De novo metastatic breast cancer in patients with a small locoregional tumour (T1-T2/N0): Characteristics and prognosis

INTRODUCTION

The estimated rate of de novo metastatic breast cancer (dnMBC) at the time of diagnosis is between 5 to 12%. International guidelines recommend metastatic work-up (MWU) only in women with advanced breast cancer. The purpose of this study was to describe the characteristics and prognosis of patients with dnMBC diagnosed without an initial indication for MWU.

METHODS

We conducted a retrospective, comparative study in dnMBC patients selected from the ESME-MBC cohort. Patients were treated in France between 2008 and 2016. We compared two populations: patients in whom dnMBC was diagnosed by staging although not indicated by guidelines (non-guideline staging [NGS]) and those in whom dnMBC was diagnosed by guideline staging (GS).

RESULTS

During the study period, 22,463 patients with MBC were included in the ESME cohort. Among them, 6698 were dnMBC patients. In 247 of these patients (6% of dnMBC and 1% of the overall population), dnMBC was diagnosed by non-guideline staging. Women in this group were significantly younger (57 vs. 59 years, p = 0.02) and had fewer metastatic sites at diagnosis than dnMBC-GS patients. The two groups were not significantly different in terms of the other characteristics. Overall survival (OS) and progression-free survival (PFS) were better in the dnMBC-NGS group than in the dnMBC-GS group. The impact on survival was confirmed by univariate and multivariate analysis (HR 1.83 [1.31-2.57], p < 0.01).

CONCLUSION

This study provides the first description of a very specific population. These patients with dnMBC-NGS were younger and more likely to have oligometastatic disease with a better prognosis.

Abstract GS3-07: Clinical utility of circulating tumor cell count as a tool to chose between first line hormone therapy and chemotherapy for ER+ HER2- metastatic breast cancer: Results of the phase III STIC CTC trial

Background: In ER+ HER2- metastatic breast cancer (MBC) patients, the clinical choice between 1st line hormone therapy (HT, the recommended option) or chemotherapy (CT) is based on the absence of “visceral crisis” or adverse prognostic factors, with no proven/objective criteria. In that context, STIC CTC (NCT01710605) was set up as a strategy trial to test whether circulating tumor cells (CTC) count could help customize the choice between 1st line HT or CT.

Methods: For this multicenter phase 3 non-inferiority trial, the main inclusion criteria were: ER+ HER2- MBC with no prior therapy, PS≤2, no contra-indication to HT or CT and informed consent. The a priori treatment choice (HT or CT) and CTC count (CellSearch®) were obtained in all patients prior to randomization. Patients were randomized 1:1 between clinically-driven choice (CTC count not disclosed, HT or CT administered as decided a priori), or a CTC-driven choice (HT if &lt;5 CTC/7.5ml, CT if ≥5 CTC/7.5ml). The primary objective was treatment efficacy (PFS hazard ratio), non-inferiority being established if the upper bound of the PFS HR 2-sided 90%CI is ≤1.25; secondary objectives included subgroup analyses (CTC status, patient characteristics) and OS.

Results: 761 MBC patients were randomized between 02/2012 and 08/2016. Baseline characteristics: 7.8% of patients had a PS=2, 24.1% had a de novo metastatic disease; 63.3% received prior adjuvant HT and 49.9% prior adjuvant CT; 31.3% had ≥3 metastatic sites. A priori treatments (HT or CT) and CTC count (&lt; or ≥5 CTC/7.5ml) were well balanced between the two arms. After randomization, in the clinically-driven arm, N=267 (72.4%) patients received HT and N=102 (27.6%) CT (as decided a priori). In the CTC-driven arm: (1) the a priori choice of HT was confirmed by a low CTC count in N=181 (67.5%) of patients, while N=87 (32.5%) were switched to CT due to a high CTC count; (2) the a priori choice of CT was confirmed by high CTC count in only N=48 (48%) patients, while N=52 (52%) were switched to HT. The primary endpoint was met, PFS being not inferior in the CTC-driven arm (HR=0.98, 90%CI=[0.84–1.13]). Analyses focusing on discordant subgroups showed that for patients with a priori choice of HT but with high CTC count (leading to a switch to CT in the CTC-arm), PFS was significantly longer in the CTC-driven arm than in the standard arm (HR=0.67, 95%CI=[0.49–0.92]; p=0.01), with a non-significant trend toward longer OS (HR=0.68, 95%CI=[0.44–1.07]; p=0.09). Inversely, for patients with a priori choice of CT but with low CTC count (i.e. de-escalation to HT in the CTC arm), PFS was not statistically different between the two arms.

