Trastuzumab Emtansine for Residual Invasive HER2-Positive Breast Cancer

BACKGROUND

Patients who have residual invasive breast cancer after receiving neoadjuvant chemotherapy plus human epidermal growth factor receptor 2 (HER2)-targeted therapy have a worse prognosis than those who have no residual cancer. Trastuzumab emtansine (T-DM1), an antibody-drug conjugate of trastuzumab and the cytotoxic agent emtansine (DM1), a maytansine derivative and microtubule inhibitor, provides benefit in patients with metastatic breast cancer that was previously treated with chemotherapy plus HER2-targeted therapy.

METHODS

We conducted a phase 3, open-label trial involving patients with HER2-positive early breast cancer who were found to have residual invasive disease in the breast or axilla at surgery after receiving neoadjuvant therapy containing a taxane (with or without anthracycline) and trastuzumab. Patients were randomly assigned to receive adjuvant T-DM1 or trastuzumab for 14 cycles. The primary end point was invasive disease-free survival (defined as freedom from ipsilateral invasive breast tumor recurrence, ipsilateral locoregional invasive breast cancer recurrence, contralateral invasive breast cancer, distant recurrence, or death from any cause).

RESULTS

At the interim analysis, among 1486 randomly assigned patients (743 in the T-DM1 group and 743 in the trastuzumab group), invasive disease or death had occurred in 91 patients in the T-DM1 group (12.2%) and 165 patients in the trastuzumab group (22.2%). The estimated percentage of patients who were free of invasive disease at 3 years was 88.3% in the T-DM1 group and 77.0% in the trastuzumab group. Invasive disease-free survival was significantly higher in the T-DM1 group than in the trastuzumab group (hazard ratio for invasive disease or death, 0.50; 95% confidence interval, 0.39 to 0.64; P<0.001). Distant recurrence as the first invasive-disease event occurred in 10.5% of patients in the T-DM1 group and 15.9% of those in the trastuzumab group. The safety data were consistent with the known safety profile of T-DM1, with more adverse events associated with T-DM1 than with trastuzumab alone.

CONCLUSIONS

Among patients with HER2-positive early breast cancer who had residual invasive disease after completion of neoadjuvant therapy, the risk of recurrence of invasive breast cancer or death was 50% lower with adjuvant T-DM1 than with trastuzumab alone. (Funded by F. Hoffmann-La Roche/Genentech; KATHERINE ClinicalTrials.gov number, NCT01772472 .).

Pertuzumab, trastuzumab, and standard anthracycline- and taxane-based chemotherapy for the neoadjuvant treatment of patients with HER2-positive localized breast cancer (BERENICE): a phase II, open-label, multicenter, multinational cardiac safety study

Background

Anti-HER2 therapies are associated with a risk of increased cardiac toxicity, particularly when part of anthracycline-containing regimens. We report cardiac safety of pertuzumab, trastuzumab, and chemotherapy in the neoadjuvant treatment of HER2-positive early breast cancer.

Patients and methods

BERENICE (NCT02132949) is a nonrandomized, phase II, open-label, multicenter, multinational study in patients with normal cardiac function. In the neoadjuvant period, cohort A patients received four cycles of dose-dense doxorubicin and cyclophosphamide, then 12 doses of standard paclitaxel plus four standard trastuzumab and pertuzumab cycles. Cohort B patients received four standard fluorouracil/epirubicin/cyclophosphamide cycles, then four docetaxel cycles with four standard trastuzumab and pertuzumab cycles. The primary end point was cardiac safety during neoadjuvant treatment, assessed by the incidence of New York Heart Association class III/IV heart failure and of left ventricular ejection fraction declines (≥10 percentage-points from baseline and to a value of <50%). The main efficacy end point was pathologic complete response (pCR, ypT0/is ypN0). Results are descriptive.

Results

Safety populations were 199 and 198 patients in cohorts A and B, respectively. Three patients [1.5%; 95% confidence interval (CI) 0.31% to 4.34%] in cohort A experienced four New York Heart Association class III/IV heart failure events. Thirteen patients (6.5%; 95% CI 3.5% to 10.9%) in cohort A and four (2.0%; 95% CI 0.6% to 5.1%) in cohort B experienced at least one left ventricular ejection fraction decline. No new safety signals were identified. pCR rates were 61.8% and 60.7% in cohorts A and B, respectively. The highest pCR rates were in the HER2-enriched PAM50 subtype (75.0% and 73.7%, respectively).

