Evaluating haploidentical stem cell transplantation for advanced lymphoma

This study looked at the effect of a gentler stem cell transplant (SCT) from a partially matched donor for patients with advanced lymphoma. It found that haploidentical SCT is an effective treatment option for these patients.

Lymphomas are a group of cancers of white blood cells within the lymph nodes. Common types include Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL). Lymphomas are typically treated with chemotherapy, and targeted treatments are also common. 

If the cancer relapses (returns) after initial treatment, SCT is an option. SCT involves injecting stem cells, which replace the lymphoma cells killed after chemotherapy. SCT can be done using stem cells isolated from the patient’s own blood. For patients unsuccessful using their own stem cells, SCT using a donor is an effective treatment.

HLA genes regulate the immune system and are part of how white blood cells recognize other cells of the body. There are multiple versions (alleles) of each of the HLA genes. The best SCT donors have exactly the same HLA genes as the patient. However, for some patients, it is difficult to find an exact match. Haploidentical SCT (haplo-SCT) uses a donor who matches exactly half of the HLA genes and is typically a close family member. It is not clear what the outcomes of this treatment are in patients with advanced lymphoma.

This study used records from 147 patients with lymphoma that had relapsed after chemotherapy. All patients underwent haplo-SCT. They received pretreatment with chemotherapy to reduce the amount of cancer before the SCT. However, they did not receive the strong doses needed to eliminate all lymphoma. The average follow-up period was 39 months.

By 100 days after the transfer, 95% of patients had only white blood cells derived from the donor. The haplo-SCT was unsuccessful for 5% of patients.

Two years after the haplo-SCT, 66% of the patients were alive without the lymphoma progressing (worsening) and 72% of patients were alive. Overall, 19% of patients relapsed after 2 years. Relapse was more common in patients who still had signs of lymphoma at the time of SCT.

Graft versus host disease (GVHD) occurs when transplanted T-cells (immune cells) attack the body of the patients. Following the SCT, all patients received cyclophosphamide (Cytoxan) to remove T-cells and reduce the risk of GVHD. 30% of patients experienced symptoms of GVHD, which can include rash, nausea, and diarrhea. 3% of patients had severe GVHD. Other side effects included infection from bacteria (47%) or viruses (21%).

This study found that haplo-SCT is an effective treatment for relapsed advanced lymphoma.

This study did not compare haplo-SCT to other treatment options, such as chimeric antigen receptor T-cell (CART) therapy. Also, this study used medical records data. Information may have been incomplete. Further studies are needed on the effectiveness of this treatment.