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Kathy D. Miller, MD Associate Professor and Sheila D. Ward Scholar Indiana University Melvin and Bren Simon Cancer Center Indianapolis, IN. Clinical Updates. Advances in Targeted Therapies for Breast Cancer A Report From SABCS 2009. Discussion Topics. HER2 positive disease
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Kathy D. Miller, MD Associate Professor and Sheila D. Ward Scholar Indiana University Melvin and Bren Simon Cancer Center Indianapolis, IN Clinical Updates Advances in Targeted Therapies for Breast Cancer A Report From SABCS 2009
Discussion Topics • HER2 positive disease • Growing number of options • Angiogenesis • Bevacizumab questions answered and rephrased • Small molecule success and disappointment
HER2: What We Knew Before SABCS • Trastuzumab • Active as single agent and adds to chemo/HRT • Effective with chemo beyond PD • Adds to lapatinib monotherapy (ORR, PFS) • Lapatinib • Active as single agent and adds to chemo/HRT • Effective with chemo after PD on trastuzumab • MULTIPLE new agents in development
Case 1 • 54 year old woman with newly diagnosed stage II breast cancer s/p lumpectomy and axillary dissection • Primary tumor 1.9 cm • Involves 1 of 14 LN (1/2 SN, 0/12 additional LN) • Grade III • ER+ 15%, PR- • HER2 2+ by IHC (intense staining in 20% of cells) • FISH equivocal with ratio 2.15 • Do you recommend adjuvant trastuzumab?
Background • In 2007, ASCO/CAP recommended new guidelines to define HER2 positivity by both IHC 3+* and FISH+** • 3+ IHC: Uniform intense membrane staining of > 30% of invasive tumor cells • FISH+: HER2/CEP17 ratio > 2.2 • Original HER2 eligibility criteria in the pivotal N9831 Phase III Adjuvant HER2 Trial • 3+ IHC: Uniform intense membrane staining of > 10% of invasive tumor cells • FISH+: HER2/CEP 17 ratio ≥ 2.0 HerceptTest DAKO, Carpenteria, CA; FISH: PathVysion, Abbott Molecular; Masood S et al. Ann Clin Lab Sci 1998;28(4):215-223; Perez EA et al. SABCS 2009 #701
N9831 DFS Based on Original Criteria: HER2 Non-positive* vs. HER2+** * HER2 Non-positive (IHC ≤ 10 and FISH Ratio < 2.0) ** HER2+ (IHC > 10 or FISH Ratio ≥ 2.0) Perez EA et al. SABCS 2009 #701
N9831 DFS Based on 2007 ASCO/CAP: HER2 Non-positive* vs. HER2+** * HER2 Non-positive (IHC ≤ 30 and FISH Ratio ≤ 2.2) ** HER2+ (IHC >30 or FISH Ratio > 2.2) Perez EA et al. SABCS 2009 #701
Conclusions • A small percentage (by IHC:3.7%, FISH 1.4%, both:1.7%) of N9831 pts did not meet ASCO/CAP 2007 HER2 positivity guidelines when applied retrospectively • Trastuzumab effect appeared similar for HER2+ pts regardless of ASCO/CAP or originally used FDA-approved guidelines • Data support determining eligibility for trastuzumab based on the original definition of HER2 positivity (IHC 3+, >10% staining; FISH ratio>2.0). Perez EA et al. SABCS 2009 #701
Case 1 • 54 year old woman with newly diagnosed stage II breast cancer s/p lumpectomy and axillary dissection • Primary tumor 1.9 cm • Involves 1 of 14 LN (1/2 SN, 0/12 additional LN) • Grade III • ER+ 15%, PR- • HER2 2+ by IHC (intense staining in 20% of cells) • FISH equivocal with ratio 2.15 • Do you recommend adjuvant trastuzumab? • YES
BCIRG 006 NCCTG N9831 IHC orFISH FISH NSABP B-31 HERA Observation IHC orFISH IHC orFISH AC P D DCarbo Standard Trastuzumab 1 year Adjuvant Trastuzumab 1 v 2 years IHC, immunohistochemistry;FISH, fluorescence in situ hybridisation