Conclusion

Treatment with pertuzumab, trastuzumab, and common anthracycline-containing regimens for the neoadjuvant treatment of early breast cancer resulted in cardiac and general safety profiles, and pCR rates, consistent with prior studies with pertuzumab.

Clinical Trial Information

NCT02132949.

Abstract P5-20-04: Safety of adjuvant treatment with pertuzumab plus trastuzumab after neoadjuvant anthracycline-based chemotherapy in patients with HER2-positive localized breast cancer: Updated results from the BERENICE study

Background Anti-HER2 therapies are associated with a risk of cardiac toxicity, particularly as part of anthracycline-based regimens. BERENICE (NCT02132949), a nonrandomized, Phase 2 cardiac safety study showed neoadjuvant treatment with pertuzumab (P) + trastuzumab (H) and 2 common anthracycline–taxane-based regimens had a safety profile consistent with prior studies of P+H, and was associated with high pathologic complete response rates. Here we report safety data from the P+H adjuvant treatment period (AP).

Methods Patients (pts) with centrally confirmed, localized HER2-positive breast cancer and normal cardiac function received 4 q2w dose-dense doxorubicin and cyclophosphamide cycles (60/600mg/m2) then 12 qw paclitaxel injections (80mg/m2; Cohort A), or 4 q3w fluorouracil/epirubicin/cyclophosphamide cycles (500/100/600 mg/m2) then 4 q3w docetaxel cycles (75mg/m2, up to 100mg/m2;Cohort B). In both cohorts, 4 q3w cycles of P (loading:840mg; maintenance:420mg) + H (loading:8mg/kg; maintenance:6mg/kg) were started with taxane therapy and continued in the adjuvant setting (for up to 13 cycles to complete 1 year of treatment). Surgery was scheduled after 8 cycles of preoperative therapy. Primary endpoints were incidence of New York Heart Association (NYHA) Class III/IV heart failure and incidence of left ventricular ejection fraction (LVEF) declines (≥10%-points from baseline to &lt;50%; asymptomatic and symptomatic events) assessed by ECHO/MUGA. Confirmed LVEF declines were defined as significant LVEF declines at 2 consecutive visits.

Results In total, 397 pts received ≥1 dose of study medication and were included in the overall treatment period (OTP) safety analysis. Of these, 371 (Cohort A:181; Cohort B:190) pts entered the AP and were included in the AP safety analysis. Mean (SD) number of AP treatment cycles of P and H were 12.3 (2.0) in Cohort A and 12.3 (2.2) in Cohort B. In the AP, incidence of heart failure was minimal (0.5%) and confirmed LVEF decline incidence was low (Table 1).

Table 1: Cardiac AE Cohort ACohort B OTP n=199AP n=181OTP n=198OTP n=190NYHA Class III/IV heart failure    Events, n4011Pts with event, n (%)3(1.5)01(0.5)1(0.5)LVEF decline    Events, n36223429Pts with LVEF decline, n (%)21(10.6)14(7.7)22(11.1)20(10.5)Pts with confirmed LVEF decline, n (%)7(3.5)5(2.8)7(3.5)6(3.2)

General adverse events (AEs) are shown in Table 2; 26 (14.4%) pts in Cohort A and 45 (23.7%) in Cohort B had diarrhea AEs (mostly grade 1).

Table 2: General AE Cohort ACohort BPts, n (%)OTP n=199AP n=181OTP n=198AP n=190Any AE198(99.5)171(94.5)198(100.0)171(90.0)Grade ≥3 AE109(54.8)23(12.7)126(63.6)40(21.1)Serious AE54(27.1)15(8.3)61(30.8)17(8.9)AE leading to P or H discontinuation19(9.5)9(5.0)14(7.1)11(5.8)

Conclusion P+H in the adjuvant setting, following P+H with anthracycline-based regimens in the neoadjuvant setting, are associated with low incidence of cardiac AEs. Cardiac safety results for P+H in the AP and OTP of BERENICE were consistent with results from prior studies evaluating adjuvant treatment with single-agent H, suggesting the addition of P to H in the adjuvant setting does not increase cardiac toxicity.

