MRI-guided optimisation of neoadjuvant chemotherapy duration in stage II-III HER2-positive breast cancer (TRAIN-3): a multicentre, single-arm, phase 2 study

BACKGROUND

Patients with stage II-III HER2-positive breast cancer have good outcomes with the combination of neoadjuvant chemotherapy and HER2-targeted agents. Although increasing the number of chemotherapy cycles improves pathological complete response rates, early complete responses are common. We investigated whether the duration of chemotherapy could be tailored on the basis of radiological response.

METHODS

TRAIN-3 is a single-arm, phase 2 study in 43 hospitals in the Netherlands. Patients with stage II-III HER2-positive breast cancer aged 18 years or older and a WHO performance status of 0 or 1 were enrolled. Patients received neoadjuvant chemotherapy consisting of paclitaxel (80 mg/m2 of body surface area on day 1 and 8 of each 21 day cycle), trastuzumab (loading dose on day 1 of cycle 1 of 8 mg/kg bodyweight, and then 6 mg/kg on day 1 on all subsequent cycles), and carboplatin (area under the concentration time curve 6 mg/mL per min on day 1 of each 3 week cycle) and pertuzumab (loading dose on day 1 of cycle 1 of 840 mg, and then 420 mg on day 1 of each subsequent cycle), all given intravenously. The response was monitored by breast MRI every three cycles and lymph node biopsy. Patients underwent surgery when a complete radiological response was observed or after a maximum of nine cycles of treatment. The primary endpoint was event-free survival at 3 years; however, follow-up for the primary endpoint is ongoing. Here, we present the radiological and pathological response rates (secondary endpoints) of all patients who underwent surgery and the toxicity data for all patients who received at least one cycle of treatment. Analyses were done in hormone receptor-positive and hormone receptor-negative patients separately. This trial is registered with ClinicalTrials.gov, number NCT03820063, recruitment is closed, and the follow-up for the primary endpoint is ongoing.

FINDINGS

Between April 1, 2019, and May 12, 2021, 235 patients with hormone receptor-negative cancer and 232 with hormone receptor-positive cancer were enrolled. Median follow-up was 26·4 months (IQR 22·9-32·9) for patients who were hormone receptor-negative and 31·6 months (25·6-35·7) for patients who were hormone receptor-positive. Overall, the median age was 51 years (IQR 43-59). In 233 patients with hormone receptor-negative tumours, radiological complete response was seen in 84 (36%; 95% CI 30-43) patients after one to three cycles, 140 (60%; 53-66) patients after one to six cycles, and 169 (73%; 66-78) patients after one to nine cycles. In 232 patients with hormone receptor-positive tumours, radiological complete response was seen in 68 (29%; 24-36) patients after one to three cycles, 118 (51%; 44-57) patients after one to six cycles, and 138 (59%; 53-66) patients after one to nine cycles. Among patients with a radiological complete response after one to nine cycles, a pathological complete response was seen in 147 (87%; 95% CI 81-92) of 169 patients with hormone receptor-negative tumours and was seen in 73 (53%; 44-61) of 138 patients with hormone receptor-positive tumours. The most common grade 3-4 adverse events were neutropenia (175 [37%] of 467), anaemia (75 [16%]), and diarrhoea (57 [12%]). No treatment-related deaths were reported.

INTERPRETATION

In our study, a third of patients with stage II-III hormone receptor-negative and HER2-positive breast cancer had a complete pathological response after only three cycles of neoadjuvant systemic therapy. A complete response on breast MRI could help identify early complete responders in patients who had hormone receptor negative tumours. An imaging-based strategy might limit the duration of chemotherapy in these patients, reduce side-effects, and maintain quality of life if confirmed by the analysis of the 3-year event-free survival primary endpoint. Better monitoring tools are needed for patients with hormone receptor-positive and HER2-positive breast cancer.

FUNDING

Roche Netherlands.

Abstract P3-06-01: Unleashing NK- and CD8 T cells by combining monalizumab (anti-NKG2A) and trastuzumab for metastatic HER2+ breast cancer: first results MIMOSA trial

