Phase 2 prospective open label study of neoadjuvant nab-paclitaxel, trastuzumab, and pertuzumab in patients with HER2-positive primary breast cancer

BACKGROUND

The objective of this study was to evaluate the safety and efficacy of nab-paclitaxel, trastuzumab, and pertuzumab as neoadjuvant therapy (NAT) in patients with human epidermal growth factor receptor 2 HER2+ breast cancer (HER2+ BC) to determine pathologic complete response (pCR), invasive disease-free survival (iDFS), and overall survival.

METHODS

Forty-five patients with HER2+ BC Stages II-III were to be enrolled from 2013 to 2017. Patients were treated with weekly nab-paclitaxel (100 mg/m² intravenously), weekly trastuzumab (4 mg/kg loading dose, then 2 mg/kg), and six cycles of pertuzumab (840 mg loading dose, then 420 mg intravenously day 1 every 21 days).

RESULTS

Median follow-up was 60 months (95% CI, 32.3-55.6) and pCR was 29/45 (64%). The 5-year iDFS for patients who achieved pCR (N = 29) was 96.3% (95% CI, 76.5-99.5) and non-pCR patients (N = 16) was 74.3% (95% CI, 39.1-91.0). The 5-year overall survival (N = 45) was 94.1% (95% CI, 77.6-98.5). Based on hormonal status, the 5-year iDFS for HR+ pCR patients (N = 14) was 92.3% (95% CI, 56.6-98.9) and for HR- (N = 15) was 100% (p = .3).

CONCLUSIONS

This anthracycline/carboplatin-free regimen with nab-paclitaxel achieved a pCR rate of 64% in patients with HER2+ BC. The 5-year iDFS in patients with and without pCR was 96.3% and 74.3%, respectively. The pCR rate is comparable with docetaxel, carboplatin, trastuzumab, and pertuzumab therapy in the NAT setting, but with fewer treatment-associated toxicities. This finding suggests the possibility of safe avoidance of anthracyclines and carboplatin as components of NAT in patients with HER2+ BC.

A randomized, double-blind, single-dose study (LAVENDER) to assess the safety, tolerability, pharmacokinetics, and immunogenicity of a combined infusion of ABP 980 and pertuzumab in healthy subjects

PURPOSE

ABP 980 (KANJINTI^™) is a biosimilar to reference product HERCEPTIN^® (trastuzumab RP). The goal of this study was to characterize the safety, tolerability, and immunogenicity of ABP 980 plus pertuzumab (PERJETA^®) when co-administered in a single infusion bag in healthy subjects.

METHODS

This randomized, double-blind, single-dose, 2-arm, parallel-group study (LAVENDER Study) evaluated an intravenous (IV) infusion of ABP 980 (6 mg/kg) plus pertuzumab (420 mg) combined in a single infusion bag relative to an IV infusion of trastuzumab RP (6 mg/kg) plus pertuzumab (420 mg) combined in a single infusion bag given over 60 min. The subjects were followed for 92 days post dosing.

RESULTS

A total of 42 subjects were enrolled in the study and treated with investigational product. Due to an operational issue during dosing, the first 6 subjects enrolled in the study were replaced. A total of 36 randomized subjects, n = 18 for ABP 980 plus pertuzumab and n = 18 for trastuzumab RP plus pertuzumab, were treated. Resulting serum concentrations of ABP 980 and trastuzumab RP were similar. There were no serious adverse events, no deaths, and no cardiac disorders during the study. No subject developed anti-drug antibodies throughout the study.

CONCLUSIONS

This study demonstrated the safety and tolerability of ABP 980 and pertuzumab admixture in a single infusion bag. The safety profiles and pharmacokinetic parameters of ABP 980 and pertuzumab were consistent with what is known for trastuzumab RP and pertuzumab.

CLINICAL TRIAL LISTING

EudraCT 2018-002903-33.

Cost-effectiveness of treatments for HER2-positive metastatic breast cancer and associated metastases: an overview of systematic reviews

Introduction: Treatment of human epithelial growth factor receptor 2 (HER2)-positive breast cancer has rapidly evolved over the past decades with the addition of trastuzumab, lapatinib, pertuzumab, and trastuzumab emtansine (T-DM1). These treatments have dramatically impacted the survival of HER2-positive metastatic breast cancer (mBC) patients. Nonetheless, these agents are associated with high price tags, begging the question, 'Are treatments for HER2-positive metastatic breast cancer and associated metastases cost-effective'?Areas covered: We examine evidence on the cost-effectiveness of treatments for HER2-positive metastatic breast cancer and associated metastases through a review of systematic reviews on the topic. Additionally, we discuss the implications of our findings and provide recommendations for future directions in the assessment of the cost-effectiveness of targeted directed agents for HER2-positive mBC.Expert opinion: Heterogeneous evidence from cost-effectiveness studies on the use of targeted directed agents for HER2-positive mBC across the world caution against cross-country comparisons of the value of such treatments. It also militates in favor of the production and use of cost-effectiveness analyses for local rather than global decision-making, thus ensuring that economic evaluations reflect the needs of local decision-makers and populations for which they are devised.

