1 The Role of Pathologic Complete Response (pcr) as a Surrogate Marker for Outcomes in Breast Cancer: Where Are We Now? Terry Mamounas, M.D., M.P.H., F.A.C.S. Medical Director, Comprehensive Breast Program UF Health Cancer Center at Orlando Health Professor of Surgery, University of Central Florida College of Medicine Clinical Professor of Clinical Sciences, Florida State University College of Medicine
Clinical Rationale for Neoadjuvant Chemotherapy Neoadjuvant chemotherapy is the standard of care for patients with locally advanced breast cancer A reasonable alternative to adjuvant chemotherapy for those with large operable disease Several randomized clinical trials have shown no significant differences in outcomes between neoadjuvant and adjuvant chemotherapy
Pathologic Complete Response (pcr): A Surrogate Endpoint for NC Efficacy Patients who achieve pcr following NC have significantly better outcomes than those who do not As a result pcr has become a surrogate endpoint for NC efficacy Recently, the FDA identified pcr as an endpoint that can be utilized for accelerated approval of new agents for the neoadjuvant treatment of breast cancer
Effect of pcr on Overall Survival NSABP B-18 NSABP B-27 Rastogi et al. J Clin Oncol 2008
CTNeoBC Meta-Analysis: Association of pcr with EFS and OS HR=0.48, P* < 0.001 HR=0.36, P* < 0.001 pcr=ypt0/is ypn0 * Nominal p-value Cortazar P, et al: SABCS 2012
CTNeoBC Meta-Analysis: Various Definitions of pcr No evidence of tumor in the breast and negative axillary nodes (ypt0 ypn0) No tumor or in situ tumor only in the breast and negative axillary nodes (ypt0/is ypn0) (Preferred FDA definition) No tumor/in situ tumor only in the breast irrespective of axillary nodal status (ypt0/is) Cortazar P, et al: SABCS 2012
Event-free Probability 0.0 0.2 0.4 0.6 0.8 1.0 Survival Probability 0.0 0.2 0.4 0.6 0.8 1.0 CTNeoBC Meta-Analysis: Which pcr Definition is Best Associated with Long Term Outcome? Event-free Survival Overall Survival ypt0 ypn0 n 1554 ypt0/is ypn0 n 2131 ypt0/is n 2598 pcr vs. no pcr HR= 0.44 pcr vs. no pcr HR= 0.48 pcr vs. no pcr HR= 0.60 ypt0 ypn0 n 1554 ypt0/is ypn0 n 2131 ypt0/is n 2598 pcr vs. no pcr HR= 0.36 pcr vs. no pcr HR= 0.36 pcr vs. no pcr HR= 0.51 0 50 100 150 200 Months since Randomization 0 50 100 150 200 Months since Randomization
Percent with pcr CTNeoBC Meta Analysis: pcr Rates by Tumor Subtype 50 40 30 20 10 _ HR+/HER2- HR+/HER2+ HR-/HER2+ HR-/HER2- Grade 1,2 Grade 3 No Tras Yes Tras No Tras Yes Tras Cortazar P, et al: SABCS 2012
In which Breast Cancer Subtypes Does pcr Associate with Long Term Outcome?
CTNeoBC Meta-Analysis: Association of pcr with EFS in HR+/HER2- Subtype
CTNeoBC Meta-Analysis: Association of pcr with EFS in HER2+ Subtype
CTNeoBC Meta-Analysis: Association of pcr with EFS with/ without Trastuzumab
CTNeoBC Meta-Analysis: Association of pcr with EFS in HR-/HER2- Subtype
What Magnitude of pcr Improvement in a Randomized Trial Will Predict Long Term Clinical Benefit (EFS and OS Improvement)?