Background Although treatment options and survival of HER2+ metastatic breast cancer (MBC) patients have greatly improved, the majority of MBC-patients still die of this disease. The relatively high levels of TILs observed in this BC subtype provide a rationale for immunomodulatory strategies, however, PD1-blockade has only shown modest response rates in this setting. While PD-1 blockade mainly acts on T cells, monalizumab targets the inhibitory immune checkpoint NKG2A which interacts with HLA-E on tumor cells, thereby unleashing NK- as well as CD8 T cells. We hypothesize that monalizumab can promote antibody-dependent cell-mediated cytotoxicity (ADCC) which is critical for trastuzumab efficacy. Clinical activity was shown in patients with head and neck cancer when monalizumab was combined with cetuximab (anti-EGFR). Here, we present the first results of the MIMOSA-trial investigating the efficacy of the novel combination monalizumab and trastuzumab in patients with HER2+ MBC. Methods In the phase II MIMOSA-trial (NTC04307329), HER2+ MBC patients were treated biweekly with 4mg/kg trastuzumab and 750mg monalizumab. Key eligibility criteria were progressive disease despite anti-HER2 therapy, had received a minimum of one and a maximum of three lines of palliative chemotherapy, had measurable disease according to RECIST1.1, and a serum LDH-level below 500U/L. Primary endpoint was objective response rate according to RECIST1.1. Secondary endpoints included clinical benefit rate (complete response CR, partial response PR or stable disease SD for at least 6 months) according to RECIST1.1, progression-free survival, overall survival and safety. Dose-limiting toxicities were continuously monitored throughout the trial and evaluated using a pre-defined Pocock-type boundary rule. Following a Simon’s two-stage design, 11 patients were included in stage I of the trial. If two or more responders were observed, further exploration is warranted in stage II. Results Between January 2021 and April 2022, eleven women of which ten are currently evaluable were enrolled in the trial. Patients received a median of two lines of prior treatment for MBC, of which 6 out of 11 patients were treated with trastuzumab emtansine (T-DM1). The majority of patients had hormone receptor positive BC (72% of the patients) and had low levels of tumor-infiltrating lymphocytes (TILs) with a median of 1% (ranging from 1% to 20%). Patients received a median of four cycles of trastuzumab and monalizumab. Treatment was well tolerated with no dose-limiting toxicities. No objective responses were observed in the first ten out of eleven evaluable patients. Therefore, MIMOSA stage I did not meet its primary endpoint, leading to discontinuation of the trial. Conclusions The novel combination of trastuzumab and monalizumab did not induce objective responses in heavily pre-treated HER2+ MBC patients.

Citation Format: Veerle Geurts, Leonie Voorwerk, Karolina Sikorska, Roberto Salgado, Koen van de Vijver, Marloes van Dongen, Inge Kemper, Ingrid A. Mandjes, Martine Heuver-mes, John Haanen, Gabe S. Sonke, Hugo Horlings, Marleen Kok. Unleashing NK- and CD8 T cells by combining monalizumab (anti-NKG2A) and trastuzumab for metastatic HER2+ breast cancer: first results MIMOSA trial [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-06-01.

Abstract OT2-15-01: COntinue the SaMe systemic therapy after local ablative therapy for Oligoprogression in metastatic breast cancer - the COSMO study

Background

Patients with metastatic breast cancer (MBC) are usually treated with palliative systemic therapy until progression or unacceptable toxicity. When progression occurs, clinicians typically switch to the next line of systemic therapy. However, this strategy might be suboptimal in case of mixed response or oligoprogression. Oligoprogression refers to a situation in which inter-lesion heterogeneity causes one or few metastatic lesions to progress while the vast majority of the metastatic burden responds to the treatment. Locally ablative treatment of the progressive lesion(s) with radiotherapy, resection or radiofrequency ablation may enable continuation of otherwise effective systemic treatment. Solid data to support this approach, however, is lacking at this moment.

Study design

The COSMO study is an investigator-initiated single-arm phase 2 study. It is intended to be a multicenter study.

Eligibility criteria

Patients with MBC and oligoprogression, defined as 1-2 progressive lesions while the majority of the metastatic burden remains stable or in remission, are eligible. Current systemic therapy must be 1st or 2nd line and patients must have responded to this systemic therapy for at least six months prior to the occurence of oligoprogression. The aberrant lesion must be amenable to locally ablative therapy. All eligibility criteria may be found in table 1: eligibility criteria. Aim To investigate efficacy of local ablation of aberrant lesions combined with continuation of the same systemic therapy in patients with oligoprogression of MBC.

Primary endpoint:

Progression-free survival rate at six months (PFS-6).

Secondary endpoints:

- PFS

- Overall survival

- Time to next line of systemic therapy

Primary and secondary endpoints will also be stratified by localization of progressive lesion and BC subtype (ER+/HER2- vs. HER2+ vs. TN).

- Local control rate of lesion treated with LAT at 12 months

- Complications due to LAT

- Quality of life

- Incidence of visceral crisis

Exploratory endpoints:

- Biomarkers, including receptor (ER/PR/HER2), PD-L1 and gene expression patterns in biopsies from progressive and responding lesions

- Prognostic value of ctDNA at oligoprogression and during the course of treatment

Statistical methods

An A’hern design was chosen to conduct this study. As null-hypothesis (H0), PFS-6 rate ≤ 25% is set. The alternative hypothesis (H1) is PFS-6-rate ≥ 40%. Hypotheses were set to meet criteria for clinical significance, as stated by experts in the field. Setting one-sided α = 0.05 and a desirable power=95%, 107 evaluable patients are needed. To account for 10% of the patients to be unevaluable, 118 included patients are needed. An early stopping rule for safety is applicable: if out of the first 45 patients ≥4 of these patients have developed visceral crisis, the study will be closed early.

