AbbVie today announced new, updated results from the Phase 3 MURANO and CLL14 clinical trials evaluating venetoclax fixed duration treatment combinations at the virtual 62nd American Society of Hematology (ASH) Annual Meeting & Exposition (abstracts 125, 127, and 1310, respectively).

These findings add to the growing body of data supporting the use of venetoclax in first-line or previously treated chronic lymphocytic leukaemia (CLL) patients.

"MURANO and CLL14 provide a look at the benefits of fixed duration venetoclax combinations in helping many patients to achieve sustained progression-free survival," said John Hayslip, M.D., M.S.C.R., executive medical director, AbbVie.

"These responses reinforce that with venetoclax, it is possible for CLL patients to complete treatment and live longer without their disease progressing."

Data from the MURANO and CLL14 trials presented at ASH reinforce that CLL patients who have relapsed or have not started treatment and receive a venetoclax regimen can experience long-lasting responses, even after stopping treatment, compared to standard of care treatment options.

MURANO Five-Year Analysis

The results of the final, descriptive analysis of the MURANO trial (median follow-up of 59.2 months with all patients off venetoclax in combination with rituximab  treatment for at least three years demonstrated the following:

Investigator (INV)-assessed progression-free survival (PFS): Patients with relapsed or refractory (R/R) CLL on fixed duration VenR had a median PFS of 53.6 months (95% CI: 48.4-57.0) compared to 17.0 months (95% CI: 15.5-21.7) with bendamustine plus rituximab (BR; HR 0.19, 95% CI: 0.15-0.26).

Overall survival (OS): The OS estimate was 82.1% (95% CI: 76.4-87.8) with VenR compared to 62.2% (95% CI: 54.8-69.6) for BR (HR 0.40, 95% CI: 0.26-0.62), median not reached in either arm.

Minimal residual disease (MRD) status at completion of VenR treatment: Patients who achieved MRD-negativity without disease progression at the end of their treatment course had improved PFS and OS compared to patients with MRD.

MRD refers to the small number of cancer cells that remain in the body after treatment.

The number of remaining cells may be so small that they do not cause any physical signs or symptoms and often cannot even be detected through traditional methods.

Consistent safety profile: The safety profile of the VenR combination is consistent with the known safety profile of each individual therapy alone.

No new, serious safety issues were observed in the five-year MURANO updated analysis.

According to the Leukemia & Lymphoma Society, MRD refers to the small number of cancer cells that remain in the body after treatment.

The number of remaining cells may be so small that they do not cause any physical signs or symptoms and often cannot even be detected through traditional methods, this is known as undetectable MRD (uMRD). Doctors use MRD/uMRD to measure the effectiveness of treatment and to predict which patients are at risk of relapse.

CLL14 Analyses

Data from descriptive analyses of the Phase 3 CLL14 trial was also presented today evaluating the role of MRD measurements in clinical trials.

One analysis showed that patients with previously untreated CLL and co-existing medical conditions who had partial response (PR) after treatment with venetoclax in combination with obinutuzumab (Ven-Obi) had a similar outcome as patients with complete response (CR) when uMRD levels were achieved.

These data suggest that patients on the venetoclax combination with uMRD levels and PR had longer PFS than patients with MRD and CR.

This is significant because patients with CLL who show a PR to chemoimmunotherapy have a poorer prognosis than patients with CR.

These results were not tested for statistical significance. 

The second analysis looked at clonal growth patterns – or how quickly cancer cells grow and spread – in patients treated within the CLL14 trial.

The findings from the analysis shed light on which patient group may be at risk of relapsing despite initial MRD response.

The four-year, follow-up analysis showed an OS rate of 85.3% with Ven-Obi versus 83.1% with chlorambucil in combination with obinutuzumab (Obi-Clb; HR 0.85, 95% CI [0.54-1.35]; P=0.4929).

Source: AbbVie