Conclusion: This trial demonstrates the clinical utility of CTC count as an objective decision tool when considering 1st line therapy in ER+ HER2- MBC. In most patients, CTC count did confirm the a priori clinical choice; however, trial results show that in discrepant cases, CTC count may be trusted for either escalating (i.e. considering CT in patients if high CTC count) or de-escalating (i.e. considering HT in patients if low CTC count) 1st line therapy.

Funding: French National Cancer Institute; Menarini Silicon Biosystems.

Citation Format: Bidard F-C, Jacot W, Dureau S, Brain E, Bachelot T, Bourgeois H, Goncalves A, Ladoire S, Naman H, Dalenc F, Gligorov J, Espie M, Levy C, Ferrero J-M, Loirat D, Cottu P, Dieras V, Simondi C, Berger F, Alix-Panabieres C, Pierga J-Y. Clinical utility of circulating tumor cell count as a tool to chose between first line hormone therapy and chemotherapy for ER+ HER2- metastatic breast cancer: Results of the phase III STIC CTC trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr GS3-07.

Abstract PD1-11: nextMONARCH 1: Phase 2 study of abemaciclib plus tamoxifen or abemaciclib alone in HR+, HER2- advanced breast cancer

Background

Abemaciclib is a selective CDK4 & 6 inhibitor approved on a continuous dosing schedule for HR+, HER2- advanced breast cancer (ABC) as monotherapy (MONARCH 1) and in combination with endocrine therapy (ET). A previous Phase 1b (NCT01394016) cohort of HR+ ABC patients (pts) demonstrated efficacy of abemaciclib monotherapy (150mg and 200mg Q12H starting dose); given the small sample size and nonrandomized design the impact of the starting dose was unclear. nextMONARCH 1 (NCT02747004) evaluated abemaciclib in 2 monotherapy arms, in a randomized setting. Abemaciclib has been associated with dose-dependent early onset diarrhea that is well managed with antidiarrheal therapy. nextMONARCH 1 also explored the 200mg Q12H abemaciclib dose in combination with prophylactic loperamide to reduce incidence/severity of diarrhea and dose adjustments. A third arm evaluated abemaciclib + tamoxifen as a strategy to overcome endocrine resistance.

Methods

nextMONARCH 1 is a multicenter, randomized, open-label, Phase 2 study of abemaciclib or abemaciclib + tamoxifen in women with HR+, HER2- ABC who have progressed on or after prior ET and previously received chemotherapy. Pts were stratified by presence of liver metastases and prior use of tamoxifen in the advanced setting. Randomization was 1:1:1 to abemaciclib 150mg Q12H + daily tamoxifen 20mg (Arm A) or abemaciclib 150mg Q12H (Arm B); or abemaciclib 200mg Q12H + prophylactic loperamide (Arm C). Key eligibilities were ≥2 chemotherapy regimens (1-2 administered in metastatic setting), measurable disease and no prior treatment with CDK4 & 6 inhibitors. Primary objective was progression free survival (PFS). Key secondary objectives included objective response rate (ORR), dclinical benefit rate (CBR), and safety. PFS analysis tested superiority of Arm A to C at ∼110 events across the 2 arms assuming a hazard ratio (HR) of 0.667 to achieve ∼80% power. Arm B would be considered non-inferior to Arm C if the observed PFS HR is &lt;1.2.

