Adaptive Biotechnologies and collaborators from several academic institutions have presented data showing that MRD testing using the company's clonoSEQ® Process at one year post-transplant can predict both relapse-free and overall survival (RFS and OS, respectively) in patients with chronic lymphocytic leukemia (CLL) who are treated with reduced intensity conditioning followed by allogeneic (donor) stem cell transplant. The data was presented in a poster session Monday evening at the American Society of Hematology (ASH) Annual Meeting taking place in Orlando, FL.

"MRD testing allows us to take proactive measures, such as implementation of immune modulation or maintenance treatment, in MRD-positive patients who are at risk of relapse, while sparing those patients with no evidence of disease from the potential toxicity of additional treatment," said Aaron Logan, M.D., Ph.D., Assistant Professor, University of California, San Francisco (UCSF) School of Medicine, and lead author of the study.

A previous study had shown the utility of the clonoSEQ Process for predicting relapse-free survival in a single-institution cohort of CLL patients undergoing reduced-intensity allogeneic stem cell cell transplantation. In the current study a total of 87 patients from Stanford University Medical Center, MD Anderson Cancer Center, and the Dana Farber Cancer Institute were retrospectively analyzed to measure the amount of MRD present at one year post transplant.

Among patients alive and in remission one year after transplant, those who were MRD-positive (greater than one leukemia cell per one million total white blood cells) had worse outcomes. Fifty-nine percent of MRD-positive patients relapsed, with a median time to relapse of 2.1 years, compared to only 5.3 percent of the MRD-negative patients relapsing, with a median time to relapse of 7.5 years (hazard ratio (HR)=11, 95 percent CI: 4.3-28, p<0.0001). MRD-positivity one year post-transplant was also associated with reduced long term overall survival (HR=2.6, 95 percent CI: 1.1-6.4, p=0.03).

"These new data demonstrating the prognostic power of the clonoSEQ Process in post-transplant CLL patients are part of a growing body of evidence across lymphoid cancers showing the relevance of achieving and measuring deep levels of response to therapy," said Tom Willis, Ph.D., Senior Vice President and General Manager, Diagnostic Products, Adaptive Biotechnologies.

Abstract No. 4340: Molecular Remission One Year Following Reduced-Intensity Allogeneic Hematopoietic Cell Transplantation for Chronic Lymphocytic Leukemia Predicts Relapse-Free and Overall Survival: A Multi-Institutional Landmark Analysis

About Minimal Residual Disease

Minimal residual disease (MRD) refers to cancer cells that may remain in the body of a person with lymphoid cancer after treatment. These cells are present at levels undetectable by traditional microscopic examination (also called morphologic examination) of blood, bone marrow or a lymph node biopsy. Sensitive molecular technologies, such as the next-generation sequencing utilized by the Adaptive Biotechnologies clonoSEQ MRD Test, are needed for reliable detection of very low levels of MRD.

About the clonoSEQ® Process

The Adaptive Biotechnologies clonoSEQ Process enables physicians to utilize sequencing-based minimal residual disease (MRD) detection as an aid to clinical decision making for patients with lymphoid cancers (blood cancers). With its ability to detect cancer cells at a level as low as one per one million white blood cells, the clonoSEQ MRD Test is one to two orders of magnitude more sensitive than other methods of MRD detection, such as ASO-PCR and flow cytometry. The clonoSEQ Process was previously marketed as the ClonoSIGHT™ process by Sequenta, Inc., which was acquired by Adaptive Biotechnologies in January 2015.

MRD detection and quantification using the clonoSEQ Process involves two steps that are easily integrated into patient care. In the first step, the clonoSEQ ID Test, cancer cell DNA sequences are identified in a diagnostic sample. In the second step, the clonoSEQ MRD Test, follow-up samples are screened for the previously identified sequences in order to detect residual disease. ClonoSEQ test results are generated in seven days using the company's CLIA-certified, CAP-accredited laboratory. These results are provided to the ordering physician in a simple, actionable report that shows a patient's MRD status and level, as well as MRD trends over time via a secure online portal.