The following is a summary of “Association between treatment (tx) response and PFS and OS in R/R chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL): A 12-month landmark (LM) meta-analysis,” published in the 2024 ASCO Annual Meeting under issue of Oncology by Woyach et al.

With advancements in treatment methods for chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL), complete remissions (CR) are not observed regularly in relapsed/refractory (R/R) settings, which further affects long-term results.  

Researchers conducted a retrospective study to understand the correlation between treatment response and survival in patients with R/R CLL/SLL. 

They studied adults, sourced from the Medidata Enterprise Data Store, with R/R CLL/SLL who had at least one prior line of therapy (LOT) from six clinical trials conducted between 2012 and 2022. Cox models were used to analyze links between achieving CR or CR with incomplete bone marrow recovery (CR/CRi) within 12 months and progression-free and overall survival outcomes (PFS/OS). In separate landmark (LM) analyses (LMA), partial responses (PR) and non-responses (nPR) or non-CR/ non-PR were assessed. 

The results showed that out of 1,604 patients (CLL 97.7%, SLL 2.3%, 61.8% patients aged ≥ 65, 66.6% male, ECOG PS 0-1/2, 93.2%/6.8%, median follow-up, 3.4 y [2.2-4.1]; median LOT, 2 [1-3]; study treatment, BTKi [40.4%], BCL2i [40.1%], anti-CD20 mAb [12.5%], and PI3Ki [9.9%]). 15.1% achieved CR/CRi, and 61.7% achieved PR/nPR (ORR 76.8%), with 6.8% of patients having no recorded response in follow-up. Median PFS from LM: CR/CRi 64.4 months (61.7- not reached [NR]), PR/nPR 43.3 (38.8-54.7) months, non-CR/non-PR 23.9 (18.3-50.6) months. Patients who achieved and maintained CR/CRi had longer PFS, with aHR of 0.62 (P=0.01) and 0.64 (P=0.02). For OS in LMA, 1,404 patients were included. Median OS: CR/CRi and PR/nPR were not reached, and non-CR/non-PR was 62.9 (51.2-NR) months. At 24 mo from LM, 90% (85%–95%) CR/CRi, 87% (84%–89%) PR/nPR, and 72% (67%–77%) non-CR/non-PR pts were still alive. Patients with CR/CRi had significantly longer PFS and OS.

Investigators concluded that achieving and maintaining CR/CRi within 12 months led to better PFS than PR/nPR or no response, highlighting the value of durable CR/CRi as an early endpoint for treatment evaluation in R/R CLL/SLL.

Source: meetings.asco.org/abstracts-presentations/238957