Evaluating the FMT regimen before a stem cell transplant in patients with aggressive non-Hodgkin lymphoma

This study evaluated the effectiveness of the FMT (fludarabine, melphalan, total body irradiation) regimen in patients with non-Hodgkin’s lymphoma (NHL) that has come back or stopped responding to treatment. This study concluded that this regimen was well-tolerated and effective.

Many patients with aggressive NHL experience relapse (cancer recurrence) after initial treatment. Some patients also develop tumors that no longer respond to treatment (refractory). Salvage therapy may help eliminate remaining cancer or induce a response in refractory disease. One common salvage therapy is an allogeneic stem cell transplant (alloSCT).

AlloSCT involves collecting healthy stem cells from a donor. Then, these healthy stem cells are introduced into the patient. A conditioning regimen is given first to get rid of any remaining cancer cells. This regimen can be chemotherapy alone, or chemotherapy combined with radiation therapy. How well the FMT regimen works in patients with relapsed or unresponsive NHL before they undergo alloSCT is under investigation.

This study had 89 patients with aggressive NHL that has come back or stopped responding to treatment. Patients were treated with the FMT regimen before undergoing alloSCT. Patients were followed-up for an average of 41 months.

At follow-up, 46.1% of patients had no signs of lymphoma. 47.1% of patients were still alive 3 years later. 45.4% of patients were still alive without tumor growth or spread.

On average, 33.7% of patients had tumor growth or spread at an average of 7.2 months after alloSCT. 1 year later, this rate was 20.5%. 3 years later, this rate was 33.1%.

Overall, 33.7% of all patients developed short-term graft-versus-host disease (GVHD). This is a condition where the donated stem cells attack the patient’s healthy cells. 1 year later, this rate was 34.2%. 52.8% of all patients developed long-lasting GVHD. 3 years later, this rate was 27.0%. Most cases of GVHD were mild.

Most side effects associated with the FMT regimen were mild. The most common included sore mouth or gums (21.3%). 15.7% of patients also had nausea.

Having refractory disease before alloSCT was significantly associated with a 2.45-fold higher mortality risk. Refractory disease was also significantly associated with a 2.33-fold higher risk of tumor growth or spread. Developing severe GVHD was associated with a 7.98-fold higher mortality risk.

This study concluded that the FMT regimen was well-tolerated and effective in patients with recurring or non-responsive NHL before alloSCT.

This study was retrospective. This means it looked back in time to analyze data. This may limit the conclusions that may be drawn from these results. More studies are needed to confirm these results.