Patients with chronic lymphocytic leukemia (CLL) bearing TP53 mutations experience chemorefractory disease and are therefore candidates for targeted therapy. However, the significance of low-burden TP53 mutations with <10% variant allele frequency (VAF) remains a matter for debate. Herein, we describe clonal evolution scenarios of low-burden TP53 mutations, the clinical impact of which we analyzed in a "real-world" CLL cohort. TP53 status was assessed by targeted next-generation sequencing (NGS) in 511 patients entering first-line treatment with chemo- and/or immunotherapy and 159 patients in relapse before treatment with targeted agents. Within the pretherapy cohort, 16% of patients carried low-burden TP53 mutations (0.1% to 10% VAF). Although their presence did not significantly shorten event-free survival after first-line therapy, it affected overall survival (OS). In a subgroup with TP53 mutations of 1% to 10% VAF, the impact on OS was observed only in patients with unmutated IGHV who had not received targeted therapy, as patients benefited from switching to targeted agents, regardless of initial TP53 mutational status. Analysis of the clonal evolution of low-burden TP53 mutations showed that the highest expansion rates were associated with fludarabine, cyclophosphamide, and rituximab regimen in both first- and second-line treatments (median VAF increase, 14.8× and 11.8×, respectively) in contrast to treatment with less intense treatment regimens (1.6×) and no treatment (0.8×). In the relapse cohort, 33% of patients carried low-burden TP53 mutations, which did not expand significantly upon targeted treatment (median VAF change, 1×). Sporadic cases of TP53 mutations' clonal shifts were connected with the development of resistance-associated mutations. Altogether, our data support the incorporation of low-burden TP53 variants in clinical decision making.

Center of Molecular Medicine Central European Institute of Technology Masaryk University Brno Czech Republic

Department of Internal Medicine Hematology and Oncology University Hospital Brno and Faculty of Medicine Masaryk University; and

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Blood. 2021 Dec 23;138(25):2600-2601. doi: 10.1182/blood.2021012343. PubMed

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Stilgenbauer S, Eichhorst B, Schetelig J, et al. . Venetoclax in relapsed or refractory chronic lymphocytic leukaemia with 17p deletion: a multicentre, open-label, phase 2 study. Lancet Oncol. 2016;17(6):768-778. PubMed

O’Brien S, Jones JA, Coutre SE, et al. . Ibrutinib for patients with relapsed or refractory chronic lymphocytic leukaemia with 17p deletion (RESONATE-17): a phase 2, open-label, multicentre study. Lancet Oncol. 2016;17(10):1409-1418. PubMed

Brown JR, Byrd JC, Coutre SE, et al. . Idelalisib, an inhibitor of phosphatidylinositol 3-kinase p110δ, for relapsed/refractory chronic lymphocytic leukemia. Blood. 2014;123(22):3390-3397. PubMed PMC

Eichhorst B, Robak T, Montserrat E, et al. ; ESMO Guidelines Committee. Electronic address: clinicalguidelines@esmo.org . Chronic lymphocytic leukaemia: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Ann Oncol. 2021;32(1):23-33. PubMed

Hallek M, Cheson BD, Catovsky D, et al. . iwCLL guidelines for diagnosis, indications for treatment, response assessment, and supportive management of CLL. Blood. 2018;131(25):2745-2760. PubMed

Malcikova J, Tausch E, Rossi D, et al. ; European Research Initiative on Chronic Lymphocytic Leukemia (ERIC) — TP53 network . ERIC recommendations for TP53 mutation analysis in chronic lymphocytic leukemia-update on methodological approaches and results interpretation. Leukemia. 2018;32(5):1070-1080. PubMed PMC

Pospisilova S, Gonzalez D, Malcikova J, et al. ; European Research Initiative on CLL (ERIC) . ERIC recommendations on TP53 mutation analysis in chronic lymphocytic leukemia. Leukemia. 2012;26(7):1458-1461. PubMed

Zenz T, Eichhorst B, Busch R, et al. . TP53 mutation and survival in chronic lymphocytic leukemia. J Clin Oncol. 2010;28(29):4473-4479. PubMed

Gonzalez D, Martinez P, Wade R, et al. . Mutational status of the TP53 gene as a predictor of response and survival in patients with chronic lymphocytic leukemia: results from the LRF CLL4 trial. J Clin Oncol. 2011;29(16):2223-2229. PubMed

Stilgenbauer S, Schnaiter A, Paschka P, et al. . Gene mutations and treatment outcome in chronic lymphocytic leukemia: results from the CLL8 trial. Blood. 2014;123(21):3247-3254. PubMed