Results

234 pts were randomized to Arms A (n=78), B (n=79) and C (n=77). 166 PFS events have been observed (A: 57; B: 54; C: 55). Median PFS was 9.1 months in Arm A, 6.5 in Arm B and 7.4 in Arm C (A vs C: HR=.815, 95% CI, .556-1.193, p=.293; B vs C: HR=1.045, 95% CI, .711-1.535 p=.811). Investigator-assessed ORR was 34.6%, 24.1% and 32.5% (confirmed ORR: 25.6%, 19.0%, 28.6%) and CBR was 61.5%, 49.4% and 51.9% in Arms A, B and C, respectively. Prophylactic loperamide reduced the incidence and severity of diarrhea (C: 62.3%, Gr 3: 7.8%) compared to MONARCH 1 (90.2%, Gr 3: 19.7%, Dickler et al. 2017) resulting in similar rates of diarrhea with 150mg abemaciclib without prophylaxis (A: 53.8%, Gr 3: 1.3%; B: 67.1%, Gr 3: 3.8%). The adverse event profile across arms was generally consistent with other breast studies of abemaciclib.

Conclusions

nextMONARCH 1 confirmed single-agent activity of abemaciclib in heavily pretreated pts with HR+, HER2- ABC. Efficacy of abemaciclib monotherapy at 150mg was similar to 200mg. Combining tamoxifen with abemaciclib did not demonstrate a statistically significant improvement in PFS compared to abemaciclib monotherapy. Addition of prophylactic loperamide to abemaciclib 200mg resulted in diarrhea similar to 150mg without prophylaxis.

Citation Format: Hamilton E, Cortes J, Dieras V, Ozyilkan O, Chen S-C, Petrakova K, Manikhas A, Jerusalem G, Hegg R, Lu Y, Bear MM, Johnston EL, Martin M. nextMONARCH 1: Phase 2 study of abemaciclib plus tamoxifen or abemaciclib alone in HR+, HER2- advanced breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD1-11.

Abstract P6-18-19: Real-world survival of heavily pretreated patients with refractory HR+, HER2- metastatic breast cancer receiving single-agent chemotherapy - A comparison with MONARCH 1

Background

In MONARCH 1 (NCT02102490), abemaciclib demonstrated promising single-agent activity and tolerability in a population of heavily pretreated women with refractory HR+, HER2- metastatic breast cancer (MBC).1 Confirmed objective response rate (ORR) was 19.7% (95% CI: 13.3, 27.5) and at 18 months minimum follow-up median overall survival (OS) was 22.3 months. Due to the single-arm trial design of MONARCH 1, there is a need to view these results in clinical context relative to available treatment options. This study compared the OS results of abemaciclib in MONARCH 1 vs that in a real-world single-agent chemotherapy cohort with similar patient and disease characteristics.

Methods

MONARCH 1 study design and key eligibility criteria were previously described.1 The real-world cohort was based on Flatiron Health electronic health records-derived, nationally representative (USA-based) database comprising patient-level structured and unstructured data, curated via technology-enabled abstraction, for patients with MBC between January 1, 2011 through February 28, 2018. A real-world single-agent chemotherapy cohort was created based on the key eligibility criteria of MONARCH 1 and included patients diagnosed with HR+, HER2- MBC who received single-agent chemotherapy (eribulin, capecitabine, gemcitabine, or vinorelbine) following 1-2 prior chemotherapy regimens in the metastatic setting, had an ECOG PS of 0-1, and no prior CDK4 & 6 therapy. The index date was the start of the eligible single-agent chemotherapy, and patients were followed from the index date until date of death, loss to follow-up, or end of the database, whichever occurred earlier. OS results were adjusted using 2 methods (Mahalanobis distance matching and entropy balancing with bootstrapping) to account for baseline demographic and clinical differences between the real-world and trial cohorts.

