Biomarker results from the AVADO phase 3 trial of first-line bevacizumab plus docetaxel for HER2-negative metastatic breast cancer

Background:

Combining bevacizumab with first-line chemotherapy significantly improves progression-free survival (PFS) in HER2-negative metastatic breast cancer (mBC). However, identification of patients benefitting most from bevacizumab remains elusive. The AVADO trial included an extensive optional exploratory biomarker programme.

Methods:

Patients with HER2-negative mBC were randomised to receive docetaxel with placebo or bevacizumab. The primary end point was PFS. Plasma samples were analysed using a multiplex ELISA. Blood mRNA expression was assessed using quantitative PCR. Tumour tissue samples were analysed by immunohistochemistry. Single-nucleotide polymorphisms (SNPs) involved in the VEGF pathway were analysed in germline DNA.

Results:

Samples for biomarker analysis were available from 24–54% of the 736 treated patients (depending on specimen type). The most consistent potential predictive effect was observed with plasma VEGF-A and VEGFR-2; high baseline concentrations were associated with greater treatment effect. Blood mRNA analyses suggested a greater bevacizumab effect in patients with high VEGF₁₂₁. No consistent predictive effect was seen for tumour neuropilin or other candidate tumour markers by immunohistochemistry, or for any of the SNPs investigated.

Conclusion:

Plasma VEGF-A and VEGFR-2 are potential predictive markers for bevacizumab efficacy, supporting findings in gastric and pancreatic cancers. Plasma VEGF-A is being evaluated prospectively in mBC in the MERiDiAN trial.     

Paclitaxel and bevacizumab with or without capecitabine as first-line treatment for HER2-negative locally recurrent or metastatic breast cancer: A multicentre,open-label,randomised phase 2 trial

BackgroundThe addition of bevacizumab to paclitaxel or capecitabine has demonstrated improved progression-free survival (PFS) and objective response rate (ORR) as compared with chemotherapy alone in patients with HER2-negative locally recurrent or metastatic breast cancer (LR/MBC). We evaluated the efficacy and safety of first-line therapy of paclitaxel and bevacizumab with or without capecitabine in patients with HER2-negative LR/MBC.MethodsIn this multicentre, open-label, randomised phase II trial, women with HER2-negative LR/MBC were randomly assigned in a 1:1 ratio to paclitaxel (90 mg/m² intravenously [IV] on days 1, 8, and 15) and bevacizumab (10 mg/kg IV on days 1 and 15) every 4 weeks for six cycles, followed by bevacizumab (15 mg/kg IV on day 1) every 3 weeks (AT) or to paclitaxel (90 mg/m² IV on days 1 and 8), bevacizumab (15 mg/kg IV on day 1) and capecitabine (825 mg/m² orally twice daily on days 1–14) every 3 weeks for eight cycles, followed by bevacizumab and capecitabine at the same doses every 3 weeks (ATX). The primary end-point was investigator-assessed PFS. Secondary end-points included ORR, duration of response, overall survival (OS) and safety. Exploratory analyses were conducted to evaluate the impact of capecitabine on OS and to validate a novel prognostic model. This trial is registered with EudraCT, number 2006-006058-83.FindingsMedian PFS was significantly longer in ATX as compared with AT (11.2 months versus 8.4 months; stratified hazard ratio (HR), 0.52; 95% confidence interval (CI), 0.41–0.67; p < 0.0001). The ORR in ATX patients with measurable disease (n = 268) was higher than that in AT (69% versus 51%; p = 0.01). The median duration of response was 6.8 versus 5.4 months for, respectively, ATX and AT (p < 0.0001). Median OS was 24.2 months for ATX and 23.1 months for AT (p = 0.53). The increased rate of grade 3–4 adverse events related to the addition of capecitabine, being hand-foot syndrome (34% versus 0% for AT) and neutropenia (20% versus 12% for AT), generally did not preclude continuation of treatment. Exploratory analyses indicated that 1) patients receiving capecitabine at some line for treatment have significantly improved OS and 2) a prognostic model can classify patients into three risk groups associated with OS.InterpretationIn patients with HER2-negative LR/MBC, addition of capecitabine to paclitaxel and bevacizumab significantly improved PFS, ORR and response duration. This combination was reasonably well tolerated and may be considered of use as first-line treatment in rapidly progressive disease.FundingF. Hoffmann-La Roche Ltd, the Netherlands.     

