Long-term toxicity of therapy for CLL

1. Long-term toxicity of therapy for CLL Mitchell R. Smith, M.D., Ph.D. Director of Lymphoid Malignancy Program Taussig Cancer Institute Cleveland Clinic Cleveland, OH

2. 1960-70s The Evolution of TreatmentOptions in CLL 1980s 1990s 2000s 2010s • Purine • Analogs • 80% • 10-20% Purine Analog + alkylator 85% 25% Novel Agents Chemo-immuno therapy 90% 40-50% • Alkylators • 50% • 5% ??? RR CR DESIRED Increase CR rate ENDPOINTS: Achieve MRD status More durable remissions

3. What we have heard so far • CLL is a disease of the immune system • CLL involves aberrant cell proliferation and cell death • BCR signaling is important target in CLL • (Apoptosis is important target in CLL) • p53 function important in CLL • CLL has a genetic component • Current initial therapy is based on chemotherapy + anti-CD20 antibody (BR/FCR) • Until we can cure CLL, goal is to prolong survival • Since survival is long, long term toxicity of our interventions is important consideration

4. CHEMOIMMUNOTHERAPY TOXICITY MYELOID Prolonged myelo-suppression infection bleeding Inability to tolerate subsequent therapy Therapy related myeloid neoplasia (t-MN) LYMPHOID Prolonged B- cell suppression hypogammaglobulinemia and infection Prolonged T- cell suppression “opportunistic” infections autoimmune disorders OTHER ORGANS FORTUNATELY NOT AN ISSUE

5. CAUSES OF DEATH IN CLL • “The most frequent causes of death are severe systemic infection (especially pneumonia and septicemia) [~50%], bleeding, and inanition with cachexia.” • Up-to-Date accessed 10/1/13 • Prolymphocytic transformation [5-10%] clonal evolution/selection? • Richter’s transformation [1-2%] • 2nd malignancy – incidence and  outcome

6. INFECTION IN CLL

7. INFECTION IN CLL Therapeutic Interventions: VACCINATIONS PNEUMOVAX, FLU, NOT ZOSTAVAX ANTI-MICROBIALS – bacterial, viral, fungal IVIG MYELOID GROWTH FACTORS

8. BLEEDING IN CLL:THROMBOCYTOPENIA • DISEASE: • BONE MARROW INFILTRATION • HYPERSPLENISM • AUTO-IMMUNE (ITP) • THERAPY • MYELOSUPPRESSIVE CHEMOTHERAPY • MYELODYSPLASIA • EFFECTS OF NOVEL AGENTS?

9. TRANSFORMATION IN CLL • Prolymphocytic transformation clonal evolution/selection? Rx could prevent or cause? • Richter’s transformation if same clone, as for PLL above if different clone, as another 2nd malignancy • 2nd malignancy – incidence and  outcome Immune dysfunction/surveillance? Chemotherapy induced?

10. What are the long-term concerns about therapy-related toxicity in CLL? • Neutropenia • B Cell Dysfunction (Hypogammaglobulinemia) • T Cell Dysfunction • Thrombocytopenia • Infection • Transformation (Richter’s or Prolymphocytic) • Second neoplasm • Therapy-related Myeloid Neoplasia (t-MN) • Inability to collect stem cells

11. ACUTE TOXICITY: FCR VS BRGrade 3 or 4 (% of patients) Fcr German CLL8 Br German CLL sg phase 2 Neutropenia34% Thrombocytopenia 7% Infection25% AIHA1% Neutropenia 20% Thrombocytopenia 22% Infection 8% AIHA (onset prior to Rx)2%

12. Prolonged CytopeniasStrati P, et al MDACC Cancer 2013 • 207 patients with CR, CRi, nPR after FCR as initial therapy for CLL

13. F vs FC as Initial Therapy of CLL: E2997 TRIAL DESIGN Fludarabine 25 mg/m2 IV 1-5q4w × 6 (n=137) RANDOMIZE ASSESS Pts with previously untreated CLL requiring therapy (N=278) Cyclophosphamide 600 mg/m2 IV 1 Fludarabine 20 mg/m2 IV 1-5*q4w × 6 (n=141) ASSESS *Patients in the FC arm received filgrastim 5 mg/kg SC and antiviral prophylaxis All patients received allopurinol cycle 1 and PCP prophylaxis Flinn et al. J Clin Oncol 2007; 25:793-798