Accrual

Start: July 2022

Target: 118 patients

Estimated accrual time: 2-3 years

Further information

Corresponding author: c.almekinders@nki.nl

Clinicaltrials.gov identifier: NCT05301881

This study is funded by the Maarten van der Weijden foundation.

This study was developed during the 21st EORTC/ESMO/AACR workshop on methods in clinical cancer research (MCCR).

Table 1. Eligibility criteria.

Citation Format: Cornelia AM Almekinders, Tessa G Steenbruggen, Ingrid A. Mandjes, Marta Lopez-Yurda, Monique EMM Bos, Terry G Wiersma, Gabe S. Sonke. COntinue the SaMe systemic therapy after local ablative therapy for Oligoprogression in metastatic breast cancer - the COSMO study [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr OT2-15-01.

Abstract PD18-06: Image-guided optimization of neoadjuvant chemotherapy duration in stage II and III HER2-positive breast cancer: radiologic and pathologic complete response (pCR) rates in the multicenter phase 2 TRAIN-3 study (BOOG 2018-01)

Background pCR rates in stage II – III HER2-positive breast cancer have greatly improved since the addition of HER2 targeted agents to neoadjuvant chemotherapy and are associated with excellent long-term survival. While longer treatment regimens increase pCR rate, early complete responses are also common. We evaluated an image-guided approach to tailor chemotherapy duration based on the identification of early complete responders.

Methods 45 hospitals across the Netherlands participated in the phase 2 TRAIN-3 trial. Patients received neoadjuvant systemic treatment consisting of paclitaxel, trastuzumab, carboplatin and pertuzumab (PTC-Ptz). Response to treatment was monitored every three cycles and patients were referred for surgery in case of a radiologic complete response (rCR) or after a maximum of 9 cycles. RCR was defined as the absence of pathological enhancement on MRI breast plus negative vacuum assisted core biopsies in case of hormone-receptor positive (HR+) tumors. In addition, negative fine needle aspiration or lymph node biopsy was required in patients with nodal involvement at baseline. The primary endpoint was 3-year event-free survival (EFS). Here, we report locally assessed rCR and pCR rates after 3, 6 and 9 cycles, the negative predictive value of rCR assessment and the incidence of adverse events (AEs). Analyses are stratified by HR-status.

Results We included 467 patients between April 2019 and May 2021. Median age was 51 years, 69% had stage II disease and 232 had HR+ tumors. 33.6% of HR- patients and 15.5% of HR+ patients achieved pCR after 3 cycles of PTC-Ptz (see table). The NPV was higher in HR- patients and independent of the number of cycles. AE evaluation is currently ongoing.

Conclusion Three cycles of PTC-Ptz induce an early pCR in one in three HR- and one in six HR+ tumors in patients with stage II-III HER2+ breast cancer. Dynamic contrast enhanced MRI-based response evaluation identifies these patients with ±87% certainty in HR- disease and ±58% in HR+ disease. Continuation of PTC-Ptz after 6 cycles further improves pCR rates and can be considered to reduce the need for adjuvant T-DM1. Efficacy and safety of this image-guided approach to tailor treatment duration need to be confirmed with follow-up in EFS and OS analyses.

Table 1: Cumulative rCR & pCR according to HR-status *Including patients who underwent surgery for other reasons than rCR

Citation Format: Anna van der Voort, Mette S. van Ramshorst, Rob Kessels, Ingrid A. Mandjes, Inge Kemper, Mariëtte J. Agterof, Wim A. van der Steeg, Joan B. Heijns, Marlies L. van Bekkum, Ester J. Siemerink, Philomeen M. Kuijer, Astrid Scholten, Jelle Wesseling, Marie-Jeanne T.F.D. Vrancken Peeters, Ritse M. Mann, Gabe S. Sonke. Image-guided optimization of neoadjuvant chemotherapy duration in stage II and III HER2-positive breast cancer: radiologic and pathologic complete response (pCR) rates in the multicenter phase 2 TRAIN-3 study (BOOG 2018-01) [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr PD18-06.

Three-Year Follow-up of Neoadjuvant Chemotherapy With or Without Anthracyclines in the Presence of Dual ERBB2 Blockade in Patients With ERBB2-Positive Breast Cancer: A Secondary Analysis of the TRAIN-2 Randomized, Phase 3 Trial

Importance

Primary analysis of the TRAIN-2 study showed high pathologic complete response rates after neoadjuvant chemotherapy with or without anthracyclines plus dual ERBB2 (formerly HER2) blockade.

Objective

To evaluate 3-year event-free survival (EFS) and overall survival (OS) of an anthracycline-free and anthracycline-containing regimen with dual ERBB2 blockade in patients with stage II and III ERBB2-positive breast cancer.