Safety results from a phase III study (TURANDOT trial by CECOG) of first-line bevacizumab in combination with capecitabine or paclitaxel for HER-2-negative locally recurrent or metastatic breast cancer

BackgroundWe report safety data from a randomised, phase III study (CECOG/BC.1.3.005) evaluating first-line bevacizumab plus paclitaxel or capecitabine for locally recurrent or metastatic breast cancer.Patients and methodsPatients aged ⩾18 years with human epidermal growth factor receptor-2-negative breast adenocarcinoma were randomised to Arm A: bevacizumab 10 mg/kg days 1 and 15; paclitaxel 90 mg/m² days 1, 8, and 15, every 4 weeks; or Arm B: bevacizumab 15 mg/kg day 1; capecitabine 1000 mg/m² b.i.d., days 1–14, every 3 weeks, until disease progression, unacceptable toxicity or consent withdrawal.ResultsA post hoc interim safety analysis included 561 patients (Arm A: 284, Arm B: 277). The regimens demonstrated similar frequencies of all-grade and serious adverse events (SAEs), but different safety profiles. Treatment-related events occurred in 85.2% (Arm A) and 78.0% (Arm B) of patients. Fatigue was most common in Arm A (30.6% versus 23.5% Arm B), and hand–foot syndrome (HFS) most common in Arm B (49.5% versus 2.5% Arm A). Diarrhoea (Arm A: 0.4%, Arm B: 1.4%) and pulmonary embolism (Arm A: 0.7%, Arm B: 1.1%) were the most frequently reported SAEs.ConclusionThese findings are in-line with safety data for bevacizumab plus paclitaxel or capecitabine, reported in previous phase III trials.     

Body mass index in HER2-negative metastatic breast cancer treated with first-line paclitaxel and bevacizumab

The evidence emerged from the TOURANDOT trial encourages evaluating the role of anthropometric determinants on treatment outcomes in HER2-negative metastatic breast cancer patients treated with bevacizumab-including regimens. We thus analyzed data from a subgroup of these patients from a larger cohort previously assessed for treatment outcomes. Patients were included in the present analysis if body mass index values had been recorded at baseline. Clinical benefit rates, progression free survival and overall survival were assessed for the overall study population and subgroups defined upon molecular subtype. One hundred ninety six patients were included (N:196). Body mass index showed no impact on clinical benefit rates in the overall study sample and in the luminal cancer subset (p = 0.12 and p = 0.79, respectively), but did so in the triple negative subgroup, with higher rates in patients with body mass index ≥25 (p = 0.03). In the overall study sample, body mass index did no impact progression free or overall survival (p = 0.33 and p = 0.67, respectively). Conversely, in triple negative patients, progression free survival was significantly longer with body mass index ≥25 (6 vs 14 months, p = 0.04). In this subset, overall survival was more favorable (25 vs 19 months, p = 0.02). The impact of the molecular subtype was confirmed in multivariate models including the length of progression free survival, and number of metastatic sites (p < 0.0001). Further studies are warranted to confirm our findings in more adequately sized, ad hoc, prospective studies.     

Final results of the double-blind placebo-controlled randomized phase 2 LOTUS trial of first-line ipatasertib plus paclitaxel for inoperable locally advanced/metastatic triple-negative breast cancer

Purpose

In LOTUS (NCT02162719), adding the oral AKT inhibitor ipatasertib to first-line paclitaxel for locally advanced/metastatic triple-negative breast cancer (aTNBC) improved progression-free survival (PFS; primary endpoint), with an enhanced effect in patients with PIK3CA/AKT1/PTEN-altered tumors (FoundationOne next-generation sequencing [NGS] assay). We report final overall survival (OS) results.