14. F vs FC as Initial Therapy of CLL:Short-term Bone Marrow Toxicity * % of cycles Flinn I W et al. JCO 2007;25:793-798

15. F vs FC as Initial Therapy of CLL: Long term Bone Marrow Toxicity • HYPOTHESES: Short term bone marrow toxicity of FC indicates additive DNA damage that will be reflected in long term toxicity Specifically, therapy related myelodysplasia (MDS) or acute myeloid leukemia (AML) Collectively termed: therapy-related myeloid neoplasia (t-MN) • METHODS: t-MN cases ascertained by review of E2997 case report forms and by required AdEERS reporting

16. F vs FC Initial Therapy of CLL Results: t-MN Incidence • E2997 enrolled 278 patients • FC 141 • F 137 • Median follow-up: 6.4 years • Cases of t-MN: 13 • crude incidence 4.7% • Median age at study entry: • for t-MN 60 • for entire population 61

17. F vs FC Initial Therapy of CLL Results: t-MN Incidence • Median time from CLL therapy to t-MN: • 5 yrs (0.7-8 yrs) not different between FC and F • 10 of 13 t-MN patients received 6 cycles of therapy • Cytogenetics of t-MN available in 12 • 10 had abnormal 5 and/or 7 • 8 of these had complex cytogenetics • 1 had 45 XY, -7, del(12)(p11.2) • 1 had 45 XY, -7 • 1 was 46 XX, +1, der(1;15) • 1 was 47 XY +add(12)(q13),t(14;19)(q32;q13) • c/w residual CLL

18. Cumulative Incidence Method • Second malignancies reportable per NCI for all patients • Includes SMNs occurring after subsequent therapy • Death competes with ability to detect second malignancy • Competing risk methods identify times to: • t-MN • Competing risk (death) • Censoring (alive without t-MN)

19. Risk of t-MN with F vs FC Initial Therapy of CLL: Results

20. Risk of t-MN with F vs FC Initial Therapy of CLL: Results

21. Risk of t-MN with F vs FC Initial Therapy of CLL: Possible relation to CLL IgVH Gene Mutation Status

22. Risk of t-MN with F vs FC Initial Therapy of CLL: Possible relation to CLL IgVH Gene Mutation Status

23. Risk of t-MN with F vs FC Initial Therapy of CLL: CONCLUSIONS • Incidence of t-MN increased after FC • Median time to t-MN 5 years • Longer follow-up may reveal ongoing risk (or not?) • Cytogenetics/FISH of t-MN suggests DNA damage • No evidence of antecedent abnormalities on CLL FISH • Consistent with prior F-chlorambucil and FCR data • FC yields longer PFS, so most t-MN occur in absence of additional chemotherapy • IgVHeffect requires confirmation • t-MN needs consideration in choosing CLL therapy

24. Risk of t-MN with F ± C as Initial CLL Therapy

25. Risk Factors for t-MN • Fludarabine combination therapy • Additional courses of DNA-damaging agents • Higher Age? in MDACC data • Use of myeloid growth factors? • Not much “signal” yet for bendamustine Not looked for enough? More single agent use? Less persistent DNA damage? Less immunosuppressive?

26. CHARACTERISTICS OF t-MN • Earlier onset if persistent cytopenia, but can arise from recovered marrow as well* • May be difficult to differentiate from hypoplasia • Usually abnormal chromosome 5 and/or 7, not 11q23 • Typical poor outcomes *Zhou Y et al Modern Pathology 2012

27. RISK OF PLL and RICHTER’S TRANSFORMATION • Variable incidence and variable definition • PLL usually clonally related, but evolved • Richter’s Syndrome • Clonally related 50-70% of cases, likely “2nd hit” or selection Not likely to be Rx induced • Clonally unrelated 20-50%, some of these EBV+ Hypothesize these may be due to immunosuppression and could be influenced by therapy • CALGB 9011 analysis • Solh M et al Leuk Lymphoma 2013

28. “SECOND” SOLID NEOPLASMS • Increased incidence in CLL (Morton LM JCO 2010) • Worse outcomes in patients with CLL • Theoretically increasing immune suppression might predispose • No data these are fludarabine-induced (Cheson et al JCO 1999) • Reports of rapid growth early after Rx

29. CONCLUSIONS • Long term toxicity of therapy for CLL is primarily marrow and immune suppression • Main concerns are: • prolonged cytopenias and infection • t-MN • Fludarabine combinations appear to confer higher risk • “Novel” agents are expected to reduce these risks, but long-term follow-up is prudent