BCIRG 006 DFS Events First / Second / Third Planned Efficacy Analyses (cutoff dates: 30June2005 / 01Nov2006 / 16Oct2009) • Median follow-up time = 23/36/65 months • 322/462/656 DFS events (42% additional events) • Breast cancer relapse • Second primary malignancy • Death • 84/185/348 deaths (88% additional deaths)
Current BCIRG 006Disease-Free Survival – 3rd Planned Analysis
Efficacy Analysis *Patients eligible for crossover censored Data frozen on 11/3/2009 Control (A)* vs Sequential (B)* AC → T → H AC → T Perez EA et al, SABCS 2009
Alive anddisease free (%) 100 AC → T → H (164 events) 90 85.2% 80.1% 80 79.7% 70 71.9% AC → T (222 events) Log rank P=0.0005 60 50 735 675 624 586 513 1097 No. at risk 728 643 581 529 1087 447 40 0 1 2 3 4 5 Years from randomization Control vs Sequential Perez EA et al, SABCS 2009
Efficacy Analysis *Censoring based on temp closure of C,and eligibility for crossover Data frozen on 11/3/2009 Sequential (B)* vs Concurrent (C) AC → T+H → H AC → T → H N9831 Perez EA et al, SABCS 2009
Sequential vs Concurrent 1st Interim Analysis • At 50% of planned number of events (312 events) • 1,903 pts, median follow-up: 5.3 yr • 75% of pts followed for 5 yr • DFS may differ with respect to the timing of trastuzumab’s addition to AC → T • Log rank P=0.019 (HR 0.77; 95% CI 0.61-0.96) • Not crossing the boundary for statistical significance, pre-set at 0.00116 Perez EA et al, SABCS 2009
Alive anddisease free (%) Sequentialvs Concurrent AC →T+ H → H (138 events) 100 89.1% 90 84.2% 85.7% 80 79.8% AC → T → H (174 events) 70 Logrank p=0.0190 60 50 949 837 788 740 676 456 No. at risk 830 766 705 954 641 418 40 0 1 2 3 4 5 Years from randomization Perez EA et al, SABCS 2009
Conclusions • DFS is significantly improved with the additionof 52 wks of trastuzumab to AC T • There is a statistically significant 33% reduction in the risk of an event with the sequential addition of trastuzumab following AC T • 5 yr DFS: 72% vs. 80% • There is a strong trend for a 25% reductionin the risk of an event with starting trastuzumab concurrently with taxane relative to sequentially • 5 yr DFS: 80% vs. 84% Perez EA et al, SABCS 2009
Median follow-up HERA 1 year Combined analysis 2 years 2 years BCIRG 006 AC DH 2 years BCIRG 006 DCarboH 3 years FinHER VH / DH CEF FavorsTrastuzumab Favors noTrastuzumab 0 1 2 HR Trastuzumab DFS Piccart-Gebhart et al 2005; Romond et al 2005;Slamon et al 2005; Joensuu et al 2005
Adjuvant Trastuzumab • Test everyone for HER2, inquire about testing quality and look carefully at ‘equivocal’ results • Most important message -> Give Trastuzumab! • Either TCH or AC>TH supported by data • Differences between regimens modest • Slightly more recurrence with TCH balanced by increased cardiac and long-term marrow toxicity with AC>TH • Give concurrently with chemo unless there is a compelling reason not to
Case 2 • 74 year old presents with 5 cm primary breast mass with associated axillary adenopathy. • ER-, PR-, HER2 3+ by IHC (FISH ratio 8.9) • Staging finds several liver lesions, largest 2.2 cm • Biopsy of liver lesion confirms MBC, HER2+ • LFTs normal • LVEF 62% • She refuses chemotherapy but will consider other options, family supports her wishes • What would you recommend?
