Real-World Characteristics and Outcome of Patients Treated With Single-Agent Ibrutinib for Chronic Lymphocytic Leukemia in Spain (IBRORS-LLC Study)

BACKGROUND

Ibrutinib demonstrated remarkable efficacy and favorable tolerability in patients with untreated or relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL), including those with high-risk genetic alterations. The IBRORS-CLL study assessed the characteristics, clinical management and outcome of CLL patients receiving ibrutinib in routine clinical practice in Spain.

PATIENTS

Observational, retrospective, multicenter study in CLL patients who started single-agent ibrutinib as first-line treatment or at first or second relapse between January 2016 and January 2019.

RESULTS

A total of 269 patients were included (median age: 70.9 years; cardiovascular comorbidity: 55.4%, including hypertension [47.6%] and atrial fibrillation [AF] [7.1%]). Overall, 96.7% and 69% of patients underwent molecular testing for del(17p)/TP53 mutation and IGHV mutation status. High-risk genetic features included unmutated IGHV (79%) and del(17p)/TP53 mutation (first-line: 66.3%; second-line: 23.1%). Overall, 84 (31.2%) patients received ibrutinib as first-line treatment, and it was used as second- and third-line therapy in 121 (45.0%) and 64 (23.8%) patients. The median progression-free survival and overall survival were not reached irrespective of del(17p)/TP53, or unmutated IGHV. Common grade ≥3 adverse events were infections (12.2%) and bleeding (3%). Grade ≥3 AF occurred in 1.5% of patients.

CONCLUSION

This real-world study shows that single-agent ibrutinib is an effective therapy for CLL, regardless of age and high-risk molecular features, consistent with clinical trials. Additionally, single-agent ibrutinib was well tolerated, with a low rate of cardiovascular events. This study also emphasized a high molecular testing rate of del(17p)/TP53 mutation and IGHV mutation status in clinical practice according to guideline recommendations.

Clinical impact of the subclonal architecture and mutational complexity in chronic lymphocytic leukemia

Genome studies of chronic lymphocytic leukemia (CLL) have revealed the remarkable subclonal heterogeneity of the tumors, but the clinical implications of this phenomenon are not well known. We assessed the mutational status of 28 CLL driver genes by deep-targeted next-generation sequencing and copy number alterations (CNA) in 406 previously untreated patients and 48 sequential samples. We detected small subclonal mutations (0.6-25% of cells) in nearly all genes (26/28), and they were the sole alteration in 22% of the mutated cases. CNA tended to be acquired early in the evolution of the disease and remained stable, whereas the mutational heterogeneity increased in a subset of tumors. The prognostic impact of different genes was related to the size of the mutated clone. Combining mutations and CNA, we observed that the accumulation of driver alterations (mutational complexity) gradually shortened the time to first treatment independently of the clonal architecture, IGHV status and Binet stage. Conversely, the overall survival was associated with the increasing subclonal diversity of the tumors but it was related to the age of patients, IGHV and TP53 status of the tumors. In conclusion, our study reveals that both the mutational complexity and subclonal diversity influence the evolution of CLL.

Update of the Grupo Español de Leucemia Linfocítica Crónica clinical guidelines of the management of chronic lymphocytic leukemia

BACKGROUND AND OBJECTIVE

The broad therapeutic arsenal and the biological heterogeneity of patients with chronic lymphocytic leukemia (CLL) makes it difficult to standardize treatment for CLL patients with specific clinical settings in routine clinical practice. These considerations prompted us to elaborate the present consensus document, which constitutes an update of the previous version published in 2013, mainly focusing on novel treatment strategies that have been developed over last 5 years, namely B-cell receptor inhibitors (ibrutinib and idelalisib), anti-CD20 monoclonal antibodies (ofatumumab and obinutuzumab), and Bcl-2 inhibitors (venetoclax).

MATERIAL AND METHODS

A group of experts from the Spanish Chronic Lymphocytic Leukemia Group reviewed all published literature from January 2010 to January 2016, in order to provide recommendations based on clinical evidence. For those areas without strong scientific evidence, the panel of experts established consensus criteria based on their clinical experience.

RESULTS

The project has resulted in several practical recommendations that will facilitate the diagnosis, treatment, and follow-up of patients with CLL.

CONCLUSIONS

There are many controversial issues in the management of CLL with no appropriate studies for making consensus recommendations.