Optimal Management of CML in 2015

Neil Shah, MD PhDEdward S. Ageno Distinguished Professor in Hematology/OncologyLeader, Hematopoietic Malignancies ProgramHelen Diller Family Comprehensive Cancer Center at UCSFSan Francisco, CaliforniaOptimal Management of CML in 2015

1The importance of CML to molecular oncologyCML was the first malignancy shown to be associated with a particular genetic mutationCML was the first disease to be treated with small molecule tyrosine kinase inhibitors (TKI)Lessons learned from TKI treatment have informed multiple other oncologic areas

In 2015, the diagnosis, treatment, and monitoring of malignancies is increasingly molecular and personalized, and to a large extent CML has paved the way2CML - clinical featuresApproximately 6000 new US cases per yearmedian age at presentation: 53 yearsmen comprise approximately 60 percent of casesdisease is clinically divided into two phaseschronic phaseadvanced phaseAccelerated phaseBlast crisis phaseMyeloid blast phaseLymphoid blast phase3CML - chronic phaseApproximately 40 percent of patients are without symptoms (fatigue)85 percent of newly diagnosed CML cases present in the chronic phaseMedian duration of chronic phase (prior to 2000) approximately 4-6 yearsAfter 2000 - unknown, greater than 10 yearsInterventions can lead to durable responses in chronic phaseMedical therapy (interferon, TKIs)Stem cell transplantation4CML - blast crisis phaseFailure of normal development of blood cellsResponds poorly to medical interventionbleeding, infections, anemia commonMedian survival approximately 6 months

5First hint at the cause of CML:Forrest et al, 2008; Bakshi et al, 2008; Image courtesy of Larry Beauregard, Jr., PhD.

46,XX,t(9;22)(q34;q11.2)6Purpose of this & the following 3 slides are to note the proper use, advantages, and limitations of each assay used to diagnose CML

Dr. Beauregard can be reached by calling (207)-973-7357, or by e-mail at lbeauregard@emh.org

http://images.google.com/imgres?imgurl=http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/Ph1Karyotype.gif&imgrefurl=http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/C/CML.html&usg=__GbQY2sgxukeQYT6-TlkSH_yfPqw=&h=383&w=384&sz=29&hl=en&start=1&itbs=1&tbnid=o1n4zzzt_E2aNM:&tbnh=123&tbnw=123&prev=/images%3Fq%3Dcml%2Bkaryotype%26gbv%3D2%26hl%3Den6Ph chromosomeBCR-ABL (activated tyrosine kinase)

BCRABLCMLThe Philadelphia (Ph) Chromosome Leads to CML7The Ph-chromosome arises from the reciprocal translocation of sequences from the Breakpoint Cluster Region or BCR gene on chromosome 22 and from the Abelson oncogene on chromosome 9.

The resulting BCR-ABL fusion gene is known as the Philadelphia chromosome.

The molecular consequence of this fusion is the deregulated protein tyrosine kinase known as BCR-ABL.

It has been shown that expression of BCR-ABL alone can induce a CML-like disease in mice. This coupled with the studies that showed the the kinase activity of BCR-ABL is required for this transforming ability clearly points toward BCR-ABL as a natural target for drug-mediated inhibition in CML therapy.

Recently, Novartis Pharmaceuticals has developed such a drug...

FDA Approval, May 20018IMATINIB AS FRONTLINE THERAPY FOR CML9IMATINIB AS FRONTLINE THERAPY FOR CML7-8 year update of newly-diagnosed Chronic Phase CML patients treated with 400 mg daily imatinibOBrien et al. ASH 2008, Abstract 18610Annual Event Rates: Imatinib Arm

