Is autologous stem cell transplantation after anti-PD-1 therapy an effective treatment for patients with relapsed or refractory Hodgkin lymphoma?

The authors assessed the effectiveness of autologous stem cell transplantation (ASCT) after anti-PD-1 therapy for the treatment of patients with high-risk relapsed/refractory (r/r) Hodgkin lymphoma (HL).

The study found that ASCT after anti-PD-1 therapy had very good outcomes in patients with r/r HL.

Standard treatments for r/r HL include chemotherapy combined with ASCT. ASCT uses healthy blood stem cells from the patient's own body to replace cancerous cells destroyed by chemotherapy. The standard treatment has improved r/r HL patient outcomes. However, a high number of patients with HL experience relapse (worsening of disease) or refractory (not responsive) disease to standard treatments.

Immune checkpoint inhibitors (ICI) such as anti-PD-1 therapy are a type of immunotherapy. ICIs prevent the immune system from switching off. This allows the immune system to target and kill cancer cells. Anti-PD-1 therapies are known to be effective at reducing tumor size. However, the majority of patients who are treated with anti-PD-1 therapies eventually relapse.

In a small study, anti-PD-1 therapy has proven to make patients with r/r HL sensitive again to chemotherapy. However, more data regarding the effectiveness of ASCT after anti-PD-1 therapy in patients with r/r HL is needed.   

This study enrolled 78 patients with high-risk r/r HL. Patients had ASCT after getting an anti-PD-1 drug (alone or in combination). 74% of patients had ASCT after anti-PD-1 treatment, while 26% of patients had additional therapy after anti-PD-1 treatment and before ASCT. Before anti-PD-1 therapy patients had received an average of 3 previous therapies. After ASCT, patients were followed up for an average of 19.6 months.

81% of patients were alive without cancer worsening after 18-months. Overall, 96% of patients were alive after 18 months. These outcomes were true even for patients who previously were resistant to 3 standard therapies. 

The authors concluded that ASCT after anti-PD-1 therapy was an effective treatment for patients with high-risk r/r HL.

Many research centers took part in this study. The treatment approach may have differed across all the centers.