Evolution of overall survival and receipt of new therapies by subtype among 20 446 metastatic breast cancer patients in the 2008-2017 ESME cohort

Background

Treatment strategies for metastatic breast cancer (MBC) have made great strides over the past 10 years. Real-world data allow us to evaluate the actual benefit of new treatments. ESME (Epidemio-Strategy-Medico-Economical)-MBC, a nationwide observational cohort (NCT03275311), gathers data of all consecutive MBC patients who initiated their treatment in 18 French Cancer Centres since 2008.

Patients and methods

We evaluated overall survival (OS) in the whole cohort (N = 20 446) and among subtypes: hormone receptor positive, human epidermal growth factor 2 negative (HR+/HER2−; N = 13 590), HER2+ (N = 3919), and triple-negative breast cancer (TNBC; N = 2937). We performed multivariable analyses including year of MBC diagnosis as one of the covariates, to assess the potential OS improvement over time, and we described exposure to newly released drugs at any time during MBC history by year of diagnosis (YOD).

Results

The median follow-up of the whole cohort was 65.5 months (95% CI 64.6-66.7). Year of metastatic diagnosis appears as a strong independent prognostic factor for OS [Year 2016 HR 0.89 (95% CI 0.82-0.97); P = 0.009, using 2008 as reference]. This effect is driven by the HER2+ subcohort, where it is dramatic [Year 2016 HR 0.52 (95% CI 0.42-0.66); P < 0.001, using 2008 as reference]. YOD had, however, no sustained impact on OS among patients with TNBC [Year 2016 HR 0.93 (95% CI 0.77-1.11); P = 0.41, using 2008 as reference] nor among those with HR+/HER2– MBC [Year 2016 HR 1.02 (95% CI 0.91-1.13); P = 0.41, using 2008 as reference]. While exposure to newly released anti-HER2 therapies appeared very high (e.g. >70% of patients received pertuzumab from 2016 onwards), use of everolimus or eribulin was recorded in less than one-third of HR+/HER2– and TNBC cohorts, respectively, whatever YOD.

Conclusion

OS has dramatically improved among HER2+ MBC patients, probably in association with the release of several major HER2-directed therapies, whose penetrance was high. This trend was not observed in the other subtypes, but the impact of CDK4/6 inhibitors cannot yet be assessed.

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OS of HER2+ MBC patients keeps improving over time [Year 2016 HR 0.52 (95% CI 0.42-0.66); P < 0.001, using 2008 as reference].

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This effect seems timely related to the release of drugs demonstrated to improve survival in clinical trials.

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OS gains observed in real life among HER2+ MBC patients are at least equivalent to those observed in clinical trials.

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YOD had no sustained impact on OS among patients with TNBC and luminal MBC.

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The impact of CDK4/6 inhibitors cannot yet be assessed in this cohort.

Immunogenicity and antitumor efficacy of a novel human PD-1 B-cell vaccine (PD1-Vaxx) and combination immunotherapy with dual trastuzumab/pertuzumab-like HER-2 B-cell epitope vaccines (B-Vaxx) in a syngeneic mouse model

Therapeutic blockade of PD-1/PD-L1 signaling with monoclonal antibodies (mAbs) has shown clinical success and activity across a broad set of cancer subtypes. However, monotherapy with PD-1/PD-L1 inhibitors are only effective in a subset of patients and ongoing studies show efficacy of treatment depends on a combinatorial approach. Contrary to mAbs chimeric B-cell cancer vaccines incorporating a “promiscuous” T-cell epitope have the advantage of producing a polyclonal B-cell antibody that can potentially induce memory B- and T-cell responses, while reducing immune evasion and suppression. Here, we describe a novel PD-1 B-cell peptide epitope vaccine (amino acid 92–110; PD1-Vaxx) linked to a measles virus fusion peptide (MVF) amino acid 288–302 via a four amino acid residue (GPSL) emulsified in Montanide ISA 720VG that aims to induce the production of polyclonal antibodies that block PD-1 signaling and thus trigger anticancer effects similar to nivolumab. In preclinical studies, the PD1-Vaxx outperformed the standard anti-mouse PD-1 antibody (mAb 29F.1A12) in a mouse model of human HER-2 expressing colon carcinoma. Furthermore, the combination of PD1-Vaxx with combo HER-2 peptide vaccine (B-Vaxx) showed enhanced inhibition of tumor growth in colon carcinoma BALB/c model challenged with CT26/HER-2 cells. The PD-1 or combined vaccines were safe with no evidence of toxicity or autoimmunity.