Year% With EventEventLoss of CHR,Loss of MCR,AP/BC,Death during treatmentAP/BC3.37.54.81.71.52.81.60.90.80.30.502.00.4KM estimated EFS at 8 years = 81%KM estimated rate without AP/BC at 8 years = 92%*Total events (n=3) including two CML-unrelated deaths (n=2), and one patient with progression to AP/BC*Deininger et al. ASH 2009, Abstract 11260.41.2#11117th year after randomization (using life-table method): 1 AP/BC Patient 0759_00021 who died of unknown cause which was still suspected to be due to CML and thus counted as AP/BC although there was now values indicating progression5 Events 3 unconfirmed loss of MCyR (but 1 had increasing early forms of differentials, 1 had increased platelets) 1 death (Respiratory failure, in CML response)1 death (see above, suspected to be related to CML by investigator)

8th year after randomization (not shown above): Patient 0155_00001 with documented AP/BC (late CCyR patient), received mostly 200-300 mg only

Overall Survival (ITT Principle): Imatinib ArmEstimated overall survival at 8 years is 85% (93% considering only CML-related deaths)Survival: deaths associated with CMLOverall Survival% Without Event0102030405060708090100Months Since Randomization01224364860728496

Deininger et al. ASH 2009, Abstract 1126#1212Leitner AA, et al. Internist (Berl). 2011;52:209-217. Yrs After DiagnosisSurvival Probability (All Ph+ CML Disease Phases)026481016182022121400.20.10.50.60.70.80.91.00.30.41995-2008, IFN- or SCT1986-2003, IFN-1983-1994, busulfan1983-1994, hydroxyurea1997-2008, IFN- or SCT plus 2nd-line imatinib2002-2008, imatinib*Best Available Therapy 5-Yr OS, %Imatinib* 93IFN- or SCT plus 2nd-line imatinib 71IFN- or SCT 63IFN- 53Hydroxyurea46Busulfan38197020001990198019602010Imatinib Has Revolutionized the Therapeutic Landscape for Patients With CML*CML IV. CML IIIA. CML III.clinicaloptions.com/oncologyA Healthcare Team Approach to Optimal Care13CML, chronic myeloid leukemia; IFN-, interferon-alpha; OS, overall survival; Ph, Philadelphia chromosome; SCT, stem cell transplant.

The 5-year rates of overall survival (OS) for patients with Philadelphia-positive (Ph+) chronic myeloid leukemia (CML) have been increasing over the past several decades.1The introduction of therapies with improved efficacies has driven this increase.In particular, the use of imatinib (either as second-line or frontline therapy) has significantly improved the OS of patients with Ph+ CML.1Frontline imatinib was associated with a 93% OS, an unprecedented survival rate for patients with CML.2

References1.Hochhaus A. In: Faderl S, Kantarjian H, eds. Leukemias: Principles and Practice of Therapy. 2010:271-280.2. Hehlmann R et al. Haematologica. 2009;94(s2):193. Abstract 478.13Huang X, et al. Cancer. 2012;118:3123-3127.YrCases (n)Estimate of Rapidly Increasing CML PrevalenceIncidence 4700/yrAge-matched mortality ratio vs normal population = 1.53Accounts for increased US population to 392 million in 2050 200,000180,000160,000140,000120,000100,00080,00060,00040,00020,00020002005201020152020202520302035204020452050clinicaloptions.com/oncologyA Healthcare Team Approach to Optimal CareCML, chronic myeloid leukemia14Imatinib - ConclusionsImatinib (400 mg daily) remains the standard dose for chronic phase CML patients85% overall survival with imatinib exceeds that of all other CML therapies, with 7% patients dying from CML after eight years 82% of patients treated with imatinib achieved a CCyR55% of all imatinib randomized patients are still on study treatment, and nearly all of these are in CCyRResponses are typically durable, and the annual risk of progression appears to decrease after 2-3 yearsNo new safety findings seen with long term follow-upMany patients experience chronic lower grade toxicities

15Chronic Phase CML Treatment Landscape EvolutionImatinibapproved by FDA2000201020122008200620042002#You may not show or distribute this item outside BMS.You may NOT discuss the information in this item with customers.Speaker NotesSince initial discovery of the Philadelphia chromosome in 19601 and FDA approval of GLEEVEC (imatinib) in 2001,2 the treatment landscape of CML continues to evolveRead as stated

References1. Wong S, Witte O. Annu Rev Immunol. 2004;22:247306.2. GLEEVEC (imatinib) Full Prescribing Information. Novartis.

