The PARTNER trial of neoadjuvant olaparib in triple-negative breast cancer

PARTNER is a prospective, phase II-III, randomised controlled clinical trial, which recruited patients with Triple Negative Breast Cancer (TNBC)1,2, who were gBRCA wild type (gBRCAwt)3. Patients (n=559) were randomised on a 1:1 basis to neoadjuvant carboplatin with paclitaxel +/- olaparib 150mg twice daily, days 3 to 14, for 4 cycles (gap schedule olaparib, research arm) followed by 3 cycles of anthracycline chemotherapy before surgery. The primary endpoint was pathological complete response (pCR)4, and secondary endpoints included event-free survival (EFS), and overall survival (OS)5. pCR was achieved in 51% in the research arm and 52% in the control arm (p=0.753). Estimated EFS at 36 months in research and control arms were 80% and 79% (log-rank p>0.9); OS were 90% and 87.2% (log-rank p=0.8) respectively. In patients with pCR, estimated EFS at 36 months was 90%, and with non-pCR was 70% (log-rank p < 0.001) and OS was 96% and 83% (log-rank p < 0.001) respectively. Neo-adjuvant olaparib did not improve pCR rates, EFS or OS when added to carboplatin/paclitaxel and anthracycline chemotherapy in patients with TNBC (gBRCAwt). This is in marked contrast to the major benefit of olaparib (gap schedule) in those with gBRCA pathogenic variants (gBRCAm) which is reported separately (gBRCAm article). ClinicalTrials.gov ID NCT03150576.

Abstract CT562: PARTNER: Randomised, phase II/III trial to evaluate the safety and efficacy of the addition of Olaparib to Platinum-based neoadjuvant chemotherapy in triple negative and/or germline BRCA mutated breast cancer patients

Background: Triple Negative Breast Cancers (TNBC) are a biologically diverse and aggressive subgroup lacking targeted therapy. TNBC and Germline BRCA (gBRCA) breast cancer share certain phenotypic and molecular similarities, with gBRCA mutations seen in 10% to 20% of TNBC patients. Homologous recombination deficient tumours, especially those caused by germline or somatic BRCA mutations, are thought to be particularly sensitive to PARP inhibitors.

Aim: To establish if the addition of Olaparib to neoadjuvant Platinum-based chemotherapy in the treatment of basal TNBC and/or gBRCA breast cancer is safe and increases efficacy.

Trial design: 3-stage open label randomised phase II/III trial of neoadjuvant Paclitaxel and Carboplatin +/- Olaparib, followed by clinicians' choice of Anthracycline regimen. Stages 1 and 2: Randomisation (1:1:1) to control (3-weekly carboplatin AUC5/weekly with paclitaxel 80mg/m2 for 4 cycles), or to one of two research arms. These use an identical chemotherapy regimen and also include different treatment schedules of Olaparib 150mg BD for 12 days. Stage 3: Randomisation (1:1) to either the control or research arm chosen following stage 2. End-points: Stage 1: Safety; Stage 2: Schedule selection based on pCR rate and Olaparib completion rate using a “pick-the-winner” design. Stage 3: pCR rate. This trial includes an optional pathway (PARTNERING) for patients with evidence of residual disease after six chemotherapy cycles. This aims to establish if the addition of new agents (ATR inhibitor and PD-L1 inhibitor) improves treatment response.

Eligibility criteria: Aged 16-70; histologically confirmed invasive breast cancer; ER-negative, HER2-negative with TNBC basal phenotype or gBRCA positive, HER2-negative irrespective of hormone status; stage T1-4 N0-2; performance status 0-1; treatment within 6 weeks of diagnostic biopsy; biomarker scores: TILs, CK 5/6, EGFR +/- AR.

Statistical methods: The recruitment of TNBC non-gBRCA and gBRCA patients is independent. Enrichment design is applied with an overall significance level 0.05(α) and 80% power. A minimum of 780 patients will be included to detect an absolute improvement of 15% (all patients and TNBC non-gBRCA cohort) and 20% (gBRCA patients) by combining Olaparib with Platinum based chemotherapy. A minimum of 478 TNBC non-gBRCA and 188 gBRCA patients will be recruited. Each PARTNERING cohort will consist of 15 patients.

Current Enrollment: Since May 2016, 756 patients from 30 sites have been enrolled. Stages 1 and 2 are completed. An IDSMC review identified no safety concerns and Research Arm 2 was selected. This arm involves Olaparib administration on days 3-14. Stage 3 Phase I (recruitment of non-gBRCA and gBRCA patients) completed in December 2021. Stage 3 Phase II (recruitment of gBRCA patients only) remains open to patients to UK and internationally. 5 patients have been enrolled in PARTNERING.

ClinicalTrials.gov Identifier: NCT03150576

Citation Format: Lynsey Drewett, Karen A. Pinilla, Louise Grybowicz, Jerome Wulff, Alimu Dayimu, Nikolaos Demiris, Rebecca Lucey, Anne-Laure Vallier, Wendi Qian, Andrea Machin, PARTNER Research Team, Karen McAdam, Rebecca Roylance, Ellen R. Copson, Anne Armstrong, Nicola Levitt, Elena Provenzano, Marc Tischkowitz, Emma McMurtry, Helena Earl, Jean E. Abraham. PARTNER: Randomised, phase II/III trial to evaluate the safety and efficacy of the addition of Olaparib to Platinum-based neoadjuvant chemotherapy in triple negative and/or germline BRCA mutated breast cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT562.

PARTNER: A randomized, phase II/III trial to evaluate the safety and efficacy of the addition of olaparib to platinum-based neoadjuvant chemotherapy in patients with triple-negative and/or germline BRCA-mutated breast cancer

TPS619

Background: Triple negative breast cancers (TNBCs) are a biologically diverse and aggressive subgroup lacking targeted therapy. TNBC and germline BRCA (gBRCA) breast cancer share certain phenotypic and molecular similarities, with gBRCA mutations seen in 10% to 20% of TNBC patients. Homologous recombination-deficient tumors, especially those caused by germline or somatic BRCA mutations, are thought to be particularly sensitive to PARP inhibitors. Methods: This is a 3-stage open-label randomized phase II/III trial of neoadjuvant paclitaxel and carboplatin +/- olaparib, followed by clinicians' choice of anthracycline regimen. The aim is to establish whether the addition of olaparib to neoadjuvant platinum-based chemotherapy in the treatment of basal TNBC and/or gBRCA breast cancer is safe and increases efficacy. In stages 1 and 2, all patients receive 4 cycles of 3-weekly carboplatin AUC5/weekly paclitaxel 80mg/m2. They are randomly assigned 1:1:1 to a control arm, or to one of two research arms. These research arms include different treatment schedules of olaparib 150 mg BD for 12 days. In stage 3, patients are randomly assigned 1:1 to either the control or research arm chosen following stage 2. The primary endpoints are: Stage 1: Safety; Stage 2: Schedule selection based on pCR rate and olaparib completion rate using a “pick-the-winner” design. Stage 3: pCR rate. Key eligibility criteria are age 16-70; histologically confirmed invasive breast cancer; ER-negative, HER2-negative with TNBC basal phenotype or gBRCA positive, HER2-negative irrespective of hormone status; stage T1-4 N0-2; performance status 0-1; treatment within 6 weeks of diagnostic biopsy; biomarker scores: TILs, CK 5/6, EGFR +/- AR. The recruitment of TNBC non-gBRCA and gBRCA patients is independent. Enrichment design is applied with an overall significance level 0.05(α) and 80% power. A minimum of 780 patients will be included to detect an absolute improvement of 15% (all patients) and 20% (gBRCA patients) by combining olaparib with platinum-based chemotherapy. This trial includes an optional pathway called PARTNERING for patients with residual disease after six chemotherapy cycles. This aims to establish if adding new agents (ATR inhibitor and PD-L1 inhibitor) improves treatment response. Each cohort will consist of 15 patients. Since May 2016, 756 patients from 30 sites have been enrolled. An IDSMC review following stages 1 and 2 identified no safety concerns and Research Arm 2 was selected (olaparib administration on days 3-14). Stage 3 phase I (recruitment of non-gBRCA and gBRCA patients) completed December 2021. Stage 3 phase II (recruitment of gBRCA patients) remains open to patients in the U.K. and internationally. 5 patients have enrolled in PARTNERING. Follow-up duration is 10 years. Clinical trial information: NCT03150576.

