What type of stem cell transplant is most effective after early treatment failure in follicular lymphoma?

This study investigated the effectiveness of stem cell transplantation in follicular lymphoma patients who experienced early treatment failure after frontline chemoimmunotherapy. This study concluded that transplants using the patient's own stem cells or those from a matched sibling donor lead to better survival outcomes in these patients.

Chemoimmunotherapy regimens involving rituximab (Rituxan) remains the standard of care for follicular lymphoma. However, many patients experience relapse soon after treatment (early treatment failure). Patients with early treatment failure tend to have worse outcomes than patients who relapse later.

Stem cell transplantation (HCT) may be an effective option for these higher-risk patients. This involves replacing the patient’s cancer cells with healthy stem cells from a donor (alloHCT) or the patient (autoHCT). In alloHCT, the donor may be related to the patient (a matched sibling donor), or an unrelated matched donor. Whether autoHCT or alloHCT would offer the most benefit for high-risk follicular lymphoma patients with early treatment failure remains under unclear.

This study compared the outcomes of different types of transplantation in 444 patients.. 82.5% of all patients had stage 3 – 4 disease. Patients underwent either autoHCT (54.5%) or alloHCT (45.5%) as their first stem cell transplant. Of those who had alloHCT, 52.5% had a matched sibling donor (sibling) and 47.5% had a matched unrelated donor (unrelated).

Before HCT, 36% (autoHCT), 24% (sibling), and 20% (unrelated) of patients were in remission. The average follow-up periods were 69 to 73 months.

There were no differences in rates of graft-versus-host disease 100 days after transplant in the sibling (35%) or unrelated (35%) groups. Graft-versus-host disease is a complication in which the transplanted cells attack healthy cells.

At 5 years, the probability of non-relapse mortality (death not due to relapse or progression) was significantly lower in the autoHCT group (5%), compared to the sibling group (17%) and unrelated group (33%). The probability of survival after 5 years was significantly higher in the autoHCT group (70%) and sibling group (73%) compared to the unrelated group (49%).

At 5 years, the probability of relapse or disease progression was significantly higher in the autoHCT group (58%) compared to the sibling group (31%) and unrelated group (23%). 12% of autoHCT patients relapsed and underwent alloHCT.

This study concluded that stem cell transplantation is an effective treatment for patients with early treatment failure, particularly autoHCT and sibling alloHCT.

This study was observational, and collected data from a large patient registry. This may limit the conclusions that can be drawn from these results.