SAKK 38/19 Therapy adjustment based on PET/CT and circulating tumor DNA in patients with diffuse large B-cell lymphoma

The study investigates the treatment of DLBCL: Group A: Testing the efficacy and safety of a substance that targets a specific genetic alteration of DLBCL in combination with the standard therapy R-CHOP. In this study, we want to investigate whether the addition of the active substance acalabrutinib to R-CHOP treatment (A-R-CHOP) can improve efficacy. We are also investigating the safety and tolerability of treatment with A-R-CHOP. Group C: Testing a reduction of treatment cycles with R-CHOP in study participants without the specific genetic alteration with optimal imaging and molecular response. By means of positron emission tomography in combination with computer tomography (PET-CT), the response to R-CHOP therapy can be examined. Samples of circulating tumor cells are measured at the same time as the PET/CT scan. If the tumor responds well to the 2 cycles of R-CHOP, this is accompanied by a reduction in tumor mass. We assume that under these conditions the standard treatment can be reduced from 6 to 4 cycles of R-CHOP followed by 2 cycles of Rituximab. Group D: Review of the clinical course of DLBCL with optimal imaging response but inadequate molecular response or, conversely, an inadequate imaging response but optimal molecular response. If the tumor does not respond or responds inadequately to the 2 cycles of R-CHOP, this is accompanied by little or no reduction in tumor mass. Under these conditions, the standard number of cycles must not be reduced. Group B: Testing the efficacy of this substance in combination with standard therapy in DLBCL with an inadequate response to R-CHOP. If both a reduction in the signals in the PET/CT examination and a reduction in the circulating number of tumor cells are missing, the further R-CHOP cycles are supplemented with acalabrutinib.

(BASEC)