Methods

Eligible patients had measurable previously untreated aTNBC. Patients were stratified by prior (neo)adjuvant therapy, chemotherapy-free interval, and tumor immunohistochemistry PTEN status, and were randomized 1:1 to paclitaxel 80 mg/m² (days 1, 8, 15) plus ipatasertib 400 mg or placebo (days 1–21) every 28 days until disease progression or unacceptable toxicity. OS (intent-to-treat [ITT], immunohistochemistry PTEN-low, and PI3K/AKT pathway-activated [NGS PIK3CA/AKT1/PTEN-altered] populations) was a secondary endpoint.

Results

Median follow-up was 19.0 versus 16.0 months in the ipatasertib–paclitaxel versus placebo–paclitaxel arms, respectively. In the ITT population (n?=?124), median OS was numerically longer with ipatasertib–paclitaxel than placebo–paclitaxel (hazard ratio 0.80, 95% CI 0.50–1.28; median 25.8 vs 16.9 months, respectively; 1-year OS 83% vs 68%). Likewise, median OS favored ipatasertib–paclitaxel in the PTEN-low (n?=?48; 23.1 vs 15.8 months; hazard ratio 0.83) and PIK3CA/AKT1/PTEN-altered (n?=?42; 25.8 vs 22.1 months; hazard ratio 1.13) subgroups. The ipatasertib–paclitaxel safety profile was unchanged.

Conclusions

Final OS results show a numerical trend favoring ipatasertib–paclitaxel and median OS exceeding 2 years with ipatasertib–paclitaxel. Overall, results are consistent with the reported PFS benefit; interpretation within biomarker-defined subgroups is complicated by small sample sizes and TNBC heterogeneity.

     

Bevacizumab plus paclitaxel versus placebo plus paclitaxel as first-line therapy for HER2-negative metastatic breast cancer (MERiDiAN): A double-blind placebo-controlled randomised phase III trial with prospective biomarker evaluation

AimMERiDiAN evaluated plasma vascular endothelial growth factor-A (pVEGF-A) prospectively as a predictive biomarker for bevacizumab efficacy in metastatic breast cancer (mBC).MethodsIn this double-blind placebo-controlled randomised phase III trial, eligible patients had HER2-negative mBC previously untreated with chemotherapy. pVEGF-A was measured before randomisation to paclitaxel 90 mg/m² on days 1, 8 and 15 with either placebo or bevacizumab 10 mg/kg on days 1 and 15, repeated every 4 weeks until disease progression, unacceptable toxicity or consent withdrawal. Stratification factors were baseline pVEGF-A, prior adjuvant chemotherapy, hormone receptor status and geographic region. Co-primary end-points were investigator-assessed progression-free survival (PFS) in the intent-to-treat and pVEGF-A_high populations.ResultsOf 481 patients randomised (242 placebo–paclitaxel; 239 bevacizumab–paclitaxel), 471 received study treatment. The stratified PFS hazard ratio was 0.68 (99% confidence interval, 0.51–0.91; log-rank p = 0.0007) in the intent-to-treat population (median 8.8 months with placebo–paclitaxel versus 11.0 months with bevacizumab–paclitaxel) and 0.64 (96% confidence interval, 0.47–0.88; log-rank p = 0.0038) in the pVEGF-A_high subgroup. The PFS treatment-by-VEGF-A interaction p value (secondary end-point) was 0.4619. Bevacizumab was associated with increased incidences of bleeding (all grades: 45% versus 27% with placebo), neutropenia (all grades: 39% versus 29%; grade ≥3: 25% versus 13%) and hypertension (all grades: 31% versus 13%; grade ≥3: 11% versus 4%).ConclusionThe significant PFS improvement with bevacizumab is consistent with previous placebo-controlled first-line trials in mBC. Results do not support using baseline pVEGF-A to identify patients benefitting most from bevacizumab.Clinical trials registrationClinicalTrials.gov NCT01663727.     

State of the art therapy for HER2-negative metastatic breast cancer

Metastatic breast cancer (MBC) remains a challenging disease to treat with only a small minority of patients achieving long-term survival. Although great strides have been made in the fight against breast cancer, international consensus to the approach to treat the disease is lacking. Over the past few decades, the introduction of several new agents, including biologically-targeted agents, have impacted disease control as well as survival, albeit modestly. Despite these advances, treatment for the majority of breast cancer remains empirically based, especially in the approach to HER2-negative, endocrine non-sensitive disease. Taxane- and anthracycline-containing regimens continue to be a mainstay of MBC therapy; however, increasing use of these agents in the adjuvant and neoadjuvant settings provides a challenge for the treating oncologist. As such, this review will focus on state of the art therapy for patients with endocrine non-sensitive, HER2-negative MBC, highlighting recent advances offering new treatment paradigms.     

