International Journal Publication | Dr. Xiaoyan KE and Dr. Kai HU's Team: BCMA CAR-T Brings Short-Term Remission and Survival Benefit in R/R PCL

Summary: Relapsed/refractory primary plasma cell leukemia (R/R PCL) is rare, highly aggressive, and associated with poor outcomes after conventional treatment. A retrospective cohort study from the teams of Dr. Xiaoyan KE and Dr. Kai HU at Beijing GoBroad Hospital analyzed outcomes in 12 patients with triple-class refractory R/R PCL treated with BCMA CAR-T therapy. The overall response rate was 75%, with a median progression-free survival of 8.9 months and a median overall survival of 15.5 months. Among patients who subsequently underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) as consolidation, some achieved deep remission and long-term disease-free survival. The findings provide early evidence for a potential treatment strategy in this very high-risk patient population.

Relapsed/refractory primary plasma cell leukemia (R/R PCL) is a rare but highly aggressive hematologic malignancy. Response rates with conventional treatment are low, and long-term outcomes remain poor, making it one of the most challenging conditions managed by lymphoma and myeloma specialists. In recent years, CAR-T cell therapy targeting B-cell maturation antigen (BCMA) has shown activity in R/R PCL, but data on long-term outcomes and the best treatment strategy after CAR-T remain limited.

Recently, the lymphoma and myeloma team at Beijing GoBroad Hospital, led by Dr. Xiaoyan KE and Dr. Kai HU, published a study in Frontiers in Immunology titled "Efficacy of BCMA CAR-T cell therapy and subsequent strategies in refractory and relapsed plasma cell leukemia: a retrospective cohort study." The first author was Dr. Yuelu GUO. The study summarizes the team's recent clinical experience with BCMA CAR-T in R/R PCL and explores possible strategies after CAR-T treatment.

Study Background

Dr. Kai HU noted that primary plasma cell leukemia (PCL), although rare, is highly aggressive. Even with newer therapies, newly diagnosed PCL has been reported to have a median progression-free survival (PFS) of only 5.5 months. Outcomes become especially poor after relapse, particularly in patients with triple-class refractory disease - meaning resistance to proteasome inhibitors, immunomodulatory drugs, and anti-CD38 monoclonal antibodies. To further evaluate the efficacy and safety of BCMA CAR-T in R/R PCL, the team retrospectively analyzed 12 patients with triple-class refractory R/R PCL who received BCMA CAR-T therapy.

Key Findings

1. BCMA CAR-T Achieved a 75% Response Rate in Triple-Class Refractory PCL, with Mostly Low-Grade CRS

The overall response rate (ORR) after BCMA CAR-T therapy was 75% (9/12). One patient achieved complete response (CR), four achieved partial response (PR), and four achieved very good partial response (VGPR). Grade 1-2 cytokine release syndrome (CRS) occurred in 83.3% of patients (10/12). At the same time, grade 3-4 cytopenias were common, highlighting the need for careful infection prevention, monitoring, and supportive care after BCMA CAR-T therapy in patients with R/R PCL.

2. BCMA CAR-T Provided Survival Benefit in R/R PCL, with Encouraging Outcomes in Patients Who Bridged to Allogeneic Transplant

Further analysis showed a median PFS of 8.9 months (95% CI, 4.6 months to not reached). The 1-year and 2-year PFS rates were 33.3% (95% CI, 7.8%-62.3%) and 22.2% (95% CI, 3.4%-51.3%), respectively. Median overall survival (OS) was 15.5 months (95% CI, 5.7 months to not reached). The 1-year OS rate was 55.6% (95% CI, 20.4%-80.5%), and the 2-year OS rate was 22.2% (95% CI, 3.4%-51.3%). Notably, among the four patients who underwent allogeneic transplantation as consolidation, two remained in stringent complete response (sCR) and achieved disease-free survival.

These preliminary findings may help inform treatment planning. For patients with R/R PCL who respond to BCMA CAR-T therapy, consolidation with allogeneic hematopoietic stem cell transplantation may deepen the response and could support longer disease-free survival in selected patients. Larger prospective studies are still needed to clarify which patients are most likely to benefit.

Summary and Outlook

Dr. Xiaoyan KE noted that the Department of Lymphoma and Myeloma at Beijing GoBroad Hospital has accumulated extensive clinical experience with CAR-T therapy. As more patients receive CAR-T in real-world practice, the clinical questions are becoming increasingly complex. Current experience suggests that BCMA CAR-T can produce short-term remission in highly aggressive R/R PCL, but additional consolidation may be needed to improve the depth and durability of response. Allogeneic hematopoietic stem cell transplantation may be one strategy for selected patients who respond to CAR-T. At the same time, identifying the right timing for CAR-T and developing more individualized, precise, and longitudinal management strategies remain important clinical priorities. Going forward, integrated clinical, pathologic, molecular, and imaging assessment may help identify R/R PCL patients who are unlikely to benefit from conventional therapy but may benefit from precision CAR-T approaches. Monitoring tools such as circulating tumor DNA (ctDNA) may also help detect signs of relapse earlier and support more timely intervention.