Stilgenbauer S, Sander S, Bullinger L, et al. . Clonal evolution in chronic lymphocytic leukemia: acquisition of high-risk genomic aberrations associated with unmutated VH, resistance to therapy, and short survival. Haematologica. 2007;92(9):1242-1245. PubMed

Malcikova J, Smardova J, Rocnova L, et al. . Monoallelic and biallelic inactivation of TP53 gene in chronic lymphocytic leukemia: selection, impact on survival, and response to DNA damage. Blood. 2009;114(26):5307-5314. PubMed

Landau DA, Carter SL, Stojanov P, et al. . Evolution and impact of subclonal mutations in chronic lymphocytic leukemia. Cell. 2013;152(4):714-726. PubMed PMC

Rossi D, Khiabanian H, Spina V, et al. . Clinical impact of small TP53 mutated subclones in chronic lymphocytic leukemia. Blood. 2014;123(14):2139-2147. PubMed PMC

Edelmann J, Tausch E, Landau DA, et al. . Frequent evolution of copy number alterations in CLL following first-line treatment with FC(R) is enriched with TP53 alterations: results from the CLL8 trial. Leukemia. 2017;31(3):734-738. PubMed PMC

Landau DA, Sun C, Rosebrock D, et al. . The evolutionary landscape of chronic lymphocytic leukemia treated with ibrutinib targeted therapy. Nat Commun. 2017;8(1):2185. PubMed PMC

Del Giudice I, Cafforio L, Cappelli LV, et al. . TP53 clonal and subclonal architecture in chronic lymphocytic leukemia patients under ibrutinib treatment [abstract]. Blood. 2018;132(suppl 1). Abstract 3119.

Nadeu F, Delgado J, Royo C, et al. . Clinical impact of clonal and subclonal TP53, SF3B1, BIRC3, NOTCH1, and ATM mutations in chronic lymphocytic leukemia. Blood. 2016;127(17):2122-2130. PubMed PMC

Brieghel C, Kinalis S, Yde CW, et al. . Deep targeted sequencing of TP53 in chronic lymphocytic leukemia: clinical impact at diagnosis and at time of treatment. Haematologica. 2019;104(4):789-796. PubMed PMC

Blakemore SJ, Clifford R, Parker H, et al. . Clinical significance of TP53, BIRC3, ATM and MAPK-ERK genes in chronic lymphocytic leukaemia: data from the randomised UK LRF CLL4 trial. Leukemia. 2020;34(7):1760-1774. PubMed PMC

Tausch E, Yosifov D, Massoudy-Touiserkan N, et al. . Minor mutations in TP53 associate with shorter PFS but not OS after chemoimmunotherapy: results from the Complement2 trial [abstract]. Leuk Lymphoma. 2019;61(suppl 1):141-143.

Bomben R, Rossi MF, Vit F, et al. . TP53 mutations with low variant allele frequency predict short survival in chronic lymphocytic leukemia [published online ahead of print 20 July 2021. Clin Cancer Res. doi: 10.1158/1078-0432.CCR-21-0701. PubMed DOI

Hallek M, Cheson BD, Catovsky D, et al. ; International Workshop on Chronic Lymphocytic Leukemia . Guidelines for the diagnosis and treatment of chronic lymphocytic leukemia: a report from the International Workshop on Chronic Lymphocytic Leukemia updating the National Cancer Institute-Working Group 1996 guidelines. Blood. 2008;111(12):5446-5456. PubMed PMC

Malcikova J, Stano-Kozubik K, Tichy B, et al. . Detailed analysis of therapy-driven clonal evolution of TP53 mutations in chronic lymphocytic leukemia. Leukemia. 2015;29(4):877-885. PubMed PMC

Pavlova S, Smardova J, Tom N, Trbusek M. Detection and Functional Analysis of TP53 Mutations in CLL. Methods Mol Biol. 2019;1881:63-81. PubMed

Kubesova B, Pavlova S, Malcikova J, et al. . Low-burden TP53 mutations in chronic phase of myeloproliferative neoplasms: association with age, hydroxyurea administration, disease type and JAK2 mutational status. Leukemia. 2018;32(2):450-461. PubMed PMC

Bouaoun L, Sonkin D, Ardin M, et al. . TP53 Variations in Human Cancers: New Lessons from the IARC TP53 Database and Genomics Data. Hum Mutat. 2016;37(9):865-876. PubMed

Tikkanen T, Leroy B, Fournier JL, Risques RA, Malcikova J, Soussi T. Seshat: A Web service for accurate annotation, validation, and analysis of TP53 variants generated by conventional and next-generation sequencing. Hum Mutat. 2018;39(7):925-933. PubMed

International CLL-IPI working group . An international prognostic index for patients with chronic lymphocytic leukaemia (CLL-IPI): a meta-analysis of individual patient data. Lancet Oncol. 2016;17(6):779-790. PubMed

Kotašková J, Pavlová Š, Greif I, et al. . ROR1-based immunomagnetic protocol allows efficient separation of CLL and healthy B cells. Br J Haematol. 2016;175(2):339-342. PubMed

Pavlova S, Malcikova J, Radova L, et al. . Interlaboratory comparison of NGS methods for detection of TP53 Variants <10% VAF: the first phase of an ERIC multicenter study on the clinical impact of low-frequent TP53 variants in CLL [abstract]. HemaSphere Abstract Book. 25th Congress of the European Hematology Association Virtual Edition, 11-14 June 2020. 2020;4:285-286.

