Improved OS with obinutuzumab in the CLL11 study

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Published: 15 Jun 2018
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Dr Valentin Goede - St. Marien-Hospital, Cologne, Germany

Dr Goede presents data at EHA 23 from a final analysis of treating CLL with obinutuzumab in place of rituximab alongside chlorambucil chemotherapy.

He outlines the previously reported data, culminating in the final analysis showing an improved progression-free survival and improved overall survival.

Overall, Dr Goede recommends this as a new standard of care for these patients.

For more on these findings, watch his interview with ecancer.

At the meeting we present results of the final analysis of the CLL11 study.

Here are my disclosures.

As you all know, chronic lymphocytic leukaemia is a disease that primarily affects older people and the purpose of the trial was to improve the treatment of these elderly CLL patients with comorbidities by introducing immuno-chemotherapy because chemotherapy alone was the standard treatment at the beginning of the trial still.

Another goal was to compare obinutuzumab, that is a type 2 glyco-engineered CD20 antibody which was new at the launch of the trial, with rituximab, a broadly known type 1 antibody targeting CD20.

This was the trial design, this was a randomised phase III trial and, as already said, the trial recruited around 800 patients who were older, the median age was 73 years, and who carried a significant burden of comorbidities.

Then we had a three-arm design here with a common comparator which was chlorambucil monotreatment and then we had the combination of chlorambucil with rituximab and the combination of chlorambucil with obinutuzumab in that trial.

We had PFS as a primary endpoint and three pairwise comparisons in this trial.

The primary analysis was already done five years ago and actually presented at EHA here in Stockholm in 2013.

There was also an updated analysis two years later. Basically, these analyses showed superiority of chemo-immunotherapy over chemotherapy alone with regards to PFS, this was true for obinutuzumab and rituximab, and also overall survival which was only true for obinutuzumab.

The trial for the head-to-head comparison of the two antibody arms also showed superiority of chemo-immunotherapy with obinutuzumab when compared with rituximab with regard to progression free survival and time until next treatment but not overall survival at that time point.

Now we have run the final analysis last year after closing the trial.

We now have a median observation time of five years and the results, to say briefly, robustly confirm previous observations.

We also did not see new safety signals and importantly in this analysis we could demonstrate a statistically significant and also clinically meaningful overall survival benefit of obinutuzumab over rituximab when combined with chlorambucil in this patient population.

I’ll briefly flip through three Kaplan-Meier plots to illustrate this.

So this was the primary endpoint, progression free survival, here.

As you can see the PFS superiority of obinutuzumab over rituximab was confirmed here with a nearly doubling of the median progression free survival.

This benefit translated into a clinically meaningful prolongation of the time to the next anti-leukemic therapy.

Again, this was virtually a doubling in the median time to next treatment in favour of the obinutuzumab arm.

These are the overall survival curves for this recent analysis and, as you can see, this final analysis of the CLL11 trial now demonstrates a prolongation of overall survival in the obinutuzumab arm compared to the rituximab arm.

The median overall survival in the rituximab arm was 73 years whereas it was not reached in the obinutuzumab arm.

The hazard ratio was 0.76.

We consider these results clinically meaningful and also remarkable in the context of the long follow-up of the trial.

So, we conclude from these data that in the present treatment landscape of CLL we think that these data support the use of obinutuzumab and chlorambucil as a front-line therapy in patients with CLL who are old and have comorbidities.

If one decides for a chlorambucil-based chemo-immunotherapy in these patients we think these data strongly suggest to use obinutuzumab and not a type 1 antibody in this setting.

We also think that these data reassures the choice of using obinutuzumab chlorambucil as a valid comparator arm in ongoing trials testing new treatments in this vulnerable patient population.

Finally, as you all know, from these trials there are new combinations being tested and this data is a good basis to suggest obinutuzumab is a preferred CD20 antibody for future combination regimens in CLL.

Thank you for your attention.