Abstract OT2-24-01: PARTNER: Randomised, phase II/III trial to evaluate the safety and efficacy of the addition of olaparib to platinum-based neoadjuvant chemotherapy in triple negative and/or germline BRCA mutated breast cancer patients

Background: Triple Negative Breast Cancers (TNBC) are a biologically diverse and aggressive subgroup lacking targeted therapy. Germline BRCA (gBRCA) breast cancer and TNBC share some phenotypic and molecular similarities, with 10%-20% of TNBC patients having gBRCA mutations. Homologous recombination deficient tumours are particularly sensitive to PARP inhibitors such as olaparib (Lynparza). It has been shown that adjuvant olaparib for patients with high-risk, HER2-negative early breast cancer and gBRCA pathogenic or likely pathogenic variants after adjuvant or neoadjuvant chemotherapy significantly improves 3-year invasive and distant disease-free survival compared to placebo (OlympiA). Aim: To establish if the addition of olaparib to neoadjuvant platinum based chemotherapy for basal TNBC and/or gBRCA breast cancer is safe and improves efficacy (pathological complete response (pCR) rate). Trial design: 3-stage open label randomised phase II/III trial of neoadjuvant paclitaxel and carboplatin +/- olaparib, followed by clinicians' choice of anthracycline regimen. Stage 1 and 2: Randomisation (1:1:1) to either control (3 weekly carboplatin AUC5/weekly paclitaxel 80mg/m2 for 4 cycles) or one of two research arms with the same chemotherapy regimen but with two different schedules of olaparib 150mg BD for 12 days. Stage 3: Randomisation (1:1) to either control arm or to the research arm selected in stage 2. End-points: Stage 1: Safety; Stage 2: Schedule selection using pCR rate and completion rate of olaparib using a “pick-the-winner” design. Stage 3: pCR rate. This trial includes an optional pathway (PARTNERING) aiming to establish if the addition of new agents (ATR inhibitor and PDL1 inhibitor) can improve response in those patients with evidence of residual disease before surgery. Eligibility criteria: Aged 16-70; histologically confirmed invasive breast cancer; ER-negative, HER2-negative with TNBC basal phenotype or gBRCA positive, HER2-negative irrespective of hormone status; clinical stage T1-4 N0-2; performance status 0-1; treatment commenced within 6 weeks of diagnostic biopsy; biomarker scores: TILs, CK 5/6, EGFR +/- AR. Statistical methods: The recruitment of TNBC non-gBRCA and gBRCA patients is independent. Enrichment design is applied with an overall significance level 0.05(α) and 80% power. A minimum of 780 patients will be included to detect an absolute improvement of 15% (all patients and the TNBC non-gBRCA cohort) and 20% (gBRCA patients) by adding olaparib to platinum based chemotherapy. It is planned to recruit a minimum of 188 gBRCA patients. A maximum of 15 patients will be allocated into each PARTNERING cohort. Present accrual: Recruitment commenced 27 May 2016 and 678 patients from 30 sites have been accrued to date. The IDSMC reviewed the trial after Stages 1 and 2 and recommended to continue the trial without change. Data analysis for Stage 2 revealed no safety concerns and research arm 2 (olaparib on day 3 to day 14) was selected. Stage 3 Phase I recruitment is in progress (recruiting TNBC non-gBRCA and gBRCA patients) and we anticipate moving to Phase II (recruiting gBRCA patients only) by early 2022. Four patients have been accrued to the PARTNERING optional pathway to date. The trial is open and enrolling patients to UK and international sites. Contact information: partner@addenbrookes.nhs.uk

Citation Format: Lynsey M Drewett, Karen A Pinilla, Louise Grybowicz, Jerome Wulff, Alimu Dayimu, Nikolaos Demiris, Jessica Martin, Camila Maida de Pontes, Nicola Johnson, Caron Harvey, Erdem Demir, Kimberley St John Green, James Jones, Gemma Young, Anne-Laure Vallier, Wendi Qian, Andrea Machin, Karen McAdam, Rebecca Roylance, Ellen R Copson, Anne Armstrong, Nicola Levitt, Elena Provenzano, Marc Tischkowitz, Emma McMurtry, Helena Earl, Jean E Abraham. PARTNER: Randomised, phase II/III trial to evaluate the safety and efficacy of the addition of olaparib to platinum-based neoadjuvant chemotherapy in triple negative and/or germline BRCA mutated breast cancer patients [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr OT2-24-01.

Six versus 12 months' adjuvant trastuzumab in patients with HER2-positive early breast cancer: the PERSEPHONE non-inferiority RCT

BACKGROUND

The addition of adjuvant trastuzumab to chemotherapy has significantly improved outcomes for people with human epidermal growth factor receptor 2 (HER2)-positive, early, potentially curable breast cancer. Twelve months' trastuzumab, tested in registration trials, was adopted as standard adjuvant treatment in 2006. Subsequently, similar outcomes were demonstrated using 9 weeks of trastuzumab. Shorter durations were therefore tested for non-inferiority.

OBJECTIVES

To establish whether or not 6 months' adjuvant trastuzumab is non-inferior to 12 months' in the treatment of HER2-positive early breast cancer using a primary end point of 4-year disease-free survival.

DESIGN

This was a Phase III randomised controlled non-inferiority trial.

SETTING

The setting was 152 NHS hospitals.

PARTICIPANTS

A total of 4088 patients with HER2-positive early breast cancer who it was planned would receive both chemotherapy and trastuzumab took part.

INTERVENTION

Randomisation (1 : 1) to 6 months' or 12 months' trastuzumab treatment.

MAIN OUTCOMES

The primary end point was disease-free survival. The secondary end points were overall survival, cost-effectiveness and cardiac function during treatment with trastuzumab. Assuming a 4-year disease-free survival rate of 80% with 12 months' trastuzumab, 4000 patients were required to demonstrate non-inferiority of 6 months' trastuzumab (5% one-sided significance, 85% power), defining the non-inferiority limit as no worse than 3% below the standard arm. Costs and quality-adjusted life-years were estimated using a within-trial analysis and a lifetime decision-analytic model.