Trbusek M, Smardova J, Malcikova J, et al. . Missense mutations located in structural p53 DNA-binding motifs are associated with extremely poor survival in chronic lymphocytic leukemia. J Clin Oncol. 2011;29(19):2703-2708. PubMed

Sutton LA, Hadzidimitriou A, Baliakas P, et al. ; European Research Initiative on CLL (ERIC) . Immunoglobulin genes in chronic lymphocytic leukemia: key to understanding the disease and improving risk stratification. Haematologica. 2017;102(6):968-971. PubMed PMC

Best OG, Gardiner AC, Davis ZA, et al. . A subset of Binet stage A CLL patients with TP53 abnormalities and mutated IGHV genes have stable disease. Leukemia. 2009;23(1):212-214. PubMed

Plevova K, Skuhrova Francova H, Burckova K, et al. . Multiple productive immunoglobulin heavy chain gene rearrangements inchronic lymphocytic leukemia are mostly derived from independent clones. Haematologica. 2014;99(2):329-338. PubMed PMC

Kotler E, Segal E, Oren M. Functional characterization of the p53 “mutome”. Mol Cell Oncol. 2018;5(6):e1511207. PubMed PMC

Baliakas P, Jeromin S, Iskas M, et al. ; ERIC, the European Research Initiative on CLL . Cytogenetic complexity in chronic lymphocytic leukemia: definitions, associations, and clinical impact. Blood. 2019;133(11):1205-1216. PubMed PMC

Burger JA, Landau DA, Taylor-Weiner A, et al. . Clonal evolution in patients with chronic lymphocytic leukaemia developing resistance to BTK inhibition. Nat Commun. 2016;7(1):11589. PubMed PMC

Blombery P, Anderson MA, Gong JN, et al. . Acquisition of the Recurrent Gly101Val mutation in BCL2 confers resistance to venetoclax in patients with progressive chronic lymphocytic leukemia. Cancer Discov. 2019;9(3):342-353. PubMed

Tausch E, Close W, Dolnik A, et al. . Venetoclax resistance and acquired BCL2 mutations in chronic lymphocytic leukemia. Haematologica. 2019;104(9):e434-e437. PubMed PMC

Kadri S, Lee J, Fitzpatrick C, et al. . Clonal evolution underlying leukemia progression and Richter transformation in patients with ibrutinib-relapsed CLL. Blood Adv. 2017;1(12):715-727. PubMed PMC

O’Brien S, Furman RR, Coutre S, et al. . Single-agent ibrutinib in treatment-naïve and relapsed/refractory chronic lymphocytic leukemia: a 5-year experience. Blood. 2018;131(17):1910-1919. PubMed PMC

Munir T, Brown JR, O’Brien S, et al. . Final analysis from RESONATE: Up to six years of follow-up on ibrutinib in patients with previously treated chronic lymphocytic leukemia or small lymphocytic lymphoma. Am J Hematol. 2019;94(12):1353-1363. PubMed PMC

Tausch E, Schneider C, Robrecht S, et al. . Prognostic and predictive impact of genetic markers in patients with CLL treated with obinutuzumab and venetoclax. Blood. 2020;135(26):2402-2412. PubMed

Ahn IE, Farooqui MZH, Tian X, et al. . Depth and durability of response to ibrutinib in CLL: 5-year follow-up of a phase 2 study. Blood. 2018;131(21):2357-2366. PubMed PMC

Döhner H, Stilgenbauer S, Benner A, et al. . Genomic aberrations and survival in chronic lymphocytic leukemia. N Engl J Med. 2000;343(26):1910-1916. PubMed

Kato S, Han SY, Liu W, et al. . Understanding the function-structure and function-mutation relationships of p53 tumor suppressor protein by high-resolution missense mutation analysis. Proc Natl Acad Sci USA. 2003;100(14):8424-8429. PubMed PMC

Cho Y, Gorina S, Jeffrey PD, Pavletich NP. Crystal structure of a p53 tumor suppressor-DNA complex: understanding tumorigenic mutations. Science. 1994;265(5170):346-355. PubMed

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