Allogeneic stem cell transplant in patients with classic Hodgkin lymphoma who have been treated with immune checkpoint inhibitors

This study aimed to investigate the safety and effectiveness of allogeneic stem cell transplantation (alloSCT) after immune checkpoint inhibitor (ICI) treatment in patients with classic Hodgkin lymphoma (cHL).  

This study concluded that this treatment is safe and has very good outcomes in these patients.  

Immune checkpoint inhibitors (ICIs) are an approved treatment for relapsed classic Hodgkin lymphoma (cHL). ICIs are a type of immunotherapy. They work by blocking proteins on cancer cells that inactivate the immune system. Therefore, ICIs help the immune system detect and attack cancer cells.

Allogeneic blood or bone marrow transplantation (alloBMT) is another treatment for cHL. During alloBMTstem cells from a donor are transplanted to the patient to replace cells damaged during cancer treatment and to boost the immune system. After transplantation, chemotherapy drug cyclophosphamide (Cytoxan) is used to prevent graft-versus-host-disease (GVHD). GVHD is when the transplanted cells attack the patient.

AlloBMT is commonly done after chemotherapy to kill cancer cells. However, the safety and effectiveness of alloBMT after ICI treatment in patients with cHL were unknown.

This study involved 105 patients with relapsed cHL. 35.2% of patients received ICIs and 64.7% received chemotherapy without ICIs. All patients received alloBMT using cyclophosphamide (Cy) GVHD prevention treatment. The average follow-up period was 15 months in the ICI group and 53 months in the no-ICI group. 

The 3-year overall survival for ICI patients was 94% compared to 78% for the non-ICI patients. ICI treatment before alloBMT was associated with a 65% higher chance of survival compared to chemotherapy.  

The 3-year survival rate without cancer worsening for ICI patients was 90% compared to 65% for the non-ICI patients. ICI treatment was associated with a 70% higher chance of surviving without cancer worsening. 

There was a slightly higher rate of short-term GVHD in the ICI group at 12 months (33%) compared to the no-ICI group (17%). There was a slightly lower occurrence of long-term GVHD at 24 months in the ICI group (3%) compared to the no-ICI group (14%).  

This study concluded that ICI treatment is safe and effective before alloBMT in patients with relapsed cHL.

This study was based on medical records. Information might have been incomplete. Also, the follow-up period was shorter in the ICI group. Further studies are needed.