RESULTS

Between 4 October 2007 and 31 July 2015, 2045 patients were randomised to 12 months' trastuzumab and 2043 were randomised to 6 months' trastuzumab. Sixty-nine per cent of patients had ER-positive disease; 90% received anthracyclines (49% with taxanes; 41% without taxanes); 10% received taxanes without anthracyclines; 54% received trastuzumab sequentially after chemotherapy; and 85% received adjuvant chemotherapy (58% were node negative). At 6.1 years' median follow-up, with 389 (10%) deaths and 566 (14%) disease-free survival events, the 4-year disease-free survival rates for the 4088 patients were 89.5% (95% confidence interval 88.1% to 90.8%) in the 6-month group and 90.3% (95% confidence interval 88.9% to 91.5%) in the 12-month group (hazard ratio 1.10, 90% confidence interval 0.96 to 1.26; non-inferiority p = 0.01), demonstrating non-inferiority of 6 months' trastuzumab. Congruent results were found for overall survival (non-inferiority p = 0.0003) and landmark analyses 6 months from starting trastuzumab [non-inferiority p = 0.03 (disease-free-survival) and p = 0.006 (overall survival)]. Six months' trastuzumab resulted in fewer patients reporting adverse events of severe grade [365/1929 (19%) vs. 460/1935 (24%) for 12-month patients; p = 0.0003] or stopping early because of cardiotoxicity [61/1977 (3%) vs. 146/1941 (8%) for 12-month patients; p < 0.0001]. Health economic analysis showed that 6 months' trastuzumab resulted in significantly lower lifetime costs than and similar lifetime quality-adjusted life-years to 12 months' trastuzumab, and thus there is a high probability that 6 months' trastuzumab is cost-effective compared with 12 months' trastuzumab. Patient-reported experiences in the trial highlighted fatigue and aches and pains most frequently.

LIMITATIONS

The type of chemotherapy and timing of trastuzumab changed during the recruitment phase of the study as standard practice altered.

CONCLUSIONS

PERSEPHONE demonstrated that, in the treatment of HER2-positive early breast cancer, 6 months' adjuvant trastuzumab is non-inferior to 12 months'. Six months' treatment resulted in significantly less cardiac toxicity and fewer severe adverse events.

FUTURE WORK

Ongoing translational work investigates patient and tumour genetic determinants of toxicity, and trastuzumab efficacy. An individual patient data meta-analysis with PHARE and other trastuzumab duration trials is planned.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN52968807, EudraCT 2006-007018-39 and ClinicalTrials.gov NCT00712140.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 40. See the NIHR Journals Library website for further project information.

Abstract P3-10-05: Preliminary safety data from stage 1 and 2 of the phase II/III PARTNER trial: Addition of olaparib to platinum-based neoadjuvant chemotherapy in triple negative and/or germline BRCA mutated breast cancer patients

Background: Triple negative breast cancers (TNBCs) are an aggressive and diverse subgroup with no specific targeted therapies currently available. Basal TNBCs show some phenotypic and molecular similarities with germline BRCA mutated BC (gBRCA). In gBRCA patients, and potentially other homologous recombination deficiencies, these already compromised pathways may allow PARP inhibitors (olaparib) to work more effectively. PARTNER was designed to establish if the addition of olaparib to neoadjuvant platinum-based chemotherapy for gBRCA and/or basal TNBC is safe and improves efficacy (pathological complete response (pCR)). This is the first time a clinical trial provides safety data of the combination of olaparib with platinum and taxane chemotherapy in an early breast cancer setting. Methods: PARTNER is a 3-stage open label randomised Phase II/III trial of neoadjuvant Carboplatin AUC5 with weekly Paclitaxel 80mg/m2 (CP) +/- olaparib (O) 150mgBD for 12 days x 4 cycles, followed by clinicians' choice of anthracycline regimen x 3 cycles. Basal-TNBC and/or gBRCA patients are eligible for inclusion. Primary endpoints are defined by stage: Stage 1 - Safety, Stage2 - Schedule selection, and Stage 3 - Efficacy (pCR rate). The trial is now powered for efficacy analysis in the BRCA and non-BRCA population independently. Stage 1 and 2 randomization was(1:1:1) to CP: CP + O from day (D) -2: or CP + O from D 3. G-CSF was mandatory during the first 4 cycles of treatment. We present a pooled-safety analysis from Stage 1 and 2 of the two research arms only. Recruitment continues into Stage 3. Results: Between June 2016 and April 2018, 159 patients were recruited among the three arms. Overall, median age was 48.2 [range 22.3- 70.9]; 12% had Tumours &gt;5cm, 34% had Axillary involvement; 17% were gBRCA. Adverse events (AE) that were reported as common (in at least 10% of patients) were Anaemia 23%, Neutropenia 18% and Infection 10%. Fatigue and Diarrhoea were next most prevalent with 9% and 6% respectively. The most common AE Grade &gt;=3 were haematological events. These include Neutropenia 19%, Anaemia 15%, and Thrombocytopenia 5%. Febrile Neutropenia and Haemorrhage were reported in only 2% and 1% of cases. Grade 3 Non- haematological events were Fatigue 7%, Hypertension 3%, Headache 3% and Diarrhoea 2%. Grade 3 Sensory neuropathy was present in 2% of patients. No grade 4 sensory or motor neuropathy events were described. Serious adverse reactions related to investigational regimen were reported in 17% of patients and include fever and infection with 8 and 4 events respectively. No toxicity related deaths were reported. As per July 8th 2019, 373 patients have been recruited from which 58 were gBRCA. Conclusions: Combinations of olaparib with neoadjuvant CP chemotherapy showed an acceptable and manageable toxicity profile. Although haematological events were the most common, they did not exceed historical frequencies reported for standard chemotherapy regimens. Final safety analysis will be performed once recruitment is complete and will include detailed long-term neuropathy data.

Citation Format: Karen Pinilla Alba, Emma McMurtry, Anne-Laure Vallier, Louise Grybowicz, Ellen Copson, Anne Armstrong, Rebecca Roylance, Wendi Qian, Nikolaos Demiris, Stanly Thomas, Caron Harvey, Luke Hughes-Davies, Karen McAdam, Paula del Rosario, Bryony Harrop, Elena Provenzano, Marc Tischkowitz, Helena M Earl, Jean E Abraham. Preliminary safety data from stage 1 and 2 of the phase II/III PARTNER trial: Addition of olaparib to platinum-based neoadjuvant chemotherapy in triple negative and/or germline BRCA mutated breast cancer patients [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-10-05.

POSEIDON Trial Phase 1b Results: Safety, Efficacy and Circulating Tumor DNA Response of the Beta Isoform-Sparing PI3K Inhibitor Taselisib (GDC-0032) Combined with Tamoxifen in Hormone Receptor Positive Metastatic Breast Cancer Patients

PURPOSE

The strategy of combining endocrine therapy with PI3K-mTOR inhibition has shown promise in estrogen receptor (ER)-positive breast cancer, but new agents and combinations with a better therapeutic index are urgently needed. Taselisib is a potent, selective, beta-isoform-sparing PI3 kinase inhibitor.

PATIENTS AND METHODS

30 patients with ER-positive, metastatic breast cancer who had failed prior endocrine therapy were treated with escalating doses of taselisib (2 or 4 mg in an intermittent or continuous schedule) combined with tamoxifen 20 mg once daily in this phase 1b study using a "rolling six" design.

RESULTS

Taselisib combined with tamoxifen was generally well tolerated, with treatment-emergent adverse events as expected for this class of drugs, including diarrhea (13 patients, 43%), mucositis (10 patients, 33%), and hyperglycemia (8 patients, 27%). No dose-limiting toxicities were observed. Objective responses were seen in 6 of 25 patients with RECIST-measurable disease (ORR 24%). Median time to disease progression was 3.7 months. Twelve of 30 patients (40%) had disease control for 6 months or more. Circulating tumor (ct)DNA studies using next-generation tagged amplicon sequencing identified early indications of treatment response and mechanistically relevant correlates of clinical drug resistance (e.g., mutations in KRAS, ERBB2) in some patients.

CONCLUSIONS

Taselisib can be safely combined with tamoxifen at the recommended phase 2 dose of 4 mg given once daily on a continuous schedule. Preliminary evidence of antitumor activity was seen in both PIK3CA mutant and wild-type cancers. The randomized phase 2 part of POSEIDON (testing tamoxifen plus taselisib or placebo) is currently recruiting.

