DIRECT was a prospective, multisite study assessing the feasibility and utility of circulating tumor DNA (ctDNA) in 188 patients with aggressive B-cell non-Hodgkin lymphoma using a lymphoma-customized assay and open-source pipeline. CtDNA fraction assessed by copy number alterations in pre-treatment plasma identified high-risk patients more effectively than existing clinical risk scores. In 74.5% of cases ctDNA was equivalent or superior to biopsy for genetic profiling. Patients not suitable for ctDNA genotyping had low tumor volumes and could be predicted from simple clinical factors. Finally, a phased variant-supported minimal residual disease (MRD) assay was predictive of outcomes in all groups analyzed. Patients achieving ctDNA clearance at end of treatment had an extremely low 2-year progression rate (<5%). However, false positive MRD results were common in patients with transformed indolent lymphoma. This study highlights the considerable potential, but also the caveats and limitations, of ctDNA technology when applied to aggressive B-cell lymphoma.

DJH: reports research funding from Astra Zeneca and GSK. SB: research funding from Beigene, F Hoffman la Roche and Takeda SKM: Speaker fees and conference travel: SOBI, Alexion, AZ DH and VM: employment and stock ownership AstraZeneca

This study was sponsored by Cambridge University Hospitals NHS Foundation Trust and the University of Cambridge and financed by a grant from the Mark Foundation for Integrated Cancer Medicine to the CRUK Cancer Centre and by AstraZeneca. We thank Cambridge Clinical Trials Unit Cancer Theme for their core staff support and the clinical trials support staff at all participating sites. This work was supported by the Cancer Molecular Diagnostics Lab at the Cancer Research UK Cambridge Centre [CTRQQR2021\100012] and by Tissue Bank. We thank CMDL technical staff for blood processing, extractions and library prep and Katie Honan (CMDL) for sequencing data transfer. This research was supported by the NIHR Cambridge Biomedical Research Centre (NIHR203312) and NIHR Leicester Biomedical Research Centre (NIHR203327). The views expressed are those of the authors and not necessarily those of the NIHR or the Department of Health and Social Care. NHC was supported by a clinical research training fellowship from CRUK Cambridge Centre. DJH was supported by a fellowship from Cancer Research UK (CRUK; RCCFEL\100072) and received core funding from Wellcome (203151/Z/16/Z) to the Wellcome-MRC Cambridge Stem Cell Institute and from the CRUK Cambridge Centre (A25117).

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The study was reviewed and given favorable opinion by East of England, Cambridge Central Research Ethics Committee (20/EE/0068) and the UK Health Research Authority. All patients provided written informed consent prior to participating. The study was performed in accordance with the spirit and the letter of the declaration of Helsinki, the conditions and principles of ICH E6 Good Clinical Practice, the protocol and applicable local regulatory requirements and laws.

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

All sequencing files have been deposited at the European Genome Phenome Archive (EGA) with accession number: EGAS50000000968.