Conquering Diffuse Large B-Cell Lymphoma with Bioocus Dual CAR-T Therapy

Patient Background

Rodney, a resilient individual from abroad, was diagnosed with Diffuse Large B-Cell Lymphoma (DLBCL), an aggressive form of non-Hodgkin lymphoma. At 68 years old, he sought advanced treatment options after conventional therapies proved insufficient. Referred to our partner facility at Tianjin Cancer Hospital, Rodney enrolled in Bioocus's dual CAR-T therapy protocol under treatment number P1549. This therapy targets both CD19 and CD20 antigens on cancer cells, offering a dual-pronged attack to enhance efficacy and reduce the risk of relapse.

The Treatment Journey

Rodney's treatment began in September 2025 with the infusion of autologous CAR-T cells engineered to express chimeric antigen receptors for CD19 and CD20. The process involved collecting his peripheral blood (PB) sample, processing it to create personalized CAR-T cells, and infusing a dose tailored to his needs. Post-infusion, his progress was closely monitored through serial blood tests on key tracking days: Day 4 (D4), Day 7 (D7), and Day 10 (D10).

• D4 (September 12, 2025):Initial detection showed modest CAR-T cell presence, with CD19+ CAR-T cells at 0.50% of CD3+ T cells (absolute value: 6.04 × 10^6/L) and CD20+ CAR-T cells at 0.41% (absolute value: 4.96 × 10^6/L). This early phase indicated successful engraftment.
• D7 (September 15, 2025):Expansion accelerated, with CD19+ CAR-T cells rising to 1.68% (absolute value: 1.40 × 10^7/L) and CD20+ CAR-T cells to 1.63% (absolute value: 1.36 × 10^7/L), demonstrating robust proliferation.
• D10 (September 18, 2025):Remarkable peak expansion was observed, with CD19+ CAR-T cells reaching 31.43% of CD3+ T cells (absolute value: 3.13 × 10^8/L) and CD20+ CAR-T cells at 32.74% (absolute value: 3.26 × 10^8/L). Subset analysis revealed balanced distribution across CD4+ and CD8+ T cells, with overall T-cell counts at 2.9 × 10^9/L, including 34.35% CD3+ T cells.

Throughout the monitoring, Rodney's immune profile showed positive shifts, such as elevated cytotoxic T cells (CD3+CD8+ at 69.56%), underscoring the therapy's ability to mobilize his immune system against the lymphoma.

Outstanding Outcomes

By D10, the explosive growth in CAR-T cells—over a 500-fold increase in absolute counts from D4—highlighted the therapy's potent anti-tumor activity. This rapid expansion is a hallmark of successful CAR-T treatment, often correlating with deep and durable remissions in DLBCL patients. Rodney tolerated the therapy well, with no major complications reported in the monitoring phase. His case exemplifies Bioocus's dual CAR-T approach, which has achieved high complete response (CR) and overall response rates (ORR) across our global patient cohort.