Phase 2 study of eribulin mesylate as first-line therapy for locally recurrent or metastatic human epidermal growth factor receptor 2-negative breast cancer

Eribulin mesylate, a novel non-taxane microtubule dynamics inhibitor, is approved for treatment of metastatic breast cancer (MBC) in patients who have previously received at least 2 chemotherapeutic regimens for MBC that should have included an anthracycline and a taxane in the adjuvant or metastatic setting. This phase 2 study evaluated efficacy and safety of eribulin as first-line therapy for human epidermal growth factor receptor 2-negative (HER2-negative) MBC. Patients with measurable HER2-negative locally recurrent breast cancer or MBC with ≥12 months since prior neoadjuvant or adjuvant (neo/adjuvant) chemotherapy received eribulin mesylate 1.4 mg/m² IV on days 1 and 8 of each 3-week cycle. Endpoints included objective response rate (ORR) per RECIST v1.1 (primary), safety, progression-free survival (PFS), clinical benefit rate (ORR + stable disease ≥6 months; CBR), and duration of response (DOR). Fifty-six patients were enrolled and received eribulin; 38 (68 %) had prior neo/adjuvant therapy, including 33 who had anthracycline and/or taxane-containing chemotherapy; 41 (73 %) had estrogen receptor-positive disease, and 12 (21 %) had estrogen receptor-negative, progesterone receptor-negative, and HER2-negative (triple-negative) disease. Patients received a median of 7 cycles (range 1–43); 6 (11 %) received treatment for ≥12 months. ORR was 29 % (95 % CI 17.3–42.2), CBR was 52 %, and median DOR was 5.8 months. Median PFS was 6.8 months. Thirty-six patients (64 %) had grade 3/4 treatment-related adverse events; most common were neutropenia (50 %), leukopenia (21 %), and peripheral neuropathy (21 %). These results demonstrate that eribulin has substantial antitumor activity as first-line treatment for HER2-negative MBC with acceptable safety.     

A phase III trial of exemestane plus bevacizumab maintenance therapy in patients with metastatic breast cancer after first-line taxane and bevacizumab: a GINECO group study

BackgroundMaintenance strategies beyond response or tumor stabilization with first-line chemotherapy in metastatic breast cancer (MBC) have not been extensively studied. Endocrine therapy combined with continued bevacizumab may be a helpful option for estrogen receptor (ER)-positive MBC.Patients and methodsIn this prospective, open-label, phase III study, patients with histologically confirmed ER-positive, HER2-negative MBC and non-progressive disease after 16–24 weeks of taxane plus bevacizumab (T + BEV) were randomized to continuation of T + BEV or maintenance bevacizumab plus exemestane (E + BEV). The primary end point was progression-free survival (PFS) from randomization. To have 80% power to detect an improvement in the 6-month PFS rate (PFS6m) from 50% to 65%, 186 assessable patients were needed for a total of 141 PFS events. An interim analysis was planned after 40% of the required events.ResultsThe interim analysis with 98 patients showed that the probability of reaching a statistically significant improvement in PFS by the end of the study was only 7%. This led the Independent Data and Monitoring Committee to recommend termination of patient enrollment. After a median of 21-month follow-up of all randomized patients (117 in total), PFS6m from randomization was 67.2% [95% confidence interval (CI) 53.6–77.7] with T + BEV and 55.2% (95% CI 41.5–66.9) with E + BEV [hazard ratio (HR): 1.0, 95% CI 0.7–1.5, P = 0.998]. Median PFS from BEV initiation was 12.5 and 12.3 months in the T + BEV and E + BEV arms, respectively. In the T + BEV arm, taxane was prematurely stopped for the majority of patients (94.9%), mainly due to toxicity (49.2%). Updated data after 35 months' median follow-up showed death rates of 44% and 55% in T + BEV and E + BEV arms, respectively.ConclusionIn this trial, maintenance therapy with E + BEV in ER-positive, HER2-negative MBC patients with no evidence of progression after first-line T + BEV did not achieve longer PFS compared with continuation of T + BEV.ClinicalTrials.govNCT01303679     

