Does combining brentuximab vedotin with chemotherapy reduce the risk of consolidative radiotherapy for patients with early-stage unfavorable-risk Hodgkin lymphoma?

This study investigated whether brentuximab vedotin (Adcedris; BC) + AVD (doxorubicin, vinblastine, and dacarbazine) chemotherapy combination resulted in a reduction or elimination of consolidative radiotherapy in early-stage unfavorable-risk Hodgkin lymphoma (HL). The data showed that the BV+AVD combination with and without consolidative RT was associated with excellent effectiveness and survival outcomes.

Chemotherapy and consolidative RT is the standard of care for patients with early-stage unfavorable-risk HL. Consolidative radiotherapy (RT) is meant to kill any cancer cells left after initial treatment. However, RT can have serious side effects such as developing secondary cancers, decreased thyroid function, or heart disease.

Positron emission tomography (PET) scanning during treatment may be able to help identify low-risk patients who respond to chemotherapy and do not need RT. In patients with newly diagnosed early-stage unfavorable-risk HL, PET4-negativity (no signs of cancer) after 4 cycles of chemotherapy could safely omit consolidative RT.

BV + AVD chemotherapy combination was shown to be more effective and safer over the long term in patients with advanced HL. Whether treatment with BV + AVD might reduce or eliminate consolidative RT in patients with early-stage unfavorable-risk HL is not known.

This study involved 117 patients with early-stage unfavorable-risk HL. All patients were given BV+AVD chemotherapy for 4 cycles. Patients were then divided into 4 groups. Group 1 included 30 patients who received 30 Gy of involved-site RT (ISRT; RT delivered to HL-affected areas). Group 2 included 29 patients who received 20 Gy of ISRT. Group 3 included 29 patients who received 30 Gy of consolidative RT (RT was delivered only to the areas where tumors were larger than 1.5 cm). Group 4 included 29 patients who did not receive any RT. The average follow-up time was 3.8 years.

The complete response rate was 93% in group 1, 100% in group 2, 93% in group 3, and 97% in group 4. Overall, 99% of patients were alive after 2 years. 94% of patients were alive without any worsening of the cancer after 2 years. 

After 2 years, 93.1% of patients in group 1, 96.6% in group 2, 89.7% in group 3, and 96.6% in group 4 were alive without cancer worsening.

44% of the patients had a low white blood cell count. 54% of patients had neuropathy (numbness or tingling in the limbs, hands, or feet). However, most of these were mild and resolved during the study.

This study concluded that BV+AVD was a highly effective and well-tolerated treatment regimen for patients with early-stage unfavorable-risk HL and allowed for a reduction or omission of consolidation RT. 

The number of patients in each group was very small. Patients were not randomly assigned to the groups. This might affect the conclusions.