Citation Format: Dang C, Ewer MS, Delaloge S, Ferrero J-M, Verrill M, Colomer R, Vieira C, de la Cruz Merino L, Lucas J, Werner TL, Douthwaite H, Bradley D, Waldron-Lynch M, Eng-Wong J, Swain SM. Safety of adjuvant treatment with pertuzumab plus trastuzumab after neoadjuvant anthracycline-based chemotherapy in patients with HER2-positive localized breast cancer: Updated results from the BERENICE study [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-20-04.

Efficacy of trastuzumab emtansine (T-DM1) in patients (pts) with HER2+ metastatic breast cancer (MBC) previously treated with pertuzumab (P)

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Background: T-DM1 was approved for pts with HER2+ MBC previously treated with trastuzumab (H) and a taxane based on the phase III EMILIA study. P in combination with H + docetaxel (T) later became the first-line standard of care for HER2+ MBC, but there are limited data on T-DM1 efficacy in pts who previously received P. We present exploratory efficacy results from pts treated with T-DM1 any time after P from 2 phase III studies: CLEOPATRA and PHEREXA. Methods: CLEOPATRA (NCT00567190) and PHEREXA (NCT01026142) are randomized, 2-arm trials evaluating P-based regimens for HER2+ MBC. CLEOPATRA studies H + T + P vs HT + placebo in pts with no prior anti-HER2 treatment (tx) or chemotherapy for MBC, while PHEREXA studies H + capecitabine (C) +/− P in pts who progressed during/after previous H tx for MBC. We assessed overall survival (OS) in an exploratory analysis of pts who either received or did not receive T-DM1 at any time after discontinuing study-assigned tx in CLEOPATRA or PHEREXA. Results: Of 408 pts who received HTP in CLEOPATRA and 228 pts who received HCP in PHEREXA, 32 and 43 pts received subsequent T-DM1, respectively (Table). Median duration of T-DM1 tx was 7.1 mo (range 0−44) and 4.2 mo (range 0−22), respectively, and median time from discontinuation of P to start of T-DM1 was 3.5 mo (range 1−47) and 10.6 mo (range 1−28). Conclusions: Although data are limited in these exploratory analyses, our results provide additional evidence of T-DM1 clinical activity in pts with HER2+ MBC who progressed on prior P + H, a finding with real-world implications. Clinical trial information: NCT00567190, NCT01026142. [Table: see text]

Randomized Phase III Trial of Trastuzumab Plus Capecitabine With or Without Pertuzumab in Patients With Human Epidermal Growth Factor Receptor 2-Positive Metastatic Breast Cancer Who Experienced Disease Progression During or After Trastuzumab-Based Therapy

Purpose To assess the efficacy and safety of trastuzumab plus capecitabine with or without pertuzumab in patients with human epidermal growth factor receptor 2-positive metastatic breast cancer who experienced disease progression during or after trastuzumab-based therapy and received a prior taxane. Patients and Methods Patients were randomly assigned to arm A: trastuzumab 8 mg/kg → 6 mg/kg once every 3 weeks plus capecitabine 1,250 mg/m² twice a day (2 weeks on, 1 week off, every 3 weeks); or arm B: pertuzumab 840 mg → 420 mg once every 3 weeks plus trastuzumab at the same dose and schedule as arm A plus capecitabine 1,000 mg/m² on the same schedule as arm A. The primary end point was independent review facility-assessed progression-free survival (IRF PFS). Secondary end points included overall survival (OS) and safety. Hierarchical testing procedures were used to control type I error for statistical testing of IRF PFS, OS, and objective response rate. Results Randomly assigned (intent-to-treat) populations were 224 and 228 patients in arms A and B, respectively. Median IRF PFS at 28.6 and 25.3 months' median follow-up was 9.0 v 11.1 months (hazard ratio, 0.82; 95% CI, 0.65 to 1.02; P = .0731) and interim OS was 28.1 v 36.1 months (hazard ratio, 0.68; 95% CI, 0.51 to 0.90). The most common adverse events (all grades; incidence of ≥ 10% in either arm and ≥ 5% difference between arms) were hand-foot syndrome, nausea, and neutropenia in arm A, and diarrhea, rash, and nasopharyngitis in arm B. Conclusion The addition of pertuzumab to trastuzumab and capecitabine did not significantly improve IRF PFS. An 8-month increase in median OS to 36.1 months with pertuzumab was observed. Statistical significance for OS cannot be claimed because of the hierarchical testing of OS after the primary PFS end point; however, the magnitude of OS difference is in keeping with prior experience of pertuzumab in metastatic breast cancer. No new safety signals were identified.