Paclitaxel plus bevacizumab or paclitaxel as first-line treatment for HER2-negative metastatic breast cancer in a multicenter national observational study

BackgroundBevacizumab combined with paclitaxel as first-line chemotherapy for patients with HER2-negative metastatic breast cancer (MBC) has led to mixed results in randomized trials, with an improvement in progression-free survival (PFS) but no statistically significant overall survival (OS) benefit. Real-life data could help in assessing the value of this combination.Patients and methodsThis study aimed to describe the outcome following first-line paclitaxel with or without bevacizumab in the French Epidemiological Strategy and Medical Economics (ESME) database of MBC patients, established in 2014 by Unicancer. The primary and secondary end points were OS and PFS, respectively.ResultsFrom 2008 to 2013, 14 014 MBC patient files were identified, including 10 605 patients with a HER2-negative status. Of these, 3426 received paclitaxel and bevacizumab (2127) or paclitaxel (1299) as first-line chemotherapy. OS adjusted for major prognostic factors was significantly longer in the paclitaxel and bevacizumab group compared with paclitaxel [hazard ratio (HR) 0.672, 95% confidence interval (CI) 0.601–0.752; median survival time 27.7 versus 19.8 months]. Results were consistent in all supportive analyses (using a propensity score for adjustment and as a matching factor for nested case–control analyses) and sensitivity analyses. Similar results were observed for the adjusted PFS, favoring the combination (HR 0.739, 95% CI 0.672–0.813; 8.1 versus 6.4 months).ConclusionsIn this large-scale, real-life setting, patients with HER2-negative MBC who received paclitaxel plus bevacizumab as first-line chemotherapy had a significantly better OS and PFS than those receiving paclitaxel. Despite robust methodology, real-life data are exposed to important potential biases, and therefore, results need to be treated with caution. Our data cannot therefore support extension of current use of bevacizumab in MBC.     

Epirubicin and cyclophosphamide versus epirubicin and docetaxel as first-line therapy for women with metastatic breast cancer: final results of a randomised phase III trial

BackgroundThis randomised phase III trial was carried out to compare the efficacy and safety of epirubicin and cyclophosphamide (EC) with epirubicin and docetaxel (Taxotere) (ED) as first-line chemotherapy for metastatic breast cancer.Patients and methodsPatients (n = 240) were randomly assigned to receive either ED (epirubicin 75 mg/m² and docetaxel 75 mg/m²) or EC (epirubicin 90 mg/m² and cyclophosphamide 600 mg/m²). The primary end point was objective response rate (ORR). Secondary end points were progression-free survival (PFS), overall survival (OS), and safety.ResultsORR for patients randomly assigned to receive EC and ED were 42% and 47%, respectively (P = 0.63). Median PFS [10.1 versus 10.3 months; hazard ratio (HR) 0.98; log-rank P = 0.38] and OS (19.9 versus 30.0 months; HR 0.663; log-rank P = 0.21) were comparable in both arms. Although grade 3/4 leucopenia occurred more frequently with ED (81% versus 73%; P = 0.01), there were no significant differences in the incidence of febrile neutropenia and grade 3/4 infections. Grade 3/4 non-haematologic toxicity was infrequent in both arms. Congestive heart failure was observed in one patient in each arm.ConclusionIn this randomised trial, no differences in the efficacy study end points were observed between the two treatment arms.     