6 versus 12 months of adjuvant trastuzumab for HER2-positive early breast cancer (PERSEPHONE): 4-year disease-free survival results of a randomised phase 3 non-inferiority trial

BACKGROUND

Adjuvant trastuzumab significantly improves outcomes for patients with HER2-positive early breast cancer. The standard treatment duration is 12 months but shorter treatment could provide similar efficacy while reducing toxicities and cost. We aimed to investigate whether 6-month adjuvant trastuzumab treatment is non-inferior to the standard 12-month treatment regarding disease-free survival.

METHODS

This study is an open-label, randomised phase 3 non-inferiority trial. Patients were recruited from 152 centres in the UK. We randomly assigned patients with HER2-positive early breast cancer, aged 18 years or older, and with a clear indication for chemotherapy, by a computerised minimisation process (1:1), to receive either 6-month or 12-month trastuzumab delivered every 3 weeks intravenously (loading dose of 8 mg/kg followed by maintenance doses of 6 mg/kg) or subcutaneously (600 mg), given in combination with chemotherapy (concurrently or sequentially). The primary endpoint was disease-free survival, analysed by intention to treat, with a non-inferiority margin of 3% for 4-year disease-free survival. Safety was analysed in all patients who received trastuzumab. This trial is registered with EudraCT (number 2006-007018-39), ISRCTN (number 52968807), and ClinicalTrials.gov (number NCT00712140).

FINDINGS

Between Oct 4, 2007, and July 31, 2015, 2045 patients were assigned to 12-month trastuzumab treatment and 2044 to 6-month treatment (one patient was excluded because they were double randomised). Median follow-up was 5·4 years (IQR 3·6-6·7) for both treatment groups, during which a disease-free survival event occurred in 265 (13%) of 2043 patients in the 6-month group and 247 (12%) of 2045 patients in the 12-month group. 4-year disease-free survival was 89·4% (95% CI 87·9-90·7) in the 6-month group and 89·8% (88·3-91·1) in the 12-month group (hazard ratio 1·07 [90% CI 0·93-1·24], non-inferiority p=0·011), showing non-inferiority of the 6-month treatment. 6-month trastuzumab treatment resulted in fewer patients reporting severe adverse events (373 [19%] of 1939 patients vs 459 [24%] of 1894 patients, p=0·0002) or stopping early because of cardiotoxicity (61 [3%] of 1939 patients vs 146 [8%] of 1894 patients, p<0·0001).

INTERPRETATION

We have shown that 6-month trastuzumab treatment is non-inferior to 12-month treatment in patients with HER2-positive early breast cancer, with less cardiotoxicity and fewer severe adverse events. These results support consideration of reduced duration trastuzumab for women at similar risk of recurrence as to those included in the trial.

FUNDING

UK National Institute for Health Research, Health Technology Assessment Programme.

Adjuvant trastuzumab duration trials in HER2 positive breast cancer - what results would be practice-changing? Persephone investigator questionnaire prior to primary endpoint results

BACKGROUND

Twelve months treatment is the current standard of care for adjuvant trastuzumab in patients with HER2 positive early breast cancer however the optimal duration is not known. Persephone is a non-inferiority randomised controlled trial comparing 6- to 12-months of trastuzumab. In this trial there will be a trade-off between a possible small decrease in disease-free survival (DFS) with 6-months and reduced cardiotoxicity and cost.

METHODS

A structured questionnaire asked clinicians who had recruited patients into the Persephone trial about their prior beliefs with regards to the clinical effectiveness of trastuzumab and cardiotoxicity profile, in the comparison of 6- and 12-month durations.

RESULTS

Fifty-one clinicians from 40 of the 152 Persephone sites completed the questionnaire. 30/50 responders (60%) believed that 6-months trastuzumab would give the same 4-year DFS rate as 12-months trastuzumab, with 21/50 (42%) holding this belief across all breast cancer subsets. In addition, 46/49 responders (94%) reported expecting to change their clinical practice to 6-months, with their prior beliefs (most commonly 85% 4-year DFS rate with 6-months) being greater than their lowest acceptable rate (most commonly 83% 4-year DFS rate with 6-months). Low levels of cardiotoxicity were expected with both 6 and 12-months trastuzumab, with the majority expecting lower levels with 6-months. With increasing hypothesised differences of cardiotoxicity rates between the two durations, significantly lower levels of 4-year DFS with 6-months trastuzumab were deemed acceptable (p < 0.0001).

CONCLUSION

Most responders believe that 6-months trastuzumab is adequate, both overall and within each subset of breast cancer, and plan to change their clinical practice if the Persephone results support their prior belief. An individual patient meta-analysis of the duration trials would give greater precision to estimates of the differences in efficacy and toxicity, and adequate statistical power to establish a 2% level of non-inferiority for 6-months adjuvant trastuzumab.

Central pathology review with two-stage quality assurance for pathological response after neoadjuvant chemotherapy in the ARTemis Trial

The ARTemis Trial tested standard neoadjuvant chemotherapy±bevacizumab in the treatment of HER2-negative early breast cancer. We compare data from central pathology review with report review and also the reporting behavior of the two central pathologists. Eight hundred women with HER2-negative early invasive breast cancer were recruited. Response to chemotherapy was assessed from local pathology reports for pathological complete response in breast and axillary lymph nodes. Sections from the original core biopsy and surgical excision were centrally reviewed by one of two trial pathologists blinded to the local pathology reports. Pathologists recorded response to chemotherapy descriptively and also calculated residual cancer burden. 10% of cases were double-reported to compare the central pathologists' reporting behavior. Full sample retrieval was obtained for 681 of the 781 patients (87%) who underwent surgery within the trial and were evaluable for pathological complete response. Four hundred and eighty-three (71%) were assessed by JSJT, and 198 (29%) were assessed by EP. Residual cancer burden calculations were possible in 587/681 (86%) of the centrally reviewed patients, as 94/681 (14%) had positive sentinel nodes removed before neoadjuvant chemotherapy invalidating residual cancer burden scoring. Good concordance was found between the two pathologists for residual cancer burden classes within the 65-patient quality assurance exercise (kappa 0.63 (95% CI: 0.57-0.69)). Similar results were obtained for the between-treatment arm comparison both from the report review and the central pathology review. For pathological complete response, report review was as good as central pathology review but for minimal residual disease, report review overestimated the extent of residual disease. In the ARTemis Trial central pathology review added little in the determination of pathological complete response but had a role in evaluating low levels of residual disease. Calculation of residual cancer burden was a simple and reproducible method of quantifying response to neoadjuvant chemotherapy as demonstrated by performance comparison of the two pathologists.

PARTNER: Randomised, phase II/III trial to evaluate the safety and efficacy of the addition of olaparib to platinum-based neoadjuvant chemotherapy in triple negative and/or germline BRCA mutated breast cancer patients

TPS591

Background: No specific targeted therapies are available for Triple Negative Breast Cancers (TNBC), an aggressive and diverse subgroup. The basal TNBC sub-group show some phenotypic and molecular similarities with germline BRCA (gBRCA). In gBRCA patients, and potentially other homologous recombination deficiencies, these already compromised pathways may allow drugs called PARP inhibitors (olaparib) to work more effectively. Aims: To establish if the addition of olaparib to neoadjuvant platinum based chemotherapy for basal TNBC and/or gBRCA breast cancer is safe and improves efficacy (pathological complete response (pCR)). Trial design: 3-stage open label randomised phase II/III trial of neoadjuvant paclitaxel and carboplatin +/- olaparib, followed by clinicians' choice of anthracycline regimen. Stage 1 and 2: Patients are randomised (1:1:1) to either control (3 weekly carboplatin AUC5/weekly paclitaxel 80mg/m2 for 4 cycles) or one of two research arms with the same chemotherapy regimen but with two different schedules of olaparib 150mg BD for 12 days. Stage 3: Patients are randomised (1:1) to either control arm or to the research arm selected in stage 2. Methods: Stage 1 - Safety: both research arms combined. Stage 2 - Schedule selection criteria: pCR rate and completion rate of olaparib protocol treatment. It is a “pick-the-winner” design with 53 patients in each research arm. This allows a 90% power, 5% one-sided significance level to test null hypothesis of pCR ≤35% versus an alternative hypothesis of pCR ≥55% in each of the research arms. Stage 3 - Efficacy: anticipated pCR ~55-60% for all trial patients and ~60-65% for gBRCA patients. The trial is powered to detect an absolute improvement of 15% (all patients) and 20% (gBRCA patients) by adding olaparib to chemotherapy (enriched design). TNBC patient recruitment will be capped, to ensure required gBRCA patients are enrolled. Enrichment design is applied with overall significance level 0.05(α) = 0.025(αall)+ 0.025(αgBRCA) and 80% power. Target accrual: 527 [gBRCA 220] Current accrual: 17 Sites activated: 12 [expected number of sites 30-50].