Lapatinib Trastuzumab Pathway ActivationHER Ligands
Lapatinib + Trastuzumab Lapatinib 1500 mg PO QD (n = 148) EGF104900 Primary endpoint: PFS Secondary endpoints: OS ORR CBR Optional crossover to trastuzumab arm if PD after 4 wks (n = 77) Heavily pretreated patients with HER2-positive MBC and progression on trastuzumab (N = 296) Lapatinib 1000 mg PO QD + Trastuzumab 4 mg/kg loading dose, then 2 mg/kg IV wkly (n = 148) Stratified by visceral disease and hormone receptor status PO, orally; QD, once daily. Blackwell K, et al. SABCS 2009 # 61.
Lapatinib + Trastuzumab 52% of patients crossed over from single-agent lapatinib to combination therapy on progression. Blackwell K, et al. SABCS 2009 # 61.
Lapatinib + Trastuzumab Safety Update • Most AEs reported in ≥ 10% of patients were grade 1/2 • Diarrhea was the only grade 3/4 AE reported in ≥ 5% of patients • 8% of patients receiving lapatinib plus trastuzumab vs 7% receiving lapatinib alone • 1 fatal cardiac event in combination arm * Defined as grade ≥ 3 LV dysfunction, LVEF decrease ≥ 20% from baseline and below lower limit of normal defined by institution. Blackwell K, et al. SABCS 2009 # 61.
Lapatinib + Trastuzumab • Lapatinib + trastuzumab associated with 26% improvement in OS vs lapatinib alone • Significant survival benefit despite 52% crossover • Supports combination arm of ALTTO • Lapatinib plus trastuzumab well tolerated • AEs comparable to lapatinib alone • Offers possible options for heavily pretreated patients who progress on trastuzumab Blackwell K, et al. SABCS 2009 # 61.
T-DM1 • T-DM1, an antibody-drug conjugate, combines biologic effect of trastuzumab against HER2-expressing cells with highly potent antimicrotubule agent DM1 • MOA likely involves receptor-mediated internalization of T-DM1 after binding to HER2, resulting in intracellular release of DM1 Austin CD et al. Mol Biol Cell. 2004;15:5268-5282.
T-DM1 Monotherapy • Multicenter, single arm (N=110) • Primary endpoint – ORR by IRF at 24 weeks • Eligibility • Prior anthracycline, taxane, capecitabine, trastuzumab, lapatinib • Active disease progression on last therapy • LVEF 50% or better Krop I, et al. SABCS 2009.#5090.
T-DM1 Monotherapy • ORR (by independent review) 32.7% • Clinical benefit rate (by independent review) 44.5% • Median PFS 7.3 months • T-DM1 well tolerated • Thrombocytopenia • Offers a very real option for additional therapy for HER2+ patients Krop I, et al. SABCS 2009 #5090.
P<0.0001 Response Rates for Novel HER2-Targeting Agents After Progression on Trastuzumab Modi et al, ASCO 2008; Gelmon et al, ASCO 2008; Swaby et al, ASCO 2009; Burris et al, ESMO 2009.
Topics • HER2 positive disease • Growing number of options • Angiogenesis • Bevacizumab questions answered and rephrased • Small molecule success and disappointment
Angiogenesis • Angiogenesis is important for tumor growth • Highly regulated, multiple redundant pathways • VEGF among the most potent and frequently overexpressed • Bevacizumab • Modest activity as monotherapy • Disappointing results in initial randomized trial • E2100, then AVADO and RIBBON-1 • Now RIBBON-2
RANDOMI ZE Paclitaxel + Bevacizumab • 28-day cycle: • Paclitaxel 90 mg/m2 D1, 8 and 15 • Bevacizumab 10 mg/kg D1 and 15 Paclitaxel • Stratify: • DFI < 24 mos. vs. > 24 mos. • < 3 vs. > 3 metastatic sites • Adjuvant chemotherapy: yes vs. no • ER+ vs. ER- vs. ER unknown E2100 Miller K, et al. N Engl J Med. 2007;357:2666-2676
Primary endpoint: progression-free survival Secondary endpoints: overall response rate, duration of response, time to treatment failure, overall survival, safety, quality of life *Docetaxel was administered for a maximum of nine cycles, but earlier discontinuation was permitted Treat withplacebo/bevacizumabto diseaseprogression All patientsgiven optionto receive bevacizumabwith 2nd-linechemotherapy Docetaxel* 100mg/m2+ placebo q3w • 1st-line locally recurrent • or mBC (n=705) • Stratification factors: • region • prior taxane/time to relapse since adjuvant chemo • measurable disease • hormone receptor status Docetaxel* + bevacizumab 7.5mg/kg q3w Docetaxel* + bevacizumab 15mg/kg q3w AVADO Miles D, et al. J Clin Oncol. 2008;26(18S). LBA 1011.
