Prevalence of BTK and PLCγ2 Mutations in Patients relapsing under Ibrutinib. Lydia Scarfò Silvia Bonfiglio Lesley Ann Sutton

Transcription

1 Prevalence of BTK and PLCγ2 Mutations in Patients relapsing under Ibrutinib Lydia Scarfò Silvia Bonfiglio Lesley Ann Sutton

2 Patients relapsing on ibrutinib are the new unmet clinical need Woyach J et al. JCO 2017

3 BTK and PLCγ2 mutations Bruton Tyrosine Kinase (BTK) Phospholypase C gamma 2 (PLCγ2) Ahn IE et al. Blood. 2017

4 Study Objectives PRIMARY: To define the prevalence of BTK and/or PLCγ2 mutations in chronic lymphocytic leukemia (CLL) patients relapsing under ibrutinib SECONDARY: To define the prevalence of BTK and/or PLCγ2 mutations in CLL patients responding to ibrutinib after at least 1 year of treatment To define the estimated variant allele frequency (VAF) in CLL patients relapsing under ibrutinib To define the estimated variant allele frequency (VAF) in CLL patients responding to ibrutinib after at least 1 year of treatment

5 Study Design Multicenter, international study 14 Participating sites 6 Italian 1 Croatian 3 British 1 Australian 2 Greek 1 Argentinian Observational 50 IBRUTINIB RELAPSING CASES prior to ibrutinib initiation at relapse 50 IBRUTINIB RESPONDING CASES prior to ibrutinib initiation after at least 1 year of treatment Retrospective Frozen viable cell samples to perform high-sensitivity next-generation sequencing (NGS) Clinical data (demographic and disease characteristics, treatment information, ibrutinib treatment information, salvage treatment information) to be collected for all cases.

6 Methods: Next Generation Sequencing (NGS) Cell preparation: B cell purification. Library preparation: Custom panel targeting BTK and PLCγ2 (all coding exons) HaloPlex HS kit (Agilent Technologies) High sensitivity amplicon-based targeted resequencing method Molecular barcodes allow for the identification of duplicated reads, improving base calling accuracy even at low allelic frequencies (<1% VAF) compared to conventional NGS methods 50 ng DNA input required Sequencing: NextSeq 500 platform (Illumina)

7 Patient population Abstract Analysis Overall 26 pts Relapsed 13 Responders 13 Current Analysis Overall 54 pts Relapsed 22 Responders 32 Final Analysis Overall 77 pts Relapsed 29 Responders 48

8 Patient cohort Characteristics Relapsed n = 13 Responsive n = 13 Overall n = 26 Median age, y (range) 61 (48-77) 72 (59-84) 66 (48-84) Gender (M:F) 9:4 7:6 16:10 # prior therapies (0/1/ 2) 0/1/12 3/4/6 3/5/18 Del17p Pos/Total 5/13 3/12 8/25 TP53 Mut/Total 6/10 4/11 10/21 IGHV Unmut/Total 7/9 9/13 16/22 Duration of ibrutinib treatment (months) Best Response to ibrutinib CR/PR 25 (3-57) 24 (16-58) 24.5 (3-58) 0/13 2/11 2/24

9 Relapsed cases Pt # Age, y Gender Prior therapies Cytogenetics TP53 mutations IGHV status 1 48 F 1 Del17p Mutant Unmutated 2 62 M 4 Del11q Mutant NA 3 60 M 4 Del11q NA Mutated 4 69 F 3 Trisomy 12 Mutant Mutated 5 70 M 3 Del11q Wild type Unmutated 6 77 M 4 Del17p Mutant Unmutated 7 57 M 4 Del17p Mutant Unmutated 8 61 M 2 Del11q Wild type Unmutated 9 57 M 3 Del13q Wild type Unmutated F 4 Del11q NA NA M 3 Del17p Mutant NA M 4 Del17p NA NA F 2 del11q Wild type Unmutated

10 BTK mutations Pt # Gene Exon AA change WT/MT codon VAF, % 1 BTK 15 C481R c.t1441c BTK 15 C481S C481S c.t1441a c.g1442c BTK 15 C481S c.g1442c BTK 15 C481S c.g1442c BTK 15 C481S c.g1442c BTK 15 C481S c.g1442c BTK 15 C481S c.g1442c RE BTK 15 C481S c.g1442c 19.47

11 Salvage Treatment and Outcome after ibrutinib Pt # Next line Response Months after Ibr discontinuation 1 Idelalisib+R PR 15 Alive 2 Venetoclax Failure 1 Dead 3 Idelalisib+R Failure 3 Dead 4 Venetoclax PR 5 Alive 5 Venetoclax NA 2 Alive 6 Idelalisib+R Failure 16 Alive 7 Venetoclax PR 2 Alive 8 Venetoclax Failure 5 Alive 9 Idelalisib+R Failure 11 Dead 10 Obinutuzumab CR 14 Dead 11 Obinutuzumab+HDMP PR 11 Dead 12 Idealisib+R PR 18 Dead 13 Venetoclax PR 12 Dead Status at last follow up

12 November 2017: Collection of samples Study Timeline January-April 2018: Cell purification, DNA extraction May 2018: Library preparation May-June 2018: Sequencing and analysis EHA Abstract submission June 2018: Data analysis completion September 2018: Submission for publication

13 ERIC Office: Natalie Sorolla Paolo Ghia Lesley Ann Sutton, Silvia Bonfiglio, Richard Rosenquist Università Vita-Salute San Raffaele, Milan Antonella Capasso, Pamela Ranghetti University of Eastern Piedmont, Novara Gianluca Gaidano, Riccardo Moia Clara Deambrogi University of Melbourne, Melbourne Constantine Tam Città della Salute e della Scienza, University of Turin, Turin Marta Coscia, Candida Vitale, Valentina Griggio University of Padua, Padua Livio Trentin, Andrea Visentin S. Giovanni Battista Hospital, Turin Lisa Bonello Laiko Hospital, University of Athens, Athens Panayiotis Panayiotidis, Maria Dimou, Maria Roumelioti IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan Gianluigi Reda University Hospital NHS Trust, Southampton Francesco Forconi, Samantha Drennan G. Papanicolaou Hospital, Thessaloniki Niki Stavroyianni University of Cambridge, Cambridge Ingo Ringshausen, Andrew Moore Dubrava University Hospital, Zagreb Ozren Jaksic Royal Bournemouth Hospital, Bournemouth Zadie Davis Fundaleu, Buenos Aires Carolina Pavlovsky, Evelyn Casares Karolinska Institutet, Stockholm Diego Cortese, Aron Skaftason Institute of Applied Biosciences, CERTH, Thessaloniki Kostas Stamatopoulos, Stavroula Ntoufa The study was conducted thanks to the support of SUNESIS

14 HALF OF CHRONIC LYMPHOCYTIC LEUKEMIA PATIENTS RELAPSING UNDER IBRUTINIB CARRY BTK AND PLCγ2 MUTATIONS: A EUROPEAN RESEARCH INITIATIVE ON CLL (ERIC) REAL-WORLD STUDY Lesley Ann Sutton, Silvia Bonfiglio, Lydia Scarfò, Gianluca Gaidano, Livio Trentin, Lisa Bonello, Panayiotis Panayiotidis, Gianluigi Reda, Francesco Forconi, Niki Stavroyianni, Constantine Tam, Marta Coscia, Ingo Ringshausen, Ozren Jaksic, Zadie Davis, Carolina Pavlovsky, Antonella Capasso, Pamela Ranghetti, Diego Cortese, Aron Skaftason, Kostas Stamatopoulos, Richard Rosenquist, Paolo Ghia