Abstract OT2-01-11: Phase II of POSEIDON: A phase Ib / randomized phase II trial of tamoxifen plus taselisib or placebo in hormone receptor positive, HER2 negative, metastatic breast cancer patients with prior exposure to endocrine treatment

Background: The combination of PI3K-AKT-mTOR pathway inhibitors with endocrine therapy can improve clinical outcomes of hormone receptor positive (HR+) metastatic breast cancer (MBC) patients. Taselisib is a potent and selective PI3K inhibitor, with greater selectivity against mutant (MUT) PI3Kα isoforms than wild-type (WT) via a unique mechanism. Phase Ib data of POSEIDON with Taselisib + tamoxifen (TAM) demonstrated encouraging activity in patients with heavily pre-treated MBC, with an acceptable toxicity profile (Baird et al, ASCO 2016). The recommended phase II dose (RP2D) was Taselisib 4mg plus TAM 20mg, both administered on a daily continuous schedule. ctDNA monitoring may have value in drug development by (1) assessing predictive biomarkers to therapy, (2) providing an early indication of treatment response, and (3) shedding light on potential mechanisms of acquired drug resistance. In some patients included in phase Ib of POSEIDON, tumor response was preceded by a corresponding early change in plasma PIK3CA ctDNA levels. Methods: The phase II portion of the POSEIDON trial is a two-arm, randomized, double blind study of Taselisib plus TAM versus placebo (PLA) plus TAM in pre- and postmenopausal women with HR+/HER2- MBC. In the first part of the Phase II, 180 patients will be randomized (1:1) to receive continuous TAM with either Taselisib at the RP2D or PLA until disease progression, unacceptable toxicity or patient / physician decision. Crossover is allowed upon progressive disease in those patients receiving PLA plus TAM, after collection of tumor and blood samples for exploratory biomarker analysis. Stratification is based on menopausal status, histology [lobular breast cancer (LBC) vs. ductal/others], PIK3CA mutation (WT vs. exon 9 vs. exon 20), prior everolimus, timing of recurrence/progression after prior endocrine therapy, number of prior chemotherapy (CT) lines, and treatment center. After recruiting the initial 180 patients, trial will focus in LBC, until a total number of 110 patients with LBC are enrolled. Other key eligibility criteria include presence of measurable or evaluable disease (RECIST 1.1), prior progression to endocrine treatment, maximum of 5 prior CT lines in the metastatic setting, absence of diabetes under medical treatment, and absence of chronic inflammatory bowel disease. Primary endpoint is investigator-assessed PFS. Key secondary endpoints are PFS in LBC, objective response rate, clinical benefit rate, safety, and exploratory biomarker analysis (including ctDNA). The study has a 90% power at a two-sided log-rank test significance level of 0.2 to detect an HR of 0.64, which corresponds to an increase in median PFS from 4.5 months in the PLA plus TAM arm to 7 months in the Taselisib plus TAM arm. Enrollment to POSEIDON Phase II started in June 2016 (Clinicaltrials.gov NCT02285179).

Citation Format: Oliveira M, Baird RD, van Rossum AGJ, Beelen K, Garcia-Corbacho J, Mandjes IAM, Vallier AL, van Werkhoven E, Garrigós L, Kumar S, van Tinteren H, Muñoz S, Linossi C, Rosing H, Miquel JM, Schrier M, de Vries Schultink A, Saura C, Gallagher WM, Bernards R, Tabernero J, Cortés J, Caldas C, Linn SC. Phase II of POSEIDON: A phase Ib / randomized phase II trial of tamoxifen plus taselisib or placebo in hormone receptor positive, HER2 negative, metastatic breast cancer patients with prior exposure to endocrine treatment [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT2-01-11.

Trastuzumab-associated cardiac events in the Persephone trial

Background:

We report cardiac events in the Persephone trial which compares 6–12 months of adjuvant trastuzumab in women with confirmed HER2-positive, early-stage breast cancer.

Methods:

Clinical cardiac events were defined as any of the following: symptoms and/or signs of congestive heart failure (CHF) and new or altered CHF medication. In addition, left ventricular ejection fraction (LVEF) was measured at baseline and then 3 monthly for 12 months.

Results:

A total of 2500 patients, aged 22–82, were included: 1251 randomised to 12 months and 1249 to 6 months of trastuzumab treatment. A total of 93% (2335/2500) received anthracyclines, 49% of these (1136/2335) with taxanes. Cardiotoxicity delayed treatment in 6% of 12-month and 4% of 6-month patients (P=0.01), and stopped treatment early in 8% (96/1214) of 12-month and 4% (45/1216) of 6-month patients (P<0.0001). Between 7 and 12 months, more 12-month than 6-month patients had LVEFs<50% (8% vs 5% P=0.004). LVEFs showed quadratic change over time, and 6-month patients had a more rapid recovery (P=0.02). In a landmark analysis twice as many 12-month patients, free of cardiac events at 6 months, had cardiac problems in months 7–12 (6% (66/1046) vs 3% (29/1035) of 6-month patients (P=0.0002)). Lower baseline LVEF predicted more cardiac dysfunction in both arms (reference ⩾65%: 55 to <65% OR 1.61 (95% CI 1.26–2.04); <55% OR 5.22 (3.42–7.95)) as did increasing age (reference <50: 50–59 OR 1.58 (1.17–2.12), 60–69 OR 1.91 (1.42–2.57)) 70+ OR 2.72 (1.82–4.08)) and prior use of cardiac medication (OR 8.46 (4.69–15.25)). >3 cycles of anthracycline was associated with higher risk of cardiac events only for 12-month patients (OR 1.41 (1.04–1.90)), and not for 6-month patients (OR 1.28 (0.91–1.79)).

Conclusions:

We demonstrate significantly fewer cardiac events from 6 months of adjuvant trastuzumab compared with that from 12 months. This cardiac signal adds importance to the question of the optimum duration of adjuvant trastuzumab treatment. If 6 months is proven to have non-inferior outcomes to 12 months treatment, these data would support 6 months as the standard of care.