Results

A real-world cohort (n=281) with eligibility criteria similar to the MONARCH 1 population (n=132) was identified. A subsequent matching based on Mahalanobis distance was performed to match MONARCH 1 population (n=108) with the real-world cohort (n=108). The matched cohorts demonstrated similar patient and disease characteristics. Median OS was 22.3 months in the abemaciclib arm vs 13.6 months in the matched cohort with an estimated hazard ratio (HR) of 0.54 (95% CI: 0.37, 0.77). Results of a sensitivity analysis performed using entropy balancing were consistent with an adjusted median OS of 12.7 months in the real-world cohort (n=281)with HR of 0.57 (95% CI from bootstrapping: 0.44, 0.78).

Conclusion

Methodological advances to adjust for potential biases, and improvements in data quality, have evolved enabling the ability to leverage a real-world cohort as an external comparator arm. This study demonstrates the ability to create a real-world chemotherapy cohort suitable to serve as a comparator for MONARCH 1. These exploratory results suggest a survival advantage and adequately place the clinical benefit of abemaciclib monotherapy in clinical context.

References

Dickler et al, CCR 2017

Citation Format: Rugo H, Dieras V, Cortes J, Patt D, Wildiers H, O'Shaughnessy J, Zamora E, Yardley DY, Carter GC, Sheffield KM, Li L, Andre VA, Derbyshire RE, Li XI, Frenzel M, Huang Y-J, Dickler MN, Tolaney SM. Real-world survival of heavily pretreated patients with refractory HR+, HER2- metastatic breast cancer receiving single-agent chemotherapy - A comparison with MONARCH 1 [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-19.

Abstract OT3-05-06: EarLEE-2: A phase 3 study of ribociclib + endocrine therapy (ET) for adjuvant treatment of patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2–), intermediate-risk, early breast cancer (EBC)

Background: Adjuvant ET with or without chemotherapy reduces the risk for recurrence of HR+, HER2– EBC. However, recurrence is still common, especially in patients with adverse clinical and pathologic features. In the phase 3 MONALEESA-2 trial, the cyclin-dependent kinase 4/6 inhibitor ribociclib (LEE011), in combination with letrozole, prolonged progression-free survival versus letrozole plus placebo in postmenopausal women with HR+, HER2– advanced breast cancer and no prior therapy for advanced disease (HR = 0.56, 95% CI, 0.43-0.72; P = 3.29×10−6; Hortobagyi et al. N Engl J Med. 2016). EarLEE-2 is investigating the efficacy and safety of ribociclib with ET versus placebo with ET as adjuvant treatment in patients with intermediate-risk EBC.

Trial design: In this double-blind, placebo-controlled, phase 3 adjuvant trial, ˜4,000 women and men with fully resected, intermediate-risk, HR+, HER2– EBC (defined as AJCC 8th ed. Prognostic Stage Group II) are being randomized 1:1 to oral ribociclib (600 mg/day, 3 weeks on/1 week off for ˜24 months) plus ET or to placebo plus ET. Adjuvant ET may include tamoxifen, letrozole, anastrozole, or exemestane for ≥ 60 months with ovarian suppression for premenopausal women at the discretion of the investigator. Adjuvant ET in men will be tamoxifen only. Neoadjuvant therapy is not permitted. Randomization is stratified by menopausal status (men and premenopausal women vs postmenopausal women), prior adjuvant chemotherapy (yes vs no), Prognostic Stage Group (IIA vs IIB), and geographic region (North America/Europe/Australia vs rest of the world). Eligible patients must have tumor tissue from the surgical specimen, adequate bone marrow and organ functions, normal serum electrolytes, QTc interval &lt; 450 msec, and completed and recovered from acute toxicities of adjuvant radiotherapy and/or chemotherapy. The primary endpoint is invasive disease-free survival (per STEEP system; Hudis et al. J Clin Oncol. 2007). Secondary endpoints include recurrence-free survival, distant disease-free survival, overall survival, quality of life, and safety. Global recruitment to EarLEE-2 is ongoing. NCT03081234

Citation Format: O'Shaughnessy J, Alba E, Bardia A, Dent S, Dieras V, Hortobagyi G, Im S-A, Montemurro F, Untch M, Yardley DA, Chakravartty A, Germa C, Miller M, Slamon D. EarLEE-2: A phase 3 study of ribociclib + endocrine therapy (ET) for adjuvant treatment of patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2–), intermediate-risk, early breast cancer (EBC) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT3-05-06.