Perfect Scenario Example Correlation Between Change in pcr and Improvement in EFS (Simulated Data)
CTNeoBC Meta-Analysis: Magnitude of Improvement in pcr Rate Did Not Predict EFS and OS Effect
CTNeoBC Meta-Analysis: Possible Reasons for Lack of Correlation Between Improvement in pcr Rates and EFS and OS Effect Low pcr rates Heterogeneity of the population Lack of targeted therapies (except in the NOAH trial) Larger pcr differences between treatment arms are needed to translate into long-term outcome and may vary according to breast cancer subtype
NSABP B-27 Schema Operable Breast Cancer (2411 pts) Randomization AC x 4 Tam X 5 Yrs AC x 4 Tam X 5 Yrs AC x 4 Tam X 5 Yrs Surgery Docetaxel x 4 Surgery Surgery Docetaxel x 4
NSABP B-27:Pathologic Response in Breast and Axillary Nodes pcr in Breast Positive Nodes 30 20 10 0 No Tumor P < 0.001 9.8% 13.7% 3.9% AC (1,492 pts) Non-Invasive 25.6% 18.7% 6.9% AC Docetaxel (718 pts) % 80 60 40 20 0 49 AC P < 0.01 41 AC Docetaxel Bear H, et al: J Clin Oncol, 2003
% Disease-free NSABP B-27: Disease-Free Survival 100 90 80 70 60 50 40 TRT N Events AC 801 264 AC T S 803 239 HR=0.86 p=0.10 AC S T 799 244 HR=0.91 p=0.27 0 1 2 3 4 5 Years after Surgery Bear H et al: J Clin Oncol 2006
pcr Rates and Adjuvant Chemotherapy Efficacy 60% 50% 40% 30% 20% Sign. in DFS,OS Sign. in DFS,OS 25-30% Sign. in DFS,OS 40-45% HER2+??? DFS, OS 50-60% 50-55% HER2+ TNBC 10% 0 7-8% CMFbased 15% Anthrabased Anthra/ Taxanebased Chemo + Traz based Chemo + Dual Anti-HER2 based Anthra/ Taxane- Based + Carbo
Neo-ALTTOStudy Design Invasive operable HER2+ BC T > 2 cm (inflammatory BC excluded) LVEF 50% N=450 Stratification: T 5 cm vs. T > 5 cm ER or PgR + vs. ER & PgR N 0-1 vs. N 2 Conservative surgery or not R A N D O M I Z E 6 wks lapatinib paclitaxel trastuzumab paclitaxel lapatinib trastuzumab paclitaxel S U R G E R Y F E C lapatinib trastuzumab lapatinib trastuzumab + 12 wks 34 weeks 52 weeks of anti-her2 therapy X 3
NeoALTTO Efficacy - pcr and tpcr L: lapatinib; T: trastuzumab; L+T: lapatinib plus trastuzumab pcr pathologic complete response
Design 1: Sequential anti Her2 Rx post chemo N=4602 ALTTO Trial Design 2: Concurrent anti Her2 Rx post anthra N=3337 First interim analysis Aug 11; L v T crossed futility boundaries
ALTTO: Changed Analysis Plan (N=6281) P < 0.025 for DFS statistical significance Piccart, M: ASCO 2014
ALTTO: Disease-Free Survival 100 90 80 88% 86% 70 L+T v T HR.84 P=0.048 60 Median Follow Up: 4.5 yrs 50 0 1 2 3 4 5 Piccart, M: ASCO 2014
NSABP B-41: Neoadjuvant Study with Lapatinib vs. Trastuzumab vs. Combo 27 Tissue for Biomarkers Tissue for Biomarkers Operable Breast Cancer HER-2 neu Positive R AC TH AC TL AC THL S U R G E R Y Endpoints: pcr, cardiac events, DFS, OS Trastuzumab for a total of 1 year Accrual: 529 pts
NSABP B-41: pcr Breast and Nodes (ypto/isypn0) P=0.056 P=0.78
NeoSphere Primary Outcome Measure: pcr* 100% 80% 60% 40% 20% 0% P = 0.014 P = 0.019 P = 0.003 46% 29% 17% 24% pcr TH n = 107 THP n = 107 HP n = 107 TP n = 96 *Pathologic complete response (pcr) rate defined as the absence of invasive cancer in the breast at the time of surgery. T = docetaxel; H = trastuzumab, P = pertuzumab. Gianni L et al. Lancet. 2012;13:25-32.