Phase I Immunotherapy Trial with Two Chimeric HER-2 B-Cell Peptide Vaccines Emulsified in Montanide ISA 720VG and Nor-MDP Adjuvant in Patients with Advanced Solid Tumors

PURPOSE

This first-in-human phase I study (NCT01417546) evaluated the safety profile, optimal immunologic/biological dose (OID/OBD), and immunogenicity of the combination of two peptide B-cell epitope vaccines engineered to represent the trastuzumab- and pertuzumab-binding sites. Although trastuzumab and pertuzumab have been approved for clinical use, patients often develop resistance to these therapies. We have advanced a new paradigm in immunotherapy that focuses on humoral responses based on conformational B-cell epitope vaccines.

PATIENTS AND METHODS

The vaccine is comprised of two chimeric HER-2 B-cell peptide vaccines incorporating a "promiscuous T-cell epitope." Patients were immunized with the vaccine constructs emulsified with nor-muramyl-dipeptide adjuvant in a water-in-oil Montanide ISA 720VG vehicle. Eligible patients with metastatic and/or recurrent solid tumors received three inoculations every 3 weeks.

RESULTS

Forty-nine patients with a median of 4 prior lines of chemotherapy received at least 1 vaccination. Twenty-eight patients completed the 3 vaccination regimens. Six patients received 1 six-month boost after the regimen, and one patient received 7 six-month boosts. No serious adverse reactions or dose-limiting toxicities were observed. The vaccine was well tolerated with dose level 2 as the recommended phase II dose. The most common related toxicity in all patients was injection-site reactions (24%). Two patients had a partial response, 14 had stable disease, and 19 had progressive disease.

CONCLUSIONS

The study vaccine is safe, exhibits antitumor activity, and shows preliminary indication that peptide vaccination may avoid therapeutic resistance and offer a promising alternative to monoclonal antibody therapies.

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.

Targeting HER2 in Advanced Breast Cancer

Human epidermal growth factor receptor 2 (HER2) is a human oncogene that is amplified in approximately 20% of breast cancers, and portends a worse prognosis if not treated with anti-HER2 agents. The advent of targeted anti-HER2 therapies has dramatically improved disease control and survival in patients with metastatic HER2-positive breast cancer, and is now considered standard of care in the first-line setting and beyond. This review summarizes the currently available data on targeted anti-HER2 therapies from completed randomized phase III clinical trials, and briefly discusses emerging advances that will address unmet needs in metastatic HER2-positive breast cancer.

Cost-effectiveness analysis of 1st through 3rd line sequential targeted therapy in HER2-positive metastatic breast cancer in the United States

PURPOSE

Based on available phase III trial data, we performed a cost-effectiveness analysis of different treatment strategies that can be used in patients with newly diagnosed HER2-positive metastatic breast cancer (mBC).

PATIENTS AND METHODS

We constructed a Markov model to assess the cost-effectiveness of four different HER2 targeted treatment sequences in patients with HER2-positive mBC treated in the U.S. The model followed patients weekly over their remaining life expectancies. Health states considered were progression-free survival (PFS) 1st to 3rd lines, and death. Transitional probabilities were based on published phase III trials. Cost data (2015 US dollars) were captured from the U.S. Centers for Medicare and Medicaid Services (CMS) drug payment table and physician fee schedule. Health utility data were extracted from published studies. The outcomes considered were PFS, OS, costs, QALYs, the incremental cost per QALY gained ratio, and the net monetary benefit. Deterministic and probabilistic sensitivity analyses assessed the uncertainty around key model parameters and their joint impact on the base-case results.

RESULTS

The combination of trastuzumab, pertuzumab, and docetaxel (THP) as first-line therapy, trastuzumab emtansine (T-DM1) as second-line therapy, and lapatinib/capecitabine third-line resulted in 1.81 QALYs, at a cost of $335,231.35. The combination of trastuzumab/docetaxel as first line without subsequent T-DM1 or pertuzumab yielded 1.41 QALYs, at a cost of $175,240.69. The least clinically effective sequence (1.27 QALYs), but most cost-effective at a total cost of $149,250.19, was trastuzumab/docetaxel as first-line therapy, T-DM1 as second-line therapy, and trastuzumab/lapatinib as third-line therapy.

CONCLUSION

Our results suggest that THP as first-line therapy, followed by T-DM1 as second-line therapy, would require at least a 50 % reduction in the total drug acquisition cost for it to be considered a cost-effective strategy.