Abstract P5-19-01: Impact of palbociclib plus letrozole on patient-reported general health status compared with letrozole alone in ER+/HER2- advanced/metastatic breast cancer

BACKGROUND: Palbociclib plus letrozole significantly improved progression-free survival (PFS) compared with letrozole plus placebo in treatment-naive postmenopausal patients with estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (MBC) in the phase 3 PALOMA-2 trial. Here, we compare patient-reported general health status with extended (max 53 cycles) follow-up (data cut off May31st, 2017) (Pfizer: NCT01740427).

METHODS: PALOMA-2 randomized patients 2:1 to palbociclib + letrozole (n=444) or placebo + letrozole (n=222). Patient-reported outcomes were assessed at baseline, day 1 of cycles 1, 2, and 3, and day 1 of every other cycle from cycle 5 until the end of treatment using the EuroQol 5-Dimension Questionnaire (EQ-5D). The EQ-5D is a standardized measure of health status that consists of a descriptive system comprising the following 5 dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression rated at 3 levels (no, some, or extreme problems) and a single index score for health status (ranges generally from 0 [dead] to 1 [full health]) calculated using a standard algorithm. In addition, a visual analog scale (VAS) measured self-rated health status from 0 (worst imaginable) to 100 (best imaginable). Repeated measures mixed-effects analyses were performed to compare overall index and VAS scores between treatments, controlling for baseline.

RESULTS: Completion rates at baseline were &gt;95% in each group. The mean (SD) scores at baseline were comparable between palbociclib plus letrozole and letrozole alone for the VAS (71.3 [21.2] vs 72.3 [19.8]) and the EQ-5D index scores (0.70 [0.25]) vs (0.73 [0.21]). Median follow up was 38 months for palbociclib plus letrozole and 37 months for letrozole only. No statistically significant difference in overall change from baseline in general health status was observed between the treatment arms. The proportion of patients reporting the presence of a problem at baseline was similar for palbociclib plus letrozole and letrozole, respectively: mobility (39% vs 39%), self-care (12% vs 12%), usual activities (44% vs 39%), pain (69% vs 65%), and anxiety/depression (54% vs 54%). No statistically significant difference in overall mean EQ-5D index scores (0.73 vs. 0.71) was observed between the treatment arms.

CONCLUSION: Addition of palbociclib to letrozole maintained general health status and EQ-5D index scores in ER+ HER2- advanced/metastatic breast cancer with no statistically significant differences observed compared to letrozole alone.

Citation Format: Harbeck N, Dieras V, Finn R, Gelmon KA, Walshe JM, Shparyk Y, Mori A, Lui DR, Bhattacharyya H, Iyer S, Johnston S, Rugo HS. Impact of palbociclib plus letrozole on patient-reported general health status compared with letrozole alone in ER+/HER2- advanced/metastatic breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-19-01.

Abstract P5-20-03: Impact of prior adjuvant trastuzumab (aT) on clinical characteristics, patterns of recurrence and outcome in 2863 patients with Her2 positive (HER2+) metastatic breast cancer (MBC)- Results from the French ESME UNICANCER program

Background: The management of HER2+ BC has changed dramatically with the introduction and widespread use of HER2-targeted therapies, especially in the adjuvant setting. However, there is relatively limited real-world information on the impact of adjuvant Trastuzumab (aT) on patterns of recurrence and outcome of HER2+ MBC.