Pathologic complete response (%) TRYPHAENA Pathologic Complete Response 100 90 80 70 60 ypt0/is 50 40 30 61.6 57.3 66.2 20 10 0 FEC+H+P x3 T+H+P x3 (n = 73) FEC x3 T+H+P x3 (n = 75) TCH+P x6 (n = 77) FEC, 5-fluorouracil, epirubicin, cyclophosphamide; H, trastuzumab; P, pertuzumab; T, docetaxel; TCH, docetaxel/carboplatin/trastuzumab Schneeweiss A, et al: San Antonio 2011
TRYPHAENA: Pathologic Complete Response by HR-Status Pathologic complete response (%) ER- and PR-negative ypt0/is ER- and/or PR-positive 79.4 83.8 65.0 46.2 48.6 50.0 FEC+H+P x3 T+H+P x3 (n = 73) FEC x3 T+H+P x3 (n = 75) TCH+P x6 (n = 77) ER, estrogen receptor; FEC, 5-fluorouracil, epirubicin, cyclophosphamide; H, trastuzumab; P, pertuzumab; PR, progesterone receptor; T, docetaxel; TCH, docetaxel/carboplatin/trastuzumab Schneeweiss A, et al: San Antonio 2011
% Event-Free B-31/N9831 Joint Analysis Disease-Free Survival ER and/or PR Positive ER and PR Negative AC P AC P AC P+H AC P+H N Events xx% xx% AC P AC P+H AC P+H AC P N Events xx% xx% HR: 0.61 (95%CI: 0.51-0.72) HR: 0.62 (95%CI: 0.52-0.73) Years from Randomization No. at risk 1110 911 211 1105 762 151 917 700 139 911 566 104 Romond E et al: San Antonio 2012
How Do Utilize pcr to Maximize the Clinical Impact Of NC? Use pcr as a surrogate endpoint for long-term outcome (potential pathway for new drug approval) Identify better predictors of pcr: Baseline Early During treatment Use primary tumor response as a guide for tailoring systemic therapy and loco-regional therapy
Clinical and Pathologic Response to NC as a Guide for Tailoring Systemic Rx
Using Clinical and Path Response to NC as a Guide of Further Systemic Rx Development of multiple active drugs or regimens has lead to the following testable hypotheses: Achievement of pcr with more active regimens will continue to correlate with improved outcome Tumors that do not respond to the original neoadjuvant regimen may respond other active non-cross resistant regimens used either as neoadjuvant or post-neoadjuvant therapy (i.e. resistance is regimen- or drug-specific)
Sequential Docetaxel After Anthracycline-Based Neoadjuvant Chemotherapy: Aberdeen Trial First Phase Second Phase Response ITT All Patients 55 pts 4 cycles of Docetaxel cresp. presp. 47% 2% N = 162 4 cycles of CVAP T 2 (> 3cm), T 3, T 4, T x N 2 R A N D O M I Z E 4 cycles of Docetaxel 52 pts 4 cycles of CVAP 85% 31% p=0.001 p=0.04 64% 15% 52 pts Smith IC: J Clin Oncol; 2002
In Vivo Chemosensitivity-Adapted Neoadjuvant Chemotherapy: the GEPAR-TRIO Trial Sonography N=2072 Core biopsy: uni/bilateral ct2-4a-d cn0-3 size 2 cm* *low risk patients were excluded (T2 + ER/PR pos. + cno + G1/2 + > 35 yrs) Von Minckwitz G et al, SABCS 2011 NC CR/ PR R R NX von Minckwitz et al, JNCI 100: 542, 2008 von Minckwitz et al. JNCI 100; 552, 2008 TACx6 Conventional arms TACx6 TACx8 Responseguided arms
Short Term Efficacy (pcr = ypt0 ypn0) 30% Responders N=1344 P=0.27 Non-Responders N=604 P=0.73 20% 10% 21.0 23.5 0 TACx6 TACx8 5.3 TACx6 6.0 TAC-NX Von Minckwitz G et al, SABCS 2011 von Minckwitz et al, JNCI 100: 542, 2008 von Minckwitz et al. JNCI 100; 552, 2008
DFS and OS after Conventional (TACx6) vs. Response-guided (TACx8/TAC-NX) Treatment Median follow up 62 months Von Minckwitz G et al, J Clin Oncol 2013