The Relationship between Common Genetic Markers of Breast Cancer Risk and Chemotherapy-Induced Toxicity: A Case-Control Study

Ninety-four common genetic variants are confirmed to be associated with breast cancer. This study tested the hypothesis that breast cancer susceptibility variants may also be associated with chemotherapy-induced toxicity through shared mechanistic pathways such as DNA damage response, an association that, to our knowledge, has not been previously investigated. The study included breast cancer patients who received neoadjuvant/adjuvant chemotherapy from the Pharmacogenetic SNPs (PGSNPS) study. For each patient, a breast cancer polygenic risk score was created from the 94 breast cancer risk variants, all of which were genotyped or successfully imputed in PGSNPS. Logistic regression was performed to test the association with two clinically important toxicities: taxane- related neuropathy (n = 1279) and chemotherapy-induced neutropenia (n = 1676). This study was well powered (≥96%) to detect associations between polygenic risk score and chemotherapy toxicity. Patients with high breast cancer risk scores experienced less neutropenia compared to those with low risk scores (adjusted p-value = 0.06). Exploratory functional pathway analysis was performed and no functional pathways driving this trend were identified. Polygenic risk was not associated with taxane neuropathy (adjusted p-value = 0.48). These results suggest that breast cancer patients with high genetic risk of breast cancer, conferred by common variants, can safely receive standard chemotherapy without increased risk of taxane-related sensory neuropathy or chemotherapy-induced neutropenia and may experience less neutropenia. As neutropenia has previously been associated with improved survival and may reflect drug efficacy, these patients may be less likely to benefit from standard chemotherapy treatment.

Computational pathology of pre-treatment biopsies identifies lymphocyte density as a predictor of response to neoadjuvant chemotherapy in breast cancer

BACKGROUND

There is a need to improve prediction of response to chemotherapy in breast cancer in order to improve clinical management and this may be achieved by harnessing computational metrics of tissue pathology. We investigated the association between quantitative image metrics derived from computational analysis of digital pathology slides and response to chemotherapy in women with breast cancer who received neoadjuvant chemotherapy.

METHODS

We digitised tissue sections of both diagnostic and surgical samples of breast tumours from 768 patients enrolled in the Neo-tAnGo randomized controlled trial. We subjected digital images to systematic analysis optimised for detection of single cells. Machine-learning methods were used to classify cells as cancer, stromal or lymphocyte and we computed estimates of absolute numbers, relative fractions and cell densities using these data. Pathological complete response (pCR), a histological indicator of chemotherapy response, was the primary endpoint. Fifteen image metrics were tested for their association with pCR using univariate and multivariate logistic regression.

RESULTS

Median lymphocyte density proved most strongly associated with pCR on univariate analysis (OR 4.46, 95 % CI 2.34-8.50, p < 0.0001; observations = 614) and on multivariate analysis (OR 2.42, 95 % CI 1.08-5.40, p = 0.03; observations = 406) after adjustment for clinical factors. Further exploratory analyses revealed that in approximately one quarter of cases there was an increase in lymphocyte density in the tumour removed at surgery compared to diagnostic biopsies. A reduction in lymphocyte density at surgery was strongly associated with pCR (OR 0.28, 95 % CI 0.17-0.47, p < 0.0001; observations = 553).

CONCLUSIONS

A data-driven analysis of computational pathology reveals lymphocyte density as an independent predictor of pCR. Paradoxically an increase in lymphocyte density, following exposure to chemotherapy, is associated with a lack of pCR. Computational pathology can provide objective, quantitative and reproducible tissue metrics and represents a viable means of outcome prediction in breast cancer.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00070278 ; 03/10/2003.

A nested cohort study of 6,248 early breast cancer patients treated in neoadjuvant and adjuvant chemotherapy trials investigating the prognostic value of chemotherapy-related toxicities

BACKGROUND

The relationship between chemotherapy-related toxicities and prognosis is unclear. Previous studies have examined the association of myelosuppression parameters or neuropathy with survival and reported conflicting results. This study aims to investigate 13 common chemotherapy toxicities and their association with relapse-free survival and breast cancer-specific survival.

METHODS

Chemotherapy-related toxicities were collected prospectively for 6,248 women with early-stage breast cancer from four randomised controlled trials (NEAT; BR9601; tAnGo; Neo-tAnGo). Cox proportional-hazards modelling was used to analyse the association between chemotherapy-related toxicities and both breast cancer-specific survival and relapse-free survival. Models included important prognostic factors and stratified by variables violating the proportional hazards assumption.

RESULTS

Multivariable analysis identified severe neutropenia (grades ≥3) as an independent predictor of relapse-free survival (hazard ratio (HR) = 0.86; 95% confidence interval (CI), 0.76-0.97; P = 0.02). A similar trend was seen for breast cancer-specific survival (HR = 0.87; 95% CI, 0.75-1.01; P = 0.06). Normal/low BMI patients experienced more severe neutropenia (P = 0.008) than patients with higher BMI. Patients with fatigue (grades ≥3) showed a trend towards reduced survival (breast cancer-specific survival: HR = 1.17; 95% CI, 0.99-1.37; P = 0.06). In the NEAT/BR9601 sub-group analysis by treatment component, this effect was statistically significant (HR = 1.61; 95% CI, 1.13-2.30; P = 0.009).

CONCLUSIONS

This large study shows a significant association between chemotherapy-induced neutropenia and increased survival. It also identifies a strong relationship between low/normal BMI and increased incidence of severe neutropenia. It provides evidence to support the development of neutropenia-adapted clinical trials to investigate optimal dose calculation and its impact on clinical outcome. This is important in populations where obesity may lead to sub-optimal chemotherapy doses.

Neoadjuvant trials in early breast cancer: pathological response at surgery and correlation to longer term outcomes - what does it all mean?

BACKGROUND

Neoadjuvant breast cancer trials are important for speeding up the introduction of new treatments for patients with early breast cancer and for the highly productive translational research which they facilitate. Meta-analysis of trial data shows clear correlation between pathological response at surgery after neoadjuvant chemotherapy and longer-term outcomes at an individual patient level. However, this does not appear to be present on individual trial level analysis, when correlating improved outcome for the investigational arm for the primary endpoint (pathological response) with longer-term outcomes.

DISCUSSION

The correlation between pathological response and longer-term outcomes in trials is dependent on many factors. These include definitions of pathological response, both complete and partial; assessment methods for pathological response at surgery; subtype and prognosis of breast cancer at diagnosis; number of patients recruited; adjuvant treatments; the mechanism of action of the investigational drug; the length of follow-up at the time of reporting; the definitions used in longer-term outcomes analysis; clonal heterogeneity; and new adaptive trial designs with additional neo/adjuvant treatments. Future developments of neoadjuvant breast cancer trials are discussed. With so many factors influencing the correlation of longer-term outcomes for trial-level data, we conclude that the main focus of neoadjuvant trials should remain the primary endpoint of pathological response. Neoadjuvant breast cancer trials are very important investigational studies that will continue to increase our understanding of the disease and offer the potential of more rapid introduction of new treatments for women with high-risk early breast cancer. In the future, we are likely to see both novel trial designs adopted in the neoadjuvant context and modifications of neo/adjuvant treatments for pathological non-responders within clinical trials. Both of these have the intention of improving longer-term outcomes for patients who do not have a good pathological response to first-line neoadjuvant treatment. If successful, these developments are likely to reduce further any positive correlation between pathological response and longer-term outcomes.

A Bayesian adaptive design for biomarker trials with linked treatments

BACKGROUND

Response to treatments is highly heterogeneous in cancer. Increased availability of biomarkers and targeted treatments has led to the need for trial designs that efficiently test new treatments in biomarker-stratified patient subgroups.

METHODS

We propose a novel Bayesian adaptive randomisation (BAR) design for use in multi-arm phase II trials where biomarkers exist that are potentially predictive of a linked treatment's effect. The design is motivated in part by two phase II trials that are currently in development. The design starts by randomising patients to the control treatment or to experimental treatments that the biomarker profile suggests should be active. At interim analyses, data from treated patients are used to update the allocation probabilities. If the linked treatments are effective, the allocation remains high; if ineffective, the allocation changes over the course of the trial to unlinked treatments that are more effective.