Design, Setting, and Participants

A total of 438 patients with stage II and III ERBB2-positive breast cancer were enrolled in this randomized, clinical, open-label phase 3 trial across 37 hospitals in the Netherlands from December 9, 2013, until January 14, 2016. Follow-up analyses were performed after a median follow-up of 48.8 months (interquartile range, 44.1-55.2 months). Analysis was performed on an intention-to-treat basis.

Interventions

Participants were randomly assigned on a 1:1 basis, stratified by age, tumor stage, nodal stage, and estrogen receptor status, to receive 3 cycles of fluorouracil (500 mg/m2), epirubicin (90 mg/m2), and cyclophosphamide (500 mg/m2), followed by 6 cycles of paclitaxel and carboplatin or 9 cycles of paclitaxel (80 mg/m2 days 1 and 8) and carboplatin (area under the concentration-time curve, 6 mg/mL/min). Both groups received trastuzumab (6 mg/kg; loading dose 8 mg/kg) and pertuzumab (420 mg intravenously; loading dose 840 mg) every 3 weeks.

Main Outcomes and Measures

Three-year EFS, OS, and safety.

Results

A total of 438 women were randomized, with 219 per group (anthracycline group, median age, 49 years [interquartile range, 43-55 years]; and nonanthracycline group, median age, 48 years [interquartile range, 43-56 years]). A total of 23 EFS events (10.5%) occurred in the anthracycline group and 21 EFS events (9.6%) occurred in the nonanthracycline group (hazard ratio, 0.90; 95% CI, 0.50-1.63; favoring nonanthracyclines). Three-year EFS estimates were 92.7% (95% CI, 89.3%-96.2%) in the anthracycline group and 93.6% (95% CI, 90.4%-96.9%) in the nonanthracycline group and 3-year OS estimates were 97.7% (95% CI, 95.7%-99.7%) in the anthracycline group and 98.2% (95% CI, 96.4%-100%) in the nonanthracycline group. The results were irrespective of hormone receptor and nodal status. A decline in left ventricular ejection fraction of 10% or more from baseline to less than 50% was more common in patients who received anthracyclines than those who did not (17 of 220 [7.7%] vs 7 of 218 [3.2%]; P = .04). Two patients treated with anthracyclines developed acute leukemia.

Conclusions and Relevance

This follow-up analysis of the TRAIN-2 study shows similar 3-year EFS and OS estimates with or without anthracyclines in patients with stage II and III ERBB2-positive breast cancer. Anthracycline use is associated with increased risk of febrile neutropenia, cardiotoxic effects, and secondary malignant neoplasms.

Trial Registration

ClinicalTrials.gov Identifier: NCT01996267.

Three-year follow-up of neoadjuvant chemotherapy with or without anthracyclines in the presence of dual HER2-blockade for HER2-positive breast cancer (TRAIN-2): A randomized phase III trial

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Background: The multicenter phase III TRAIN-2 study showed high pathological complete response (pCR) rates after neoadjuvant chemotherapy with and without anthracylines plus dual HER2-blockade in stage II-III HER2-positive breast cancer patients (67% vs 68%, p = 0.95) (NCT01996267). Here we report 3-year efficacy and safety outcomes. Methods: Patients were randomly assigned (1:1) to receive 3 cycles 5-fluoruoracil (500mg/m2), epirubicin (90mg/m2), and cyclophosphamide (500mg/m2) followed by 6 cycles paclitaxel (80mg/m2 day 1 and 8) and carboplatin (AUC = 6mg/ml·min) (FEC-PC) or 9 cycles paclitaxel and carboplatin (PC). Both regimens were combined with trastuzumab (T; 6mg/kg, loading dose 8mg/kg) and pertuzumab (Ptz; 420mg, loading dose 840mg). Patients completed one year of trastuzumab, radiotherapy and endocrine therapy as indicated. The primary endpoint pCR was previously reported. Secondary efficacy endpoints reported here are event-free-survival (EFS) defined as time from randomization to first event (disease progression resulting in inoperability, recurrence [contralateral DCIS excluded], secondary primary malignancies, or death) and overall survival (OS), both in the intention-to-treat population. Safety endpoints are reported for patients treated with at least one dose of study medication. Results: 438 patients were randomized (219/arm) and evaluable for long-term efficacy endpoints. After a median follow-up of 48.8 months 23 EFS events occurred in the FECT-PTC-Ptz-arm and 21 in the PTC-Ptz-arm (HR 0.90; 95% CI 0.50-1.63). Three-year EFS estimates were 92.7% (95% CI: 89.3-96.2) for FECT-PTC-Ptz and 93.6% (95% CI: 90.4-96.9) for PTC-Ptz. Three-year OS estimates were 97.7% (95% CI: 95.7-99.7) for FECT-PTC-Ptz and 98.2% (95% CI: 96.4-100) for PTC-Ptz. These results were irrespective of hormone receptor and nodal status. LVEF decline ≥10% from baseline and < 50% was more common in patients who received anthracyclines than in the PTC-Ptz arm (8.6% vs. 3.2%, p = 0.021). Two patients in the FECT-PTC-Ptz arm developed acute leukemia. No other new safety concerns were seen. Conclusions: The 3-year follow-up of the TRAIN-2 study confirms the results of the primary outcome that anthracylines do not improve efficacy and are associated with clinically relevant toxicity. A neoadjuvant carboplatin-taxane based regimen with dual HER2-blockade can be considered in all stage II-III breast cancer patients, regardless of hormone receptor and nodal status. Clinical trial information: NCT01996267 .

