Comparison of three therapies in patients with previously untreated chronic lymphocytic leukemia (CLL) or small cell lymphocytic lymphoma (SLL)
Comparison of three therapies in patients with previously untreated chronic
lymphocytic leukemia (CLL) or small cell lymphocytic lymphoma (SLL):
Time-limited therapy (12 cycles) with venetoclax and obinutuzumab
Time-limited therapy (15 cycles) with venetoclax and pirtobrutinib
Therapy with venetoclax and pirtobrutinib, of which the duration depends on
the individual response of the treated person.
To determine the response, the number of cancer cells in the blood is
measured regularly (individual minimal residual disease, MRD).
The aim is to use the MRD to control the duration of treatment and thereby to
improve the treatment results.
Summary of the protocol
CLL is the most common form of leukemia in adults in Switzerland. SLL is a subtype
of CLL. Various drugs are available for the treatment of these diseases. Which drug
or combination of drugs is used and how long the treatment lasts, depends among
other things, on the characteristics of the cancer cells and the stage of the disease.
For some patients, treatment is limited in time, for others it is permanent. However, it
is not always clear whether temporary treatment or permanent treatment is better.
It may be possible to improve CLL therapy if the number of CLL cells in the blood of a
person undergoing treatment is measured regularly; treatment is only stopped when
no more CLL cells can be detected in the blood. This form of therapy is known as
MRD-guided therapy. MRD measurement involves determining the number of CLL
cells in the treated person's blood. MRD measurement is already standard for other
cancers, but not yet for the treatment of CLL. This is why MRD-guided therapy is
investigated for CLL in this trial. The aim is to improve CLL therapy and adapt it more
closely to the needs of patients. The drugs used in the trial are venetoclax,
obinutuzumab and pirtobrutinib. Venetoclax and obinutuzumab are approved for CLL
therapy. Pirtobrutinib is authorized in the countries of the European Union for the
treatment of CLL relapse and; in Switzerland, pirtobrutinib is authorised for the
treatment of another cancer, but not for CLL therapy.
Disease being investigated in the trial
Chronic lymphocytic leukemia (CLL) or small cell lymphocytic lymphoma (SLL)
Treatment being investigated in the trial
The trial participants are randomly assigned to one of three treatment groups
(randomization).
- Group A: Treatment with venetoclax (tablets) and obinutuzumab (infusions) for
approx. 11 months (12 therapy cycles) - Group B: Treatment with venetoclax (tablets) and pirtobrutinib (tablets) for
approx. 14 months (15 treatment cycles) - Group C: Treatment with venetoclax (tablets) and pirtobrutinib (tablets). The
duration of treatment depends on the results of the MRD measurement.
Treatment is discontinued if no CLL cells are detected in the blood in two
consecutive MRD measurements or if the number of CLL cells in the blood no
longer decreases. The therapy lasts between 14 and 33 months (15 to 36
therapy cycles).
The results achieved in the three groups are compared with each other.
Inclusion criteria
The people who take part in the trial must fulfil various requirements. The most
important include:
- Age: at least 18 years.
Exclusion criteria
Not all people with CLL/SLL can take part in the trial. The most important exclusion
criteria that include
- The CLL/SLL has already been treated once.
- The disease is so advanced that the person requires treatment other than trial
therapies. - The person concerned has other significant illnesses, for example another
cancer, a serious infectious disease or an increased risk of bleeding.