Final CLL14 Analysis Confirms Durable Benefit With Fixed-Duration Venetoclax-Obinutuzumab in Frontline CLL

Final results from the phase 3 CLL14 trial (NCT02242942) presented at the 2026 European Hematology Association Congress provide nearly a decade of follow-up data supporting the long-term efficacy of fixed-duration venetoclax (Venclexta; AbbVie Inc) plus obinutuzumab (Gazyva; Genentech, Inc) (Ven-Obi) for patients with previously untreated chronic lymphocytic leukemia (CLL) and coexisting medical conditions.¹

"The final results of CLL14 confirm the long-term efficacy of 1-year fixed-duration Ven-Obi in previously untreated patients with CLL and coexisting conditions," the investigators reported.¹

CLL and Ven-Obi

CLL is the most common leukemia, accounting for 1 in 3 leukemia diagnoses.² According to the American Cancer Society, there will be an estimated 22,760 new cases of CLL (13,810 in men and 8950 in women) and about 4350 deaths from CLL (2720 in men and 1630 in women) in the United States in 2026 alone.² CLL is associated with favorable long-term survival outcomes, with overall survival (OS) rates of approximately 90% at 5 years and 86% at 10 years due to improved therapeutic options.³

The standard frontline treatment for patients with CLL is 1 year of Ven-Obi, which was supported by data from the CLL14 trial.¹ Venetoclax is a highly selective BCL2 inhibitor that is approved for the treatment of relapsed or refractory CLL and acute myeloid leukemia.⁴ BCL2 is an antiapoptotic protein that is highly overexpressed in CLL cells, allowing malignant cells to evade programmed cell death.⁵ Venetoclax is designed to copy the actions of the physiological antagonists of BCL2 and bind directly to the protein to reinstate apoptosis.⁴ When combined, venetoclax and obinutuzumab—a CD20-targeting monoclonal antibody—help restore programmed cell death in malignant cells and promote their elimination through immune-mediated mechanisms and direct cell death.⁶

Final Results From CLL14

The phase 3 CLL14 trial helped establish 1 year of Ven-Obi as a standard frontline treatment option, demonstrating durable remissions and prolonged treatment-free intervals with a median follow-up of 110.1 months (about 9 years).¹

A total of 432 patients were randomly assigned to receive either Ven-Obi (n = 216) or chlorambucil plus obinutuzumab (Clb-Obi; n = 216). At the time of analysis, all patients had been off study treatment for at least 8 years.¹

Ven-Obi continued to demonstrate a significant progression-free survival (PFS) advantage over Clb-Obi. Median PFS was approximately 76.6 months with Ven-Obi compared with 37.9 months in the comparator arm (HR, 0.50; 95% CI, 0.39-0.63; P < .001). Progressive disease occurred in 87 patients receiving Ven-Obi vs 144 patients receiving Clb-Obi.¹

The benefit extended to time to next treatment (TTNT), which approached 8 years in the Ven-Obi arm. Median TTNT with Ven-Obi was 91.9 months compared with 52.5 months for Clb-Obi (HR, 0.54; 95% CI, 0.43-0.70; P < .001). Notably, only 54 patients in the Ven-Obi group required second-line therapy compared with 111 patients in the Clb-Obi arm. Across both groups, Bruton tyrosine kinase inhibitors were the most commonly used subsequent treatment.¹

The analysis also provided insight into outcomes among molecularly defined patient subgroups. Patients treated with Ven-Obi who had unmutated IGHV had shorter median PFS than those with mutated IGHV (64.7 vs 104.9 months; HR, 2.74; P < .001). Similarly, patients with a TP53 mutation or deletion had inferior outcomes compared with patients without TP53 abnormalities, with a median PFS of 49.0 vs 79.2 months, respectively (HR, 2.15; P = .001).¹

Multivariable analysis identified 17p deletion and unmutated IGHV status as independent adverse prognostic factors for PFS among patients receiving Ven-Obi.¹

Minimal residual disease (MRD) responses remained durable years after treatment completion. Six years after completing therapy, approximately 10.2% of patients in the Ven-Obi arm maintained undetectable MRD in peripheral blood, compared with 2.8% in the Clb-Obi arm. Rates of low- and high-level MRD were also numerically higher in the Ven-Obi arm.¹

Although OS data continued to favor Ven-Obi, the difference did not reach statistical significance. Median OS was not reached in the Ven-Obi arm and was 112.7 months in the Clb-Obi arm (HR, 0.80; P = .161).¹

Investigators also reported a higher incidence of second primary malignancies excluding nonmelanoma skin cancers with Ven-Obi compared with Clb-Obi (19.3% vs 11.2%; P = .047). However, no new safety signals emerged during long-term follow-up.¹

The findings reinforce the ability of a fixed-duration venetoclax-based regimen to provide prolonged disease control without continuous treatment. With a median PFS exceeding 6 years and a median TTNT approaching 8 years with Ven-Obi, the final CLL14 analysis continues to support the combination as a foundational frontline treatment option for patients with CLL and coexisting conditions.¹

REFERENCES

1. Fischer K, Al-Sawaf O, Robrecht S, et al. Venetoclax-obinutuzumab for previously untreated chronic lymphocytic leukemia: final results of the randomized CLL14 study. Presented at: 2026 European Hematology Association Congress; June 11-14, 2026; Stockholm, Sweden. Abstract S146.

2. Key statistics for chronic lymphocytic leukemia (CLL). American Cancer Society. Updated January 13, 2026. Accessed June 12, 2026. https://www.cancer.org/cancer/types/chronic-lymphocytic-leukemia/about/key-statistics.html

3. Chronic lymphocytic leukemia. Mayo Clinic. October 24, 2025. Accessed June 12, 2026. https://www.mayoclinic.org/diseases-conditions/chronic-lymphocytic-leukemia/survival-rates/gnc-20591002

4. Juárez-Salcedo LM, Desai V, Dalia S. Venetoclax: evidence to date and clinical potential. Drugs Context. 2019;8:212574. doi:10.7573/dic.212574

5. Majid A, Tsoulakis O, Walewska R, et al. BCL2 expression in chronic lymphocytic leukemia: lack of association with the BCL2 938A>C promoter single nucleotide polymorphism. Blood. 2008;111(2):874-877. doi:10.1182/blood-2007-07-098681

6. Sachdeva M, Dhingra S. Obinutuzumab: a FDA approved monoclonal antibody in the treatment of untreated chronic lymphocytic leukemia. Int J Appl Basic Med Res. 2015;5(1):54-57. doi:10.4103/2229-516X.149245