16MONITORING DISEASE IN PATIENTS WITH CML17Normal CBC and differential, no extramedullary diseaseComplete hematologic response (CHR)

DefinitionLevel of ResponseNegativity by RT-PCR (4.5 log reduction of BCR-ABL)Complete molecular response3-log reduction of BCR-ABLMajor molecular response (MMR)

0% Ph-positive metaphases*Complete cytogenetic response (CCyR)

1%35% Ph-positive metaphases*Partial cytogenetic response (PCyR)

36%90% Ph-positive metaphases*Minor cytogenetic response

Treatment ResponseAdapted from NCCN Clinical Practice Guidelines in Oncology: chronic myelogenous leukemia. V.3.2008. http://www.nccn.org. Accessed 02/04/2008; Deininger MW. Hematology Am Soc Hematol Educ Program. 2005;174-182. *Cytogenetic response is based on analysis of at least 20 metaphases. PCyR + CCyR = major cytogenetic response (MCyR).

18Deininger MW. Management of early stage disease. Hematology Am Soc Hematol Educ Program. 2005;:174-82.

National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology: chronic myelogenous leukemia. V.3.2008. http://www.nccn.org. Accessed 02/04/2008.

CML MONITORINGA Primer19Monitoring Disease Burden in CMLBone marrow metaphase karyotype The historical gold standard. Requires growing and dividing cells, hence marrow biopsy generally necessary in chronic phase CML patients. Advantage: well-validated as a surrogate marker of survival. Disadvantages: invasive procedure, operator-dependent interpretation. Ph chromosome not always distinguishable despite its presence. Poor sensitivity (~5%).

Cell Cycle

CentromereSister ChromatidsChromosomes are maximally condensed in metaphase of mitosis21-To remind you of the phases of the cell cycle, DNA replicated in S, resulting in sister chromatids, which are segregated to daughter cells in Mitosis; S and M are separated by two Gap phases G1 and G2- Interphase consists of G1, S, G2; during interphase, DNA/chromatin is uncoiled, spread out throughout the nucleus; txn/transln occurs. In Mitosis, chromatin condenses so you can see and identify individual chromosomes. Forrest et al, 2008; Bakshi et al, 2008; Image courtesy of Larry Beauregard, Jr., PhD.

46,XX,t(9;22)(q34;q11.2) a.k.a. the Philadelphia chromosomeThe Philadelphia Chromosome22Purpose of this & the following 3 slides are to note the proper use, advantages, and limitations of each assay used to diagnose CML

Dr. Beauregard can be reached by calling (207)-973-7357, or by e-mail at lbeauregard@emh.org

http://images.google.com/imgres?imgurl=http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/Ph1Karyotype.gif&imgrefurl=http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/C/CML.html&usg=__GbQY2sgxukeQYT6-TlkSH_yfPqw=&h=383&w=384&sz=29&hl=en&start=1&itbs=1&tbnid=o1n4zzzt_E2aNM:&tbnh=123&tbnw=123&prev=/images%3Fq%3Dcml%2Bkaryotype%26gbv%3D2%26hl%3Den22Monitoring Disease Burden in CMLBone marrow metaphase karyotype The historical gold standard. Requires growing and dividing cells, hence marrow biopsy generally necessary in chronic phase CML patients. Advantage: well-validated as a surrogate marker of survival. Disadvantages: invasive procedure, operator-dependent interpretation. Ph chromosome not always distinguishable despite its presence. Poor sensitivity (~5%).

Fluorescence in situ hybridization Performed on non-dividing (interphase) cells. Advantage: can be performed on peripheral blood. Disadvantages: Not validated with outcome, does not always correlate with metaphase karyotype. Relatively poor sensitivity (~2%).