Neoadjuvant chemotherapy with or without anthracyclines in the presence of dual HER2 blockade for HER2-positive breast cancer (TRAIN-2): a multicentre, open-label, randomised, phase 3 trial

BACKGROUND

The optimal chemotherapy backbone for dual HER2 blockade in the neoadjuvant setting for early breast cancer is unknown. We investigated whether the addition of anthracyclines would improve pathological complete response compared with a carboplatin-taxane regimen, when given in combination with the HER2-targeted agents trastuzumab and pertuzumab.

METHODS

The TRAIN-2 study is an open-label, randomised, controlled, phase 3 trial being done in 37 hospitals in the Netherlands. We recruited patients aged 18 years or older with previously untreated, histologically confirmed stage II-III HER2-positive breast cancer. Patients were randomly allocated using central randomisation software (1:1 ratio) with minimisation without a random component, stratified by tumour stage, nodal stage, oestrogen receptor status, and age, to receive 5-fluorouracil (500 mg/m²), epirubicin (90 mg/m²), and cyclophosphamide (500 mg/m²) every 3 weeks for three cycles followed by paclitaxel (80 mg/m² on days 1 and 8) and carboplatin (area under the concentration-time curve [AUC] 6 mg/mL per min on day 1 or optionally, as per hospital preference, AUC 3 mg/mL per min on days 1 and 8) every 3 weeks for six cycles, or to receive nine cycles of paclitaxel and carboplatin at the same dose and schedule as in the anthracycline group. Patients in both study groups received trastuzumab (6 mg/kg, loading dose 8 mg/kg) and pertuzumab (420 mg, loading dose 840 mg) concurrently with all chemotherapy cycles. The primary endpoint was the proportion of patients who achieved a pathological complete response in breast and axilla (ypT0/is ypN0) in the intention-to-treat population. Safety was analysed in patients who received at least one treatment cycle according to actual treatment received. This trial is registered with ClinicalTrials.gov, number NCT01996267, and follow-up for long-term outcome is ongoing.

FINDINGS

Between Dec 9, 2013, and Jan 14, 2016, 438 patients were enrolled and randomly assigned to the two treatment groups (219 patients to each group), of whom 418 were evaluable for the primary endpoint (212 in the anthracycline group and 206 in the non-anthracycline group). The median follow-up for all patients was 19 months (IQR 16-23 months). A pathological complete response was recorded in 141 (67%, 95% CI 60-73) of 212 patients in the anthracycline group and in 140 (68%, 61-74) of 206 in the non-anthracycline group (p=0·95). One patient randomly allocated to the non-anthracycline group did receive anthracyclines and was thus included in the anthracycline group for safety analyses; therefore, for the safety analyses there were 220 patients in the anthracycline group and 218 in the non-anthracycline group. Serious adverse events were reported in 61 (28%) of 220 patients in the anthracycline group and in 49 (22%) of 218 in the non-anthracycline group. The most common adverse events of any cause were grade 3 or worse neutropenia (in 131 [60%] of 220 patients in the anthracycline group vs 118 [54%] of 218 in the non-anthracycline group), grade 3 or worse diarrhoea (26 [12%] vs 37 [18%]), and grade 2 or worse peripheral neuropathy (66 [30%] vs 68 [31%]), with no substantial differences between the groups. Grade 3 or worse febrile neutropenia was more common in the anthracycline group than in the non-anthracycline group (23 [10%] vs three [1%], p<0·0001). Symptomatic left ventricular systolic dysfunction was rare in both groups (two [1%] of 220 vs 0 of 218). One patient in the anthracycline group died because of a pulmonary embolism, which was possibly treatment related.

INTERPRETATION

In view of the high proportion of pathological complete responses recorded in both groups and the fact that febrile neutropenia was more frequent in the anthracycline group, omitting anthracyclines from neoadjuvant treatment regimens might be a preferred approach in the presence of dual HER2 blockade in patients with early HER2-positive breast cancer. Long-term follow-up is required to confirm these results.

FUNDING

Roche Netherlands.