Previously untreated MBC • (n=1,237) • Stratification Factors: • Disease-free interval • Previous adjuvant chemotherapy • Number of metastatic sites • Cape, T or Anthra CHOICE OF CHEMO BY INVESTIGATOR Chemo +bevacizumabq3w Treat until PD Optional2nd-line Chemo+ bevacizumab RANDOMIZE 2:1 Chemo +placeboq3w RIBBON-1 Capecitabine or TaxaneorAnthracycline • Capecitabine (1000 mg/m2 BID x 14d) • Taxane (docetaxel or protein-bound paclitaxel) • Anthracycline-based chemotherapy (AC, EC, FAC, FEC) • Placebo or bevacizumab (15 mg/kg) Robert et al, ASCO 2009 #1005
Study Design 1Miller K, et al. N Engl J Med. 2007;357:2666-2676; 2Miles D, et al. J Clin Oncol. 2008;26(18S). LBA 1011. 39
Patient Population 1Miller K, et al. N Engl J Med. 2007;357:2666-2676; 2Miles D, et al. J Clin Oncol. 2008;26(18S). LBA 1011.
Efficacy Relative increase in RR 20-50%
Case 3 • 63 year old with metastatic breast cancer consults you for advice on additional therapy • Initial diagnosis 6 years ago, adjuvant AC x 4 cycles followed by AI for stage I disease (T2.1 cm, LN-, G2, ER+, PR-, HER2-) • Metastatic disease identified with bone invovlement and mediastinal and SC adneopathy ~28 months ago • Initially treated with fulvestrant > PR lasting 12 months • Tamoxifen > SD lasting 6 months • Exemestane > PD after 2 months • Capecitabine > PR lasting 8 months, now with PD
Case 3 • Currently has minimally symptomatic bone involvement (does not require narcotics) with asymptomatic mediastinal nodes and new pulmonary nodules (largest 1.6 cm) • PS = 1 • Local oncologist has recommended taxane based therapy • Would you add bevacizumab?
Second-line Chemotherapy of choice† HER (-) Bevacizumab 10 mg/kg q2w (Bevacizumab 15 mg/kg q3w) Randomize 2:1 Chemotherapy of choice† Placebo †Docetaxel, paclitaxel (qw or q3w), nab-paclitaxel, gemcitabine, vinorelbine, or capecitabine. Ribbon 2 National Cancer Institute. Clinical Trials (PDQ). Available at: http://www.cancer.gov/search/clinical_trials/.
Key Eligibility Criteria • One prior cytotoxic treatment for MBC • ECOG performance status (PS) 0 or 1 • HER2-negative or HER2 status unknown • No prior therapy with bevacizumab or other VEGF pathway- target therapy
Primary Endpoint of PFS(ITT Population) Brufsky et al, SABCS 2009 #42
Cohort-Specific Analyses of PFS(ITT Population) Brufsky et al, SABCS 2009 #42
What We’ve Learned • Bevacizumab is an important component of initial chemotherapy for metastatic HER2- breast cancer • Increases RR • Prolongs PFS • Adds to second-line chemo in patients who didn’t get bevacizumab with initial chemo • Toxicity differs among reported regimens • Bevacizumab associated toxicity consistent
Remaining Questions • Combine with anti-HER2 and hormonal therapies • Optimal duration of therapy • Why have we failed to demonstrate a difference in OS?
In Search of OS • There is no difference • Subsequent therapy obscures benefit of 1st line therapy • Reported trials individually underpowered • Amenable to meta-analysis (see ASCO 2010) • Resistance to bevacizumab = more aggressive disease • Rapid regrowth of vasculature after stopping bevacizumab