RESULTS

Our proposed design has high power to detect treatment effects if the pairings of treatment with biomarker are correct, but also performs well when alternative pairings are true. The design is consistently more powerful than parallel-groups stratified trials.

CONCLUSIONS

This BAR design is a powerful approach to use when there are pairings of biomarkers with treatments available for testing simultaneously.

Efficacy of neoadjuvant bevacizumab added to docetaxel followed by fluorouracil, epirubicin, and cyclophosphamide, for women with HER2-negative early breast cancer (ARTemis): an open-label, randomised, phase 3 trial

BACKGROUND

The ARTemis trial was developed to assess the efficacy and safety of adding bevacizumab to standard neoadjuvant chemotherapy in HER2-negative early breast cancer.

METHODS

In this randomised, open-label, phase 3 trial, we enrolled women (≥18 years) with newly diagnosed HER2-negative early invasive breast cancer (radiological tumour size >20 mm, with or without axillary involvement), at 66 centres in the UK. Patients were randomly assigned via a central computerised minimisation procedure to three cycles of docetaxel (100 mg/m(2) once every 21 days) followed by three cycles of fluorouracil (500 mg/m(2)), epirubicin (100 mg/m(2)), and cyclophosphamide (500 mg/m(2)) once every 21 days (D-FEC), without or with four cycles of bevacizumab (15 mg/kg) (Bev+D-FEC). The primary endpoint was pathological complete response, defined as the absence of invasive disease in the breast and axillary lymph nodes, analysed by intention to treat. The trial has completed and follow-up is ongoing. This trial is registered with EudraCT (2008-002322-11), ISRCTN (68502941), and ClinicalTrials.gov (NCT01093235).

FINDINGS

Between May 7, 2009, and Jan 9, 2013, we randomly allocated 800 participants to D-FEC (n=401) and Bev+D-FEC (n=399). 781 patients were available for the primary endpoint analysis. Significantly more patients in the bevacizumab group achieved a pathological complete response compared with those treated with chemotherapy alone: 87 (22%, 95% CI 18-27) of 388 patients in the Bev+D-FEC group compared with 66 (17%, 13-21) of 393 patients in the D-FEC group (p=0·03). Grade 3 and 4 toxicities were reported at expected levels in both groups, although more patients had grade 4 neutropenia in the Bev+D-FEC group than in the D-FEC group (85 [22%] vs 68 [17%]).

INTERPRETATION

Addition of four cycles of bevacizumab to D-FEC in HER2-negative early breast cancer significantly improved pathological complete response. However, whether the improvement in pathological complete response will lead to improved disease-free and overall survival outcomes is unknown and will be reported after longer follow-up. Meta-analysis of available neoadjuvant trials is likely to be the only way to define subgroups of early breast cancer that would have clinically significant long-term benefit from bevacizumab treatment.

FUNDING

Cancer Research UK, Roche, Sanofi-Aventis.

Abstract PD2-3: ARTemis: A randomised trial of bevacizumab with neo-adjuvant chemotherapy for patients with HER2-negative early breast cancer

Background: Bevacizumab (bev) has been used with neo-adjuvant chemotherapy (NACT) in breast cancer trials. Geparquinto reported benefit for bev in triple negative (neg) patients (pts) (pathological complete response (pCR) 36.4% vs 27.8% p=0.02), as did CALGB 40603 (pCR 52% vs 44%, p=0.057), although NSABP-B40 showed benefit in ER positive (pos) pts (pCR 23.3% vs 15.2%, p=0.008).

Methods: ARTemis is a randomised phase 3 trial adding bev to NACT (docetaxel (D)-FEC). Pts with HER2-neg invasive breast cancer were eligible. Stratification was by age, ER status (neg:weak pos:strong pos), tumour size (T2:T3/4), clinical involvement of axillary nodes and inflammatory/locally advanced disease. Pts were randomised (1:1) to bev+D-FEC or D-FEC. The primary endpoint was pCR, defined as no residual invasive cancer in the breast or axillary lymph nodes after NACT. 800 pts were required to detect 10% differences in pCR rates; 85% power, 5% alpha level.

Results: 800 pts were randomised from 66 UK centres (May 2009 to Jan 2013). 68% were &lt;50 years old, 19% had inflammatory and/or locally advanced disease, 79% of tumours &lt;50mm, 52% clinical node pos and 33% ER-neg. A 2-reader independent review of pathology reports determined whether pCR had been achieved or, at least, minimal residual disease (MRD) status. Significantly more pts on bev+D-FEC had a pCR (22% vs 17%; adjusted p=0.03) (see table). pCR rates differed significantly across ER groups (neg 38%, weak pos 39%, strong pos 7%; p&lt;0.0001). Treatment effect of bev remained significant after adjustment for ER (p=0.03). Similarly significantly more pts on bev+D-FEC had a pCR or MRD (36% vs 29%; adjusted p=0.035). Rates differed significantly across ER groups (neg 51%, weak pos 58%, strong pos 18%; p&lt;0.0001). Treatment effect of bev remained significant after adjustment for ER (p=0.03).

  D→FECBev+D→FEC   % (95%CI)% (95%CI)p *$pCR in all breast tumours AND absence of disease in ax LNs in all breast tumours(n=66/393)(n=87/388)   17% (13-21%)22% (18-27%)0.03 ER neg (Allred 0-2) (n=253)32% (24-41)44% (36-54)  ER weak pos (Allred 3-5) (n=67)26% (13-44)52% (34-69)  ER strong pos (Allred 6-8) (n=461)7% (4-11)6% (3-10)  pCR or MRD in all breast tumours(n=114/394)(n=138/388)   29% (25-34%)36% (31-41%)0.035 ER neg (Allred 0-2) (n=254)45% (36-54)56% (47-65)  ER weak pos (Allred 3-5) (n=67)44% (27-62)73% (54-87)  ER strong pos (Allred 6-8) (n=461)18% (13-23)19% (14-24) * Adjusted for stratification variables. $ Primary endpoint for the ARTemis trial

Conclusions: ARTemis showed a significant improvement in both pCR and MRD rates with the addition of bev to D-FEC. ER-neg and ER-weak pos / HER2-neg breast cancer pts appeared to benefit most from bev, whilst pCR and MRD rates in ER-strong pos pts were lower and did not appear to benefit from bev. Our results are similar to those reported in Geparquinto and CALGB 40603.

Citation Format: Helena M Earl, Louise Hiller, Janet A Dunn, Clare Blenkinsop, Louise Grybowicz, Anne-Laure Vallier, Jean Abraham, Jeremy Thomas, Elena Provenzano, Luke Hughes-Davies, Karen McAdam, Stephen Chan, Rizvana Ahmad, Tamas Hickish, Stephen Houston, Daniel Rea, John Bartlett, Carlos Caldas, David Cameron, Larry Hayward. ARTemis: A randomised trial of bevacizumab with neo-adjuvant chemotherapy for patients with HER2-negative 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 PD2-3.

Replication of genetic polymorphisms reported to be associated with taxane-related sensory neuropathy in patients with early breast cancer treated with Paclitaxel

PURPOSE

Associations between taxane-related sensory neuropathy (TRSN) and single-nucleotide polymorphisms (SNP) have previously been reported, but few have been replicated in large, independent validation studies. This study evaluates the association between previously investigated SNPs and TRSN, using genotype data from a study of chemotherapy-related toxicity in patients with breast cancer.

EXPERIMENTAL DESIGN

We investigated 73 SNPs in 50 genes for their contribution to TRSN risk, using genotype data from 1,303 European patients. TRSN was assessed using National Cancer Institute common toxicity criteria for adverse events classification. Unconditional logistic regression evaluated the association between each SNP and TRSN risk (primary analysis). Cox regression analysis assessed the association between each SNP and cumulative taxane dose causing the first reported moderate/severe TRSN (secondary analysis). The admixture likelihood (AML) test, which considers all SNPs with a prior probability of association with TRSN together, tested the hypothesis that certain SNPs are truly associated.