Detecting Mutations: FISH

Example of FISH detecting a reciprocal chromosome translocationMonitoring Disease Burden in CMLBone marrow metaphase karyotype The historical gold standard. Requires growing and dividing cells, hence marrow biopsy generally necessary in chronic phase CML patients. Advantage: well-validated as a surrogate marker of survival. Disadvantages: invasive procedure, operator-dependent interpretation. Ph chromosome not always distinguishable despite its presence. Poor sensitivity (~5%).

Fluorescence in situ hybridization Performed on non-dividing (interphase) cells. Advantage: can be performed on peripheral blood. Disadvantages: Not validated with outcome, does not always correlate with metaphase karyotype. Relatively poor sensitivity (~2%).

BCR-ABL quantitative PCR Quantifies the BCR-ABL transcript level to the level of a housekeeping gene detected. Advantages: can be performed on peripheral blood. Highly sensitive (0.001%). Disadvantages: Not well-standardized. Results obtained from one laboratory cannot be compared with results from a different laboratory. May not detect abnormal fusions.Monitoring Disease Burden in CMLTimeDxCytogeneticsFISHRT-PCRTreatmentCML (log10)1-2 log reduction~ 5-6 log reductionMMR = 3 log

PCR: Polymerase Chain Reaction

IMATINIB-RESISTANT DISEASEHow is it defined?34Imatinib Resistance in Chronic Phase CML DefinitionsPrimary resistance: lack of an acceptable initial response Primary hematologic resistance rarePrimary cytogenetic resistance ~35% of patientslack of PCyR (35% Ph) by 3 monthslack of CCyR (0% Ph) by 12 - 18 months

35Imatinib Resistance in Chronic Phase CML DefinitionsPrimary resistance: lack of an acceptable initial response Primary hematologic resistance rarePrimary cytogenetic resistance ~35% of patientslack of PCyR (35% Ph) by 3 monthslack of CCyR (0% Ph) by 12 - 18 months

Secondary resistance: loss of an established initial response (relapse despite tx) Hematologic Relapse WBC >nl and increasing)Cytogenetic Relapse 30% increase in Ph+ metaphasesMolecular Relapse confirmed 1-log increase in BCR-ABL transcript level with lack/loss of MMR36Primary resistance is a risk factor for the development of secondary resistanceImatinib Resistance in Chronic Phase CML DefinitionsPrimary resistance: lack of an acceptable initial response Primary hematologic resistance rarePrimary cytogenetic resistance ~35% of patientslack of PCyR (35% Ph) by 3 monthslack of CCyR (0% Ph) by 12 - 18 months

Secondary resistance: loss of an established initial response (relapse despite tx) Hematologic Relapse WBC >nl and increasing)Cytogenetic Relapse 30% increase in Ph+ metaphasesMolecular Relapse confirmed 1-log increase in BCR-ABL transcript level with lack/loss of MMR37Imatinib Survival Without Accelerated Phase/Blast Crisis by Molecular Response: IRIS StudyDruker B et al. N Engl J Med. 2006;355:2408-2417. Time (months since randomization)n=54 98%Estimated rate at 60 months P 0.35-fold 48 83% Overall survival (OS) according to BCR-ABL reduction to 0.35-fold at 3 months 0.001This is the the same landmark analysis for overall survival.

The stratification yields a good discrimination with a five-year difference in survival of 83% in the high-risk group compared to 98% in the good-risk group.

44

Overall survival (OS) according to 10% BCR-ABLIS at 3 monthsBCR-ABLIS at 3 months n 5Y-OS p-value

10% 234 97% > 10% 67 90%n.s.Again, the 10% BCR-ABL landmark at 3 months results in a less good prediction and does not reach statistical significance.

45Wide variability in BCR-ABL transcript levels in untreated patientsBCR-ABLIS (%)

using GUS(CF=2.18)Patient #Median 33% Range 1-230Now, this is the key slide of my talk and it shows the distribution of baseline BCR-ABL transcript levels over the 301 patients investigated.

BCR-ABL was standardized according to the international scale using our lab-specific conversion factor of 2.18 for GUS as a reference gene.

