease) or refractory (not responsive to the treatment) disease. Patients with RR disease have limited treatment options.

LoT is a new form of therapy. It is an antibody-drug conjugate (ADC). ADCs include an immune-targeting marker that is found in high amounts in the tumor and a toxin that is good at breaking down tumor cells. The immune marker carries the toxin to the tumor where it can kill the tumor cells.

The effectiveness of LoT in patients with B-NHL and which dose patients should be given without serious side effects is currently unknown.

This study included 183 patients with B-NHL in a phase 1 clinical trial. Patients were given increasing doses of LoT. The average follow-up time was 5.4 months.

98.9% of patients reported mild side effects such as fatigue. 46.4% of patients had at least 1 serious side effect. These included low white blood cell count with fever, fever, and liquid buildup around the lungs. The highest dose of LoT which had the least side effects was 150 µg/kg. This dose was chosen to move forward with testing.

45.6% of all patients responded to treatment. Different types of NHL responded differently to LoT. 42.3% of patients with DLBCL, 46.7% of those with mantle cell lymphoma (MCL), and 78.6% of those with FL responded to LoT. The response lasted 5.4 months on average. Response to LoT was seen in patients aged 75 years or older and in aggressive NHL types such as double- or triple-hit lymphoma.

This study showed that LoT was safe and had a promising anti-tumor activity for patients with B-NHL. 

This was a small phase I study. Further testing is needed to establish how effective LoT is at treating B-NHL.