Combination of bevacizumab and 2-weekly pegylated liposomal doxorubicin as first-line therapy for locally recurrent or metastatic breast cancer. A multicenter,single-arm phase II trial (SAKK 24/06)

Background: Pegylated liposomal doxorubicin (PLD) and bevacizumab are active agents in the treatment of metastatic breast cancer (MBC). We carried out a multicenter, single-arm phase II trial to evaluate the toxicity and efficacy of PLD and bevacizumab as first-line treatment in MBC patients.Methods: Bevacizumab (10 mg/kg) and PLD (20 mg/m²) were infused on days 1 and 15 of a 4-week cycle for a maximum of six cycles. Thereafter, bevacizumab monotherapy was continued at the same dose until progression or toxicity. The primary objective was safety and tolerability, and the secondary objective was to evaluate efficacy of the combination.Results: Thirty-nine of 43 patients were assessable for the primary end point. Eighteen of 39 patients (46%, 95% confidence interval 30% to 63%) had a grade 3 toxicity. Sixteen (41%) had grade 3 palmar-plantar erythrodysesthesia, one had grade 3 mucositis, and one severe cardiotoxicity. Secondary end point of overall response rate among 43 assessable patients was 21%.Conclusions: In this nonrandomized single-arm trial, the combination of bimonthly PLD and bevacizumab in locally recurrent and MBC patients demonstrated higher than anticipated toxicity while exhibiting only modest activity. Based on these results, we would not consider this combination for further investigation in this setting.     

Non-pegylated liposomal doxorubicin combined with gemcitabine as first-line treatment for metastatic or locally advanced breast cancer. Final results of a phase I/II trial

Doxorubicin and gemcitabine are active as single agents in breast cancer, have different mechanisms of action, and mainly have non-overlapping side effects. Dose-dependent doxorubicin-related cardiac toxicity is the principal limitation in the metastatic setting. This open, multicenter, single-arm phase I/II study assessed the safety and activity of gemcitabine in combination with non-pegylated liposomal doxorubicin (Myocet), a more cardiac-friendly anthracycline, in the first-line treatment of patients with advanced breast cancer. We aimed to determine the optimal recommended dose (RD) of gemcitabine combined with Myocet in a population, with performance status >or=2 and LVEF >or=50%. A formal phase II study was performed afterwards. A total of 53 patients were recruited. Gemcitabine 900 mg/m(2) intravenously day 1 and 8 combined with Myocet 55 mg/m(2) intravenously day 1, every 21 days, was the final RD. The principal toxicity observed was hematological, and 48% of patients developed grade 3-4 neutropenia. Other toxicities were mild and infrequent, including nausea and vomiting. There were no symptomatic cardiac events despite the fact that 36% of the patients had received prior treatment with adjuvant anthracyclines. Objective responses were observed in 51.1% of 47 evaluable patients (95% CI: 36-66%), including two complete response. In addition, 14 patients (29.8%) demonstrated stable disease. The combination of Myocet and gemcitabine at the RD is safe and has encouraging clinical activity in patients with advanced breast cancer, without apparent cardiac toxicity in anthracycline-pretreated patients. These data support further development of this combination.     

Weekly docetaxel/carboplatin as primary systemic therapy for HER2-negative locally advanced breast cancer

To evaluate the effectiveness and safety of weekly docetaxel/carboplatin as primary systemic therapy (PST) for locally advanced breast cancer, we conducted a phase II study. Forty-four patients with HER2-negative locally advanced or inflammatory breast cancer (IBC) received docetaxel 35 mg/m(2) and carboplatin to an area under the curve of 2 mg/mL/min for 3 of 4 weeks over 16 weeks. After completion of PST, patients had breast surgery and then received 4 cycles of adjuvant cyclophosphamide/doxorubicin, standard radiation therapy, and, for hormone receptorpositive tumors, tamoxifen. The mean tumor size was 9.3 cm (range, 5-24 cm). Thirty-seven patients (85%) had palpable lymph nodes; 13 patients (30%) had matted or fixed nodes (N2). Eight patients had IBC. There were 11 clinical complete responses (25%) and 29 clinical partial responses (66%), resulting in 40 objective responses (91% [95% CI, 78%-96%]). Invasive disease disappeared (pathologic complete response) from the breast and axilla in 6 patients (14% [95% CI, 5%-27%]) and from the axilla in 17 patients (39% [95% CI, 24%-55%]). The only significant adverse hematologic event was grade 3 neutropenia in 4 patients (9%). The most common adverse nonhematologic events were fatigue (84% of patients) and alopecia (84%), which were usually grade 1/2. Weekly docetaxel/carboplatin appears to be active and feasible as PST in patients with large breast tumors.