Resistance to Targeted Therapies in Breast Cancer

Seventy five percent of all breast cancer (BC) patients express estrogen receptor (ER) but a quarter to half of patients with ER positive BC relapse on ET (endocrine therapy), tamoxifen, aromatase inhibitors (AIs), surgical castration, amongst other treatment strategies. ER positive BC at relapse loses ER expression in 20 % of cases and reduces quantitative ER expression most of the time. ER is not the only survival pathway driving ER positive BC and escape pathways intrinsic or acquired are activated during ET. This overview gives an account of ligand-independent ER activation, namely by receptor networks cross talk, and by the various genomic factors and mechanisms leading to ET response failure. Also the mechanisms of Her1 and Her2 inhibition resistance are dealt within this overview, along with the therapeutic indications and limitations of tyrosine kinase inhibitors, PARP inhibitors, PI3K/AKT/mTOR inhibitors, RAS/RAF/MEK/ERK/MAPK inhibitors, and antiangiogenic drugs. In spite of the many advances in controlling the division of BC cells and the progression of BC tumors these still remain the main cause of death among women in age range of 20-50 years requiring even more efforts in new therapeutic approaches besides the drugs within the scope of the overview.

Better Together: Targeted Combination Therapies in Breast Cancer

Recent discoveries both in cell proliferation and survival mechanisms and new antineoplastic agents have led to deep change in the breast cancer treatment paradigm. Nonetheless, all of the progress in knowledge and strategy has not been enough to overcome mechanisms of escape and resistance put in place by the tumor cells. New targeted agents mean new possibilities for combinations, a viable option to try to stop compensatory pathways of tumor growth activated in response to therapeutics. The main challenges in designing a combined therapy come from the variety of subtypes of breast cancer (luminal A, luminal B, HER2-enriched, and basal-like) and from the multitude of pathways each subtype can exploit. Recent research has focused on dual blockade of HER2 (trastuzumab-lapatinib; trastuzumab-pertuzumab) and concomitant blockade of the endocrine driver and other pathways such as the PI3K/AKT/mTOR pathway (everolimus-exemestane), HER2 (trastuzumab/lapatinib-endocrine therapy) and the cell cycle through cyclin-dependent kinase inhibition (letrozole-palbociclib). This combined and personalized approach to treatment needs a profound knowledge of the mechanisms leading to proliferation in each tumor subtype. Deepening our understanding of tumor growth is mandatory to keep improving the efficacy of combination therapy.

Impact of prior anthracycline or taxane use on eribulin effectiveness as first-line treatment for metastatic breast cancer: results from two phase 2, multicenter, single-arm studies

Eribulin mesylate has efficacy in patients who have received ≥2 prior chemotherapies for metastatic breast cancer (MBC) including an anthracycline and taxane. Phase 2 trials showed clinical activity and acceptable tolerability of first-line eribulin (HER2− MBC; Study 206) and eribulin plus trastuzumab (HER2+ MBC; Study 208). Prespecified analyses evaluated efficacy by prior anthracycline and/or taxane use. Patients received eribulin mesylate (1.4 mg/m² IV; Days 1 and 8) and, in Study 208, trastuzumab (8 mg/kg IV/Cycle 1, then 6 mg/kg; Day 1) in 21-day cycles. Endpoints included objective response rate (ORR), progression-free survival (PFS), and tolerability. In Study 206 (N = 56), 48 % of patients had received prior anthracycline, 46 % prior taxane, 36 % prior anthracycline and taxane, and 41 % were chemotherapy-naïve. In Study 208 (N = 52), these percentages were 21, 44, 17, and 52 %, respectively. In Study 206, ORR and median PFS were similar for anthracycline-pretreated (25.9 %, 5.8 months), taxane-pretreated (26.9 %, 5.8 months), anthracycline- and taxane-pretreated (25.0 %, 6.7 months), and anthracycline/taxane-naïve patients (30.4 %, 7.6 months). In Study 208, ORR/median PFS were 63.6 %/6.7 months among anthracycline-pretreated patients, 56.5 %/6.8 months among taxane-pretreated patients, 55.6 %/5.9 months among anthracycline- and taxane-pretreated patients, and 81.5 %/13.1 months among anthracycline/taxane-naïve patients. Tolerability was generally similar among subgroups. In these studies, first-line eribulin in HER2− MBC and eribulin/trastuzumab in HER2+ MBC was effective with acceptable tolerability, regardless of prior anthracycline/taxane treatment. Prior chemotherapy was associated with lower ORR and shorter PFS with eribulin/trastuzumab in HER2+ MBC but not with eribulin in HER2− MBC.

"Vertical" Inhibition of HER2 Yields Horizontal Gains in the Clinic

HER2-targeted therapy has moved beyond trastuzumab to include other monoclonals targeting the cell surface, receptor tyrosine kinase inhibitors of HER2, and antibody-drug conjugates. Afatinib, a small molecule receptor tyrosine kinase inhibitor, now joins the ranks of HER2-targeting agents in combination with trastuzumab. The combination brings new opportunities and challenges.