As you can see BCR-ABL levels vary over a broad range from 1 to 230% with a median of 33%.46Imatinib: IRIS 8-Yr Update Shows 37% Have Unacceptable Outcome*Unacceptable outcome.Deininger M, et al. ASH 2009. Abstract 1126.CCyR, complete cytogenetic response.47CML monitoring simplifiedQuantitative BCR-ABL PCR at diagnosis and every three months thereafterAchievement of 10% BCR-ABL (IS) or PCyR after 3 months of imatinib is associated with superior survival in multiple studiesThe value of a 0.5 log reduction compared with the patients own baseline requires confirmation in other studies Bone marrow cytogenetics should be performed at diagnosis in all patients, and at three and/or 12 months in select cases thereafterAchievement of a complete cytogenetic response remains the minimum acceptable level of response on TKI therapyIdeally achieved within 12-18 months of TKI initiation

48Long-Term Adherence to Imatinib Is Critical for Achieving Molecular ResponseAdherence to imatinib tracked for 3 mos in 87 consecutive CML patients with CCyR using microelectronic monitoring devicesMarin D, et al. J Clin Oncol. 2010;28:2381-2388.MMRCMRProbability of MMR00.81.0Mos Since Start of Imatinib Therapy0.60.40.2061218243036424854606672P < .001Adherence > 90% (n = 64)Adherence 90% (n = 23)Probability of CMR00.81.0Mos Since Start of Imatinib Therapy0.60.40.2061218243036424854606672P = .002Adherence > 90% (n = 64)Adherence 90% (n = 23)CCyR, complete cytogenetic response; CML, chronic myeloid leukemia; CMR, complete molecular response; MMR, major molecular response.49IMATINIB-RESISTANT DISEASEWhat are its causes?50Clinical Resistance to Imatinib is Most Often Associated with Restoration of BCR-ABL Kinase Activity51WILD-TYPET315I MUTANT (MODEL)

ATP-binding pocket of T315I mutant BCR-ABLcannot accommodate imatinibstructural data provided by B. Nagar andJ. Kuriyan UC Berkeley (Gorre et al, Science, 293:876, 2001) 52E255K/VM244V M351TY253H/F

E279K F317LE355G/DF359C/V/D/I

H396R/PQ252H/RS417Y E459K/Q F486S E450G/Q M388L G250E/A/F D276GT277AL387F/MV379I A397PE453G/KT315I/NF311L/IV289AL298VL248V E281A L364I G383DE292Vx(Incomplete) map of BCR-ABL kinase domain mutations associated with clinical resistance to imatinibGorre et al, 2001; von Bubnoff et al, 2002; Branford et al, 2002; Hofmann et al, 2002; Roche-LEstienne et al, 2002; Shah et al, 2002; Hochhaus et al, 2002; Al-Ali et al, 2004PCACourtesy Tim Hughes53

MB13imatinib

MB14imatinibchemotherapy

BCR-ABL gene amplificationassociated with clinical imatinib resistanceGorre et al, Science, 293:876, 200154

Shah NP et al. Cancer Cell. 2002;2:117-125. Mutations thatdirectly affect imatinib bindingMutations that affect the conformation required to bind imatinibRole of Kinase Conformation in Imatinib ResistancePoint mutations in BCR-ABL kinase domain can destabilize the inactive conformationMolecular Mechanisms of Resistance to Imatinib ImplicationsBCR-ABL kinase inhibitors that are:

(1) more potent than imatinib and (2) have activity against imatinib-resistant kinase domain mutations

may be of significant therapeutic benefit to imatinib-resistant and -intolerant patients56Dasatinib Inhibits Growth of 14/15 Imatinib-Resistant BCR-ABL-Expressing Ba/F3 Cell Lines in vitroShah et al, Science, 2004Normalized cell number after 48 hours of drug exposureConcentration of dasatinib (nM)*00.20.40.60.811.200.52.552550T315IQ252HBa/F3Bcr-AblE255KM351TM244VG250EQ252RY253FY253HE255VF317LE355GF359VH396RF486ST315IParental Ba/F3 cells*Dasatinib is 300-400 more potent than imatinib in vitro57