RESULTS

The AML test provided strong evidence for the association of some SNPs with TRSN (P = 0.023). The two most significantly associated SNPs were rs3213619(ABCB1) [OR = 0.47; 95% confidence interval (CI), 0.28-0.79; P = 0.004] and rs9501929(TUBB2A) (OR = 1.80; 95% CI, 1.20-2.72; P = 0.005). A further 9 SNPs were significant at P-value ≤ 0.05.

CONCLUSION

This is currently the largest study investigating SNPs associated with TRSN. We found strong evidence that SNPs within genes in taxane pharmacokinetic and pharmacodynamic pathways contribute to TRSN risk. However, a large proportion of the inter-individual variability in TRSN remains unexplained. Further validated results from GWAS will help to identify new pathways, genes, and SNPs involved in TRSN susceptibility.

Effects of the addition of gemcitabine, and paclitaxel-first sequencing, in neoadjuvant sequential epirubicin, cyclophosphamide, and paclitaxel for women with high-risk early breast cancer (Neo-tAnGo): an open-label, 2×2 factorial randomised phase 3 trial

BACKGROUND

Anthracyclines and taxanes have been the standard neoadjuvant chemotherapies for breast cancer in the past decade. We aimed to assess safety and efficacy of the addition of gemcitabine to accelerated paclitaxel with epirubicin and cyclophosphamide, and also the effect of sequencing the blocks of epirubicin and cyclophosphamide and paclitaxel (with or without gemcitabine).

METHODS

In our randomised, open-label, 2×2 factorial phase 3 trial (Neo-tAnGo), we enrolled women (aged >18 years) with newly diagnosed breast cancer (tumour size >20 mm) at 57 centres in the UK. Patients were randomly assigned via a central randomisation procedure to epirubicin and cyclophosphamide then paclitaxel (with or without gemcitabine) or paclitaxel (with or without gemcitabine) then epirubicin and cyclophosphamide. Four cycles of each component were given. The primary endpoint was pathological complete response (pCR), defined as absence of invasive cancer in the breast and axillary lymph nodes. This study is registered with EudraCT (2004-002356-34), ISRCTN (78234870), and ClinicalTrials.gov (NCT00070278).

FINDINGS

Between Jan 18, 2005, and Sept 28, 2007, we randomly allocated 831 participants; 207 received epirubicin and cyclophosphamide then paclitaxel; 208 were given paclitaxel then epirubicin and cyclophosphamide; 208 had epirubicin and cyclophosphamide followed by paclitaxel and gemcitabine; and 208 received paclitaxel and gemcitabine then epirubicin and cyclophosphamide. 828 patients were eligible for analysis. Median follow-up was 47 months (IQR 37-51). 207 (25%) patients had inflammatory or locally advanced disease, 169 (20%) patients had tumours larger than 50 mm, 413 (50%) patients had clinical involvement of axillary nodes, 276 (33%) patients had oestrogen receptor (ER)-negative disease, and 191 (27%) patients had HER2-positive disease. Addition of gemcitabine did not increase pCR: 70 (17%, 95% CI 14-21) of 404 patients in the epirubicin and cyclophosphamide then paclitaxel group achieved pCR compared with 71 (17%, 14-21) of 408 patients who received additional gemcitabine (p=0·98). Receipt of a taxane before anthracycline was associated with improved pCR: 82 (20%, 95% CI 16-24) of 406 patients who received paclitaxel with or without gemcitabine followed by epirubicin and cyclophosphamide achieved pCR compared with 59 (15%, 11-18) of 406 patients who received epirubicin and cyclophosphamide first (p=0·03). Grade 3 toxicities were reported at expected levels: 173 (21%) of 812 patients who received treatment and had full treatment details had grade 3 neutropenia, 66 (8%) had infection, 41 (5%) had fatigue, 41 (5%) had muscle and joint pains, 37 (5%) had nausea, 36 (4%) had vomiting, 34 (4%) had neuropathy, 23 (3%) had transaminitis, 16 (2%) had acute hypersensitivity, and 20 (2%) had a rash. 86 (11%) patients had grade 4 neutropenia and 3 (<1%) had grade 4 infection.

INTERPRETATION

Although addition of gemcitabine to paclitaxel and epirubicin and cyclophosphamide chemotherapy does not improve pCR, sequencing chemotherapy so that taxanes are received before anthracyclines could improve pCR in standard neoadjuvant chemotherapy for breast cancer.

FUNDING

Cancer Research UK, Eli Lilly, Bristol-Myers Squibb.

Sentinel lymph node biopsy (SLNB) prior to primary chemotherapy (PC) in breast cancer patients

Abstract #5111

Background: Lymph node status is the single most important determinant of prognosis and is used for planning adjuvant therapy. Patient selection and timing of SLNB for PC continue to evolve; SLNB prior to PC may allow more accurate initial staging and prognostication and guide decisions about adjuvant treatment.&#x2028; Methods: 78 patients (pts) who were treated in the Cambridge Breast Unit as part of Neo-tAnGo (a multicentre PC trial). 57 were identified as potentially suitable for SLNB pre-PC (clinically node negative, non-inflammatory tumours 2–5cm in size). 38 had axillary ultrasound, and of these, 18 had sonographically suspicious nodes. 12/18 had confirmed nodal metastasis on core biopsy (CB) and had direct ALND post-PC. The remaining 20 patients had innocent nodes or were CB negative, of whom 19 underwent SLNB. A total of 19 patients in this subgroup did not undergo axillary ultrasound; 16 of these proceeded to ALND post-PC and 3 to SLN biopsy pre-PC according to unit policy at the time. A total of 22 (19 + 3) pts were available for analysis of SLN biopsy pre-PC in terms of time to treatment compared to the remainder of the centre's cohort in the Neo-tAnGo study. 42, (22 SLNB + 20 node positive on CB), were analysed as having axillary pathological staging before PC and compared to the other patient cohort on study.&#x2028; Results: The SLN was successfully identified in all 22 pts using dual localisation techniques with a mean SLN harvest of 2.8 nodes per patient (range 1–10). 6/22 pts (27%) were node positive, and 5 had single SLN involvement (4 macro-; 1 micro-) and one had a macro- and a micrometastasis in 2 different nodes. The mean time from diagnosis to start of PC in the SLN group was 23 days (range 8–43) compared 18 days (range 7–36) for the comparator cohort on study (p=0.02). When all 42 pts with pathological axillary assessment were analysed (including clinically node positive pts with tumours &gt;5cm), there was no significant difference in time from diagnosis to start of PC for pts undergoing CB and/or SLNB (21 days) compared with no axillary assessment (17 days) (wilcoxon test p=0.10). The mean number of nodes removed on completion ALND was 9 (range 4–16). There was no evidence of any viable tumour or fibrosis in any of the non-SLN's (NSLN) examined. Amongst the group of 18 ultrasound/CB positive pts who underwent ALND without SLNB, nodal disease was found in 9 (50%) with evidence of pathological downstaging in 4 (22%).&#x2028; Conclusion: There is potential loss of staging information when SLNB is performed after PC and the clinical significance of a negative SLNB result in this setting is uncertain. A combination of axillary ultrasound (with CB) and SLNB can more accurately stage the axilla without significant overall delays in commencement of PC for clinically node positive and negative pts. Downstaging of disease in NLSN may occur in response to PC with a lower NSLN rate (0%) when compared to primary surgical treatment in smaller tumours (15–25%).

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5111.