Abstract OT3-1-01: A two-cohort, phase II, cardiac safety study of pertuzumab, trastuzumab, and neoadjuvant anthracycline-based chemotherapy in patients with HER2-positive, locally advanced, inflammatory, or early breast cancer

Background: In HER2-positive early breast cancer (BC), neoadjuvant pertuzumab (P) + trastuzumab (T) + docetaxel (D) significantly increased pathologic complete response (pCR) rates compared with T+D (Gianni L, et al. Lancet Oncol 2012); high pCR rates were also seen with P+T in combination with anthracycline- and non-anthracycline-based regimens (Schneeweiss A, et al. Ann Oncol 2013). Neoadjuvant P+T + chemotherapy was well tolerated, with little increased toxicity associated with the addition of P. Although there was a higher rate of cardiac adverse events (AEs), left ventricular systolic dysfunction (LVSD), and left ventricular ejection fraction (LVEF) declines in P+T-containing arms compared with arms without P, these events were generally asymptomatic, reversible, and patients (pts) recovered with no sequelae. No data are available for neoadjuvant P-based regimens that include paclitaxel (Ptx) and dose-dense doxorubicin plus cyclophosphamide (ddAC), despite these being widely used in (neo)adjuvant BC therapy. This study will evaluate the cardiac safety of two anthracycline-based neoadjuvant regimens in combination with P+T. Following surgery, all pts will receive adjuvant P+T.

Trial design: In this non-randomized, open-label, phase II study, two parallel cohorts of pts receive different P-based neoadjuvant treatment regimens. In Cohort A, pts receive four 2-weekly cycles of ddAC, followed by 12 doses of weekly Ptx, plus four 3-weekly (q3w) cycles of P+T from the start of Ptx. In Cohort B, pts receive four q3w cycles of 5-fluorouracil, epirubicin, and cyclophosphamide, followed by four q3w cycles of D, plus four q3w cycles of P+T from the start of D. Following surgery, both cohorts receive 13 cycles of P+T.

Eligibility: Pts with HER2-positive, locally advanced, inflammatory, or early BC (size &gt;2 cm or &gt;5 mm and node-positive) are eligible if they have a baseline LVEF ≥55% and an ECOG performance status ≤1. Among the exclusion criteria are prior incisional biopsy or excision of the primary tumor, prior systemic or radiation therapy for cancer, and prior chemopreventive agents. Pts are also excluded if they have poorly controlled hypertension, angina requiring medication, a history of congestive heart failure, serious or uncontrolled cardiac arrhythmia requiring treatment, or myocardial infarction within 6 months prior to enrollment.

Aims: The primary objective is cardiac safety during the neoadjuvant period, assessed by incidence of symptomatic LVSD and LVEF changes. Secondary objectives include cardiac safety in the adjuvant and post-treatment periods, incidence of all AEs, pCR rate, event-free survival, invasive disease-free survival, and overall survival.

Statistical methods: No statistical hypothesis testing will be performed. Safety and efficacy results will be summarized descriptively. A sample size of 200 pts per cohort is expected to provide sufficient data to evaluate the cardiac safety of each regimen with acceptable precision (exact Clopper-Pearson 95% CIs) around the expected rates.

Accrual: The first patient in is planned for August 2014.

Citation Format: Sandra M Swain, Michael S Ewer, Hannah Douthwaite, Tania Szado, Maeve Waldron-Lynch, Chau Dang. A two-cohort, phase II, cardiac safety study of pertuzumab, trastuzumab, and neoadjuvant anthracycline-based chemotherapy in patients with HER2-positive, locally advanced, inflammatory, or early breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr OT3-1-01.