DFS after TACx6 vs. TACx8 in Responding Patients Von Minckwitz G et al, J Clin Oncol 2013
DFS after TACx6 vs. TAC-NX in Non-Responding Patients Von Minckwitz G et al, J Clin Oncol 2013
GEPAR-TRIO: pcr Rates by Subtype 40 35 30 pcr (%) 25 20 15 10 5 0 Luminal A (N=572) Luminal B (HER2-) Luminal B (HER2+) HER2+ (nonluminal) Triple-negative (N=211) (N=281) (N=178) N=362) HR+, HER2-, G1/2 HR+, HER2-, G3 HR+, HER2+ HR-, HER2+ HR-, HER2- Von Minckwitz G et al, J Clin Oncol 2013
DFS in Luminal A Tumors by pcr by Treatment Von Minckwitz G et al, J Clin Oncol 2013
DFS in Luminal B (HER2-) by pcr by Treatment Von Minckwitz G et al, J Clin Oncol 2013
DFS in Luminal B (HER2+) Tumors by pcr by Treatment Von Minckwitz G et al, J Clin Oncol 2013
DFS in HER2+(non-luminal) Tumors by pcr by Treatment Von Minckwitz G et al, J Clin Oncol 2013
DFS in Triple Negative Tumors by pcr by Treatment Von Minckwitz G et al, J Clin Oncol 2013
GeparTrio: Conclusions Interim response-guided (longer or sequential) neoadjuvant chemotherapy improved survival Treatment effects on survival derived from luminal-type tumors This treatment effect could not be predicted by pcr as these tumors have lower pcr rates and their prognosis does not depend on pcr Patients with HER2+ or triple-negative tumors did not benefit from response-guided treatment pcr is highly prognostic in these subgroups Lack of treatment effect on pcr rate corresponds to lack of long term treatment effect Von Minckwitz G et al, J Clin Oncol 2013
Post-Neoadjuvant Trial Setting Is Ideal for Evaluating New Agents Enroll only high risk patients with tumors that are proven to be resistant to existing therapies Experimental therapy justified Adjuvant setting with standard clinical endpoints recognized by FDA High event rate Small sample size, short follow up Prognostic profiling data from cells that matters (chemo-resistant cells)
NSABP B-50I: KATHERINE Study Schema SURGERY Preoperative therapy: Trastuzumab/ Taxane ± Anthracycline Residual invasive tumor Herceptin T-DM1 Radiation per standard guidance; hormone therapy if ER or PgR pos
NSABP B-54-I: Penelope N=800 pts. with HR+/HER2- breast cancer No pcr and CPS-EG score 3 : Palbociclib 125 mg once daily p.o. d1-21, q29 for 12 cycles Neoadjuvant Chemotherapy Surgery +/- Radiotherapy R Placebo d1-21, q29 for 12 cycles Concomitant endocrine therapy according to local standards
Clinical and Pathologic Response to NC as a Guide of Further Loco-Regional Rx
Individualizing Loco-Regional Therapy with Neoadjuvant Chemotherapy Achievements Conversion of patients with inoperable tumors to operable candidates Conversion of mastectomy candidates to candidates for breast conserving surgery Improvement in cosmesis by reducing the size of lumpectomy in breast conserving surgery candidates with large tumors
Individualizing Loco-Regional Therapy with Neoadjuvant Chemotherapy Promises Reduction in the extent of axillary surgery by down-staging involved axillary nodes (SNB) Reduction in the extent of loco-regional XRT by down-staging primary tumors and axillary nodes Potential for eliminating some loco-regional therapy altogether (surgery or XRT) with use of more active regimens and/or appropriate patient selection (imaging/biomarkers)
Recently Activated U.S. Clinical Trials 55
Questions? 56