Comparing chemotherapy dosing approaches for patients with non-Hodgkin lymphoma before a stem cell transplant

This study evaluated two different dosing approaches for busulfan (Busilvex) chemotherapy for patients with non-Hodgkin lymphoma (NHL) before an autologous stem cell transplant (SCT). The authors found that personalizing treatment dose for these patients was more effective than conventional weight-based dosing.

Autologous SCT is a standard treatment option for patients with NHL. High-dose chemotherapy called a conditioning regimen is given first to get rid of any remaining cancer cells. Busulfan is one of the most common chemotherapy drugs used for conditioning regimens. Different factors are involved in determining the best dose of busulfan for a patient.

Weight-based dosing (WBD) bases the treatment dose on a patient’s body weight. However, measuring doses this way is often inaccurate, leading to a too-low dose or a too-high dose. Customizing treatment dose in real-time to ensure that enough medicine is in the patient’s blood may be a more effective approach. This is called therapeutic drug monitoring (TDM). Whether TDM is more effective than WBD for patients with NHL is unclear.

This study had 336 adult patients with NHL who underwent autoSCT. 258 patients received conditioning with WBD before the transplant. 78 patients received conditioning with TDM before the transplant. The conditioning regimen included busulfan, etoposide (Toposar), and cyclophosphamide (Cytoxan). Patients were followed for an average of 24 to 81 months.

Before the transplant, 51% of all patients had no signs of cancer (complete remission). Significantly more patients in the TDM group were in remission compared to patients in the WBD group (67.9% vs. 45.7%).

Two years later, significantly more patients in the TDM group were still alive without tumor growth or spread compared to the WBD group (69% vs. 55%). Overall survival (number of patients still alive 2 years later) was similar between the two groups (70% vs. 71%).

Significantly fewer patients in the TDM group had the cancer come back (relapse) compared to the WBD group (19% vs. 38%). TDM was significantly associated with a 48% lower risk of relapse.

The authors found that personalizing treatment doses for patients with NHL led to better outcomes after autologous SCT compared to conventional weight-based dosing.

This study was retrospective, meaning it looked back in time to analyze data. Also, the WBD group had more patients compared to the TDM group. This may bias the results. More studies are needed to confirm the effectiveness of TDM.