A phase III trial of neoadjuvant chemotherapy with or without anthracyclines in the presence of dual HER2-blockade for HER2+ breast cancer: The TRAIN-2 study (BOOG 2012-03)

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Background: Neoadjuvant chemotherapy with dual HER2 blockade boosts pathologic complete response (pCR) rates in HER2+ breast cancer. The optimal chemotherapy backbone in this setting is unknown. We conducted a multicenter phase III trial to study whether anthracyclines would improve outcome compared to a carboplatin-taxane regimen (NCT01996267). Methods: We randomly assigned (1:1) patients with stage II-III HER2+ breast cancer to receive 9 cycles paclitaxel (80mg/m2 day 1 and 8) and carboplatin (AUC = 6mg/ml·min) (arm A) or 3 cycles 5-fluoruoracil (500mg/m2), epirubicin (90mg/m2), and cyclophosphamide (500mg/m2) followed by 6 cycles paclitaxel and carboplatin (arm B). Both arms received trastuzumab (6mg/kg, loading dose 8mg/kg) and pertuzumab (420mg, loading dose 840mg) concurrent with all chemotherapy cycles, and cycles were repeated every 3 weeks. The primary endpoint was pCR in breast and axilla (ypT0/is,ypN0). Results: 438 patients were included and 418 (arm A 206 vs arm B 212) were evaluable for the primary endpoint. The pCR rate did not differ between arms (arm A 68% [95% CI 61-74] vs arm B 67% [95% CI 60-73], p = 0.75). Hormone receptor (HR) negative tumors had significantly higher pCR rates (87% vs 54%, p < 0.0001), but we found no evidence for treatment-by-HR interaction (p = 0.23). Common adverse events grade ≥3 were neutropenia (arm A 53% vs arm B 57%, p = 0.34), febrile neutropenia (arm A 2% vs arm B 11%, p = 0.0001), and diarrhea (arm A 17% vs arm B 12%, p = 0.14). Neuropathy grade ≥2 was common in both arms (arm A 31% vs arm B 29%, p = 0.83), while left ventricular ejection fraction (LVEF) decline grade ≥2 (defined as ≥10% decline from baseline or LVEF < 50%) was more common in arm B (arm A 18% vs arm B 29%, p = 0.007). Symptomatic left ventricular systolic dysfunction was rare ( < 1%) in both arms. Conclusions: Anthracyclines increase the incidence of febrile neutropenia and grade ≥2 LVEF decline, but do not improve pCR rate in the contemporary neoadjuvant treatment of HER2+ breast cancer with dual HER2 blockade. Therefore, we currently favor a carboplatin-taxane based regimen. Follow-up is required to confirm these results with regard to long-term outcome. Clinical trial information: NCT01996267.

Paclitaxel, carboplatin, and trastuzumab in a neo-adjuvant regimen for HER2-positive breast cancer

To evaluate a nonanthracycline-containing regimen consisting of 24 weekly administrations of paclitaxel, carboplatin, and trastuzumab as neo-adjuvant therapy for human epidermal growth factor receptor 2 (HER2)-positive breast cancer. Patients with stage II or III breast cancer, including inflammatory disease, with HER2 overexpression (immunohistochemistry and/or fluorescent in situ hybridization) were treated with 24 weekly administrations of paclitaxel 70 mg/m(2) , carboplatin AUC = 3 mg/mL/minute, and trastuzumab 2 mg/kg (loading dose 4 mg/kg). In cycles 7, 8, 15, 16, 23, and 24, only trastuzumab was given. The primary end point was pathologic complete response (pCR) in both breast and axilla. Of 61 evaluable patients, 61% had stage II disease and 75% were node-positive. The median NRI (Neoadjuvant Response Index, a measure of the degree of downstaging by chemotherapy) of all patients was 0.86. Twenty-seven (44%) had a NRI of 1.0, which corresponds to pCR in breast and lymph nodes. The most commonly reported grade 3/4 toxicities were neutropenia (72%) and thrombocytopenia (36%). Dose reduction was necessary in 51% of the patients. A weekly carboplatin-paclitaxel-trastuzumab neo-adjuvant regimen is highly active in HER2-positive breast cancer with an acceptable toxicity profile. A multicenter phase 2 trial has recently reached its accrual target and will serve as a basis for a subsequent randomized phase 3 study comparing this regimen to a similar regimen preceded by anthracyclines.

P3-14-17: Paclitaxel, Carboplatin, and Trastuzumab in a Neoadjuvant Regimen for HER2−Positive Breast Cancer: The TRAIN Study

Background: Treatment with trastuzumab is highly active in HER2 positive breast cancer, although cardiotoxicity is a well known side effect. The cardiotoxicity of trastuzumab may be aggravated by combined treatment with anthracyclines. Consequently, treatment with trastuzumab is often delayed pending the administration of anthracyclines. Both in vitro and in vivo data suggest that trastuzumab synergizes with a range of chemotherapeutic drugs, including taxoid drugs and carboplatin. In addition, prolonged pre-operative treatment leads to higher pathologic complete remission (pCR) rates. We report the results of a fase 2 trial integrating trastuzumab at the start of a non-anthracycline containing weekly paclitaxel-carboplatin based neo-adjuvant chemotherapy regimen in HER2−positive breast cancer. Patients and methods: One-hundred patients with stage II or III breast cancer, including inflammatory disease, with HER2 overexpression (immunohistochemistry and/or in situ hybridization) were treated with 24 weekly administrations of paclitaxel 70 mg/m2, carboplatin AUC=3 mg.ml-1.min, and trastuzumab 2 mg/kg (loading dose 4 mg/kg). In cycles 7, 8, 15, 16, 23, and 24 only trastuzumab was given. The primary end point was pathologic complete response (pCR) in both breast and axilla. The trial was preceded by an initial pilot cohort of 55 patients treated with the same regimen.

Results: Final efficacy and safety results of all patients included in the phase 2 trial will be reported at the meeting. In the pilot cohort of 55 similarly treated patients, 33% had stage II disease, 69% was clinically node positive, and 49% was ER and PgR negative. Twenty-four patients (41%) had a pCR in breast and lymph nodes. pCR in ER negative patients was 67%, pCR in ER positive patients was 21%. The most commonly reported grade 3/4 toxicities were neutropenia (30%) and thrombocytopenia (27%). Dose reduction was required in 24% of the patients. Grade 3/4 left ventricular systolic dysfunction was not observed.

Conclusion: A weekly carboplatin-paclitaxel-trastuzumab neo-adjuvant regimen is highly active in HER2 positive breast cancer with a good safety profile. A subsequent multicenter phase 3 trial will compare this regimen to a similar 16 week regimen preceded by 4 cycles of anthracyclines plus cyclophosphamide.

The study protocol was developed at the joint ECCO-AACR-EORTC-ESMO Workshop on Methods in Clinical Cancer Research in Flims, Switserland.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-14-17.

Phase I clinical and pharmacokinetic study of PNU166945, a novel water-soluble polymer-conjugated prodrug of paclitaxel

Intravenous administration of paclitaxel is hindered by poor water solubility of the drug. Currently, paclitaxel is dissolved in a mixture of ethanol and Cremophor EL; however, this formulation (Taxol) is associated with significant side effects, which are considered to be related to the pharmaceutical vehicle. A new polymer-conjugated derivative of paclitaxel, PNU166945, was investigated in a dose-finding phase I study to document toxicity and pharmacokinetics. A clinical phase I study was initiated in patients with refractory solid tumors. PNU16645 was administered as a 1-h infusion every 3 weeks at a starting dose of 80 mg/m(2), as paclitaxel equivalents. Pharmacokinetics of polymer-bound and released paclitaxel were determined during the first course. Twelve patients in total were enrolled in the study. The highest dose level was 196 mg/m(2), at which we did not observe any dose-limiting toxicities. Hematologic toxicity of PNU166945 was mild and dose independent. One patient developed a grade 3 neurotoxicity. A partial response was observed in one patient with advanced breast cancer. PNU166945 displayed a linear pharmacokinetic behavior for the bound fraction as well as for released paclitaxel. The study was discontinued prematurely due to severe neurotoxicity observed in additional rat studies. The presented phase I study with PNU166945, a water-soluble polymeric drug conjugate of paclitaxel, shows an alteration in pharmacokinetic behavior when paclitaxel is administered as a polymer-bound drug. Consequently, the safety profile may differ significantly from standard paclitaxel.

Phase II trial of topically applied miltefosine solution in patients with skin-metastasized breast cancer

Skin deposits from breast cancer can present serious therapeutic problems, especially when resistant to conventional therapy. Topical application of a cytotoxic drug may represent an attractive new treatment modality devoid of major systemic toxicity. Miltefosine was selected because of its efficacy in breast cancer models. A mixture of alkylated glycerols of various chain lengths and water was used as the pharmaceutical vehicle to dissolve and to further facilitate tissue penetration of miltefosine. In our Institute a phase II study was performed to determine the efficacy and tolerability of topically applied miltefosine in patients with cutaneous metastases from breast cancer. Thirty-three patients in total entered the trial. A 6% miltefosine solution was applied once daily in the first week and twice daily in the following weeks. The planned minimum treatment duration was 8 weeks. We found an overall response rate of 43% for 30 evaluable patients, composed of 23% complete response and 20% partial response. The median response duration was 18 weeks, range 8-68. Toxicity consisted mainly of localized skin reactions, which could be controlled by a paraffin-based skin cream and, where appropriate, by dose modification. No systemic toxicities were observed. We conclude that topical miltefosine is an effective treatment modality in patients with skin metastases from breast cancer.

Phase I and pharmacological study of sequential intravenous topotecan and oral etoposide

We performed a phase I and pharmacological study to determine the maximum tolerated dose (MTD) and dose-limiting toxicities (DLT) of a cytotoxic regimen of the novel topoisomerase I inhibitor topotecan in combination with the topoisomerase II inhibitor etoposide, and to investigate the clinical pharmacology of both compounds. Patients with advanced solid tumours were treated at 4-week intervals, receiving topotecan intravenously over 30 min on days 1-5 followed by etoposide given orally twice daily on days 6-12. Topotecan-etoposide dose levels were escalated from 0.5/20 to 1.0/20, 1.0/40, and 1.25/40 (mg m-2 day-1)/(mg bid). After encountering DLT, additional patients were treated at 3-week intervals with the topotecan dose decreased by one level to 1.0 mg m-2 and etoposide administration prolonged from 7 to 10 days to allow further dose intensification. Of 30 patients entered, 29 were assessable for toxicity in the first course and 24 for response. The DLT was neutropenia. At doses of topotecan-etoposide 1.25/40 (mg m-2)/(mg bid) two out of six patients developed neutropenia grade IV that lasted more than 7 days. Reduction of the treatment interval to 3 weeks and prolonging etoposide dosing to 10 days did not permit further dose intensification, as a time delay to retreatment owing to unrecovered bone marrow rapidly emerged as the DLT. Post-infusion total plasma levels of topotecan declined in a biphasic manner with a terminal half-life of 2.1 +/- 0.3 h. Total body clearance was 13.8 +/- 2.7 l h-1 m-2 with a steady-state volume of distribution of 36.7 +/- 6.2 l m-2. N-desmethyltopotecan, a metabolite of topotecan, was detectable in plasma and urine. Mean maximal concentrations ranged from 0.23 to 0.53 nmol l-1, and were reached at 3.4 +/- 1.0 h after infusion. Maximal etoposide plasma concentrations of 0.75 +/- 0.54 and 1.23 +/- 0.57 micromol l-1 were reached at 2.4 +/- 1.2 and 2.3 +/- 1.0 h after ingestion of 20 and 40 mg respectively. The topotecan area under the plasma concentration vs time curve (AUC) correlated with the percentage decrease in white blood cells (WBC) (r2 = 0.70) and absolute neutrophil count (ANC) (r2 = 0.65). A partial response was observed in a patient with metastatic ovarian carcinoma. A total of 64% of the patients had stable disease for at least 4 months. The recommended dose for use in phase II clinical trials is topotecan 1.0 mg m-2 on days 1-5 and etoposide 40 mg bid on days 6-12 every 4 weeks.

High-dose paclitaxel with granulocyte colony-stimulating factor in patients with advanced breast cancer refractory to anthracycline therapy: a European Cancer Center trial

Paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) is a novel cytostatic agent that has shown interesting antitumor activity in patients with advanced breast cancer. Depending on variable patient characteristics and amount and type of prior therapy, as well as the applied dose and schedule of paclitaxel, response rates have varied from 13% to 62%. However, optimal dose and schedule are still unknown. We studied a high-dose (250 to 300 mg/m2) 3-hour paclitaxel infusion schedule in a poor prognostic group of breast cancer patients who progressed or relapsed while taking anthracyclines. This regimen was given every 3 weeks. Twenty-one of the 36 patients studied had increased liver enzymes and 18 had documented liver metastases. The objective response rate was only 6%, but response rate by disease site indicated that soft tissue lesions responded in 30% of cases. For a better comparison with other reported data a uniform definition of "anthracycline refractory" is needed. Neuropathy, which was found to be dose limiting, and arthralgia/myalgia syndrome were the most frequently occurring toxicities. Both severe myelosuppression (and infections) and severe diarrhea and mucositis were reported more frequently in patients with liver dysfunction. As higher peak levels, increased areas under the concentration time curves, and longer times during which plasma concentrations were above the threshold level of 0.1 mumol/L were found in patients with elevated liver enzymes, a correlation with the observed toxicities is assumed. Further pharmacodynamic studies in such patients receiving a 3-hour infusion seem warranted.

Toxicity grading systems. A comparison between the WHO scoring system and the Common Toxicity Criteria when used for nausea and vomiting

BACKGROUND

The Common Toxicity Criteria adopted by the NCI in the USA for grading toxicity in cancer clinical trials have been compared to the WHO scoring system which is still in use in Europe.

PATIENTS & METHODS

Sixty-six patients undergoing emetic chemotherapy at the Netherlands Cancer Institute completed questionnaires, 32 according to the WHO criteria and 34 to the Common Toxicity Criteria, on the severity, frequency and duration of gastro-intestinal toxicity. Their answers were then compared to the scores coded by research nurses and physicians. The nurses coded acute toxicity when the patients were discharged, and the doctors coded overall toxicity when the patients returned for the subsequent course of chemotherapy. To evaluate the coding systems, an estimate was made of the percentage agreement between the patients' answers and the nurses' and doctors' ratings.

RESULTS

The percentage agreement of the Common Toxicity Criteria with the patients' own experiences of nausea and vomiting was considerably better than that of the WHO score. The Gamma statistic confirmed this. The Common Toxicity Criteria have now been adopted for grading toxicity in studies of the Early Clinical Trials Group of the EORTC and are recommended for use in other clinical trials.