Methods: In 2014, the 18 French Cancer Centers launched the Epidemiological Strategy and Medical Economics (ESME) program to provide real-world data on MBC patients (pts). All pts who started a 1st-line treatment for MBC between 01-Jan-2008 and 31-Dec-2014 were included. We examined clinical characteristics and outcomes (overall survival [OS] and time to next treatment [TNT]) in patients with HER2+ MBC pretreated with trastuzumab in the adjuvant setting (aT) compared with trastuzumab-naïve patients (nT) and patients with de novo HER2+ MBC (dn). Multivariate analyses adjusted for baseline demographic, prognostic factors and year of diagnosis (prior or after 2005, when aT was approved and widely administered in France for early HER2+ breast cancer).

Results: Among the 15170 pts of the ESME database, 2863 (19%) were HER2+: 1093 pts (38%) had de novo and 1765 pts (62%) recurrent MBC; 63% were Hormone Receptor (HR) +; 54%, 25% and 21% had respectively 1, 2, or &gt; 2 metastatic sites (68% visceral and 12% brain). Median time to 1st metastasis was 43.4 months (m) (95% CI: 24.6-84.4): 54 m in HR+ and 30 m in HR-. Among pts with recurrent MBC, 55% (995) had received aT. As 1st-line therapy for MBC, 90 % of pts received HER2-targeted agents (73% T-based). With a median follow-up of 46 m, median OS is 45 m (95% CI: 42.5-48). OS is significantly higher in de novo compared to recurrent MBC: 54 m (95% CI: 50.2-60.4) vs. 38.4 m (95% CI: 36.7-41.9), (p &lt; 0.0001). Among pts with recurrent cancers, median OS is inferior in pts who had received aT, as compared to those who had not: 33.4 m (95% CI: 29.6-36.7) vs. 49.5 m (95% CI: 44.3-56.8), (p &lt; 0.0001). Statistically significant differences persist after adjustment for age at MBC, disease-free interval, metastatic sites and RH status in the multivariate model (HR=1.45, 95% CI: 1.26-1.67) but not after adjustment for year of diagnosis (prior or after 2005) (HR=0.90, 95% CI: 0.70-1.15).

Conclusions: These large-scale real-world data in patients with HER2+ MBC provide evidence that the survival outcome remain similar in patients with failure of adjuvant trastuzumab compared with trastuzumab-naïve patients after adjustment for year of diagnosis. De novo HER2+ MBC pts have the best outcomes. Data on clinical characteristics of metastasis and time to next treatment for the three subgroups will be presented at the meeting.

Citation Format: Saghatchian M, Carton M, Piot I, Pérol D, Pistilli B, Brain E, Ghouadni A, Ricci F, Vanlemmens L, Loeb A, Levy C, Goncalves A, Dalenc F, Lefeuvre-Plesse C, Campone M, Jaffre A, Gourgou S, Cailliot C, Robain M, Dieras V. Impact of prior adjuvant trastuzumab (aT) on clinical characteristics, patterns of recurrence and outcome in 2863 patients with Her2 positive (HER2+) metastatic breast cancer (MBC)- Results from the French ESME UNICANCER program [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-20-03.

Abstract P1-17-03: Abemaciclib for the treatment of brain metastases secondary to hormone receptor positive breast cancer

Background: Although a lower percentage of patients with hormone receptor-positive (HR+) metastatic breast cancer (MBC) develop brain metastases when compared with triple negative and HER2+ MBC patients, there are no regulatory approved systemic agents for the treatment of HR+ breast cancer brain metasteses, and this remains an unmet medical need. Standard local treatment options include surgery, stereotactic radiosurgery (SRS), and/or whole brain radiation therapy (WBRT). Abemaciclib, an oral selective CDK4 and 6 inhibitor administered on a continuous dosing schedule, has demonstrated clinical activity and an acceptable safety profile in heavily pre-treated HR+ MBC patients. Preclinically, abemaciclib crosses the blood-brain barrier, which is further supported clinically by detectable levels of abemaciclib similar to plasma levels in resected brain metastases in a subset of patients with HR+, HER2- MBC as previously reported for the current study. Together these data provide further rationale for evaluating abemaciclib in patients with brain metastases.

Methods: Study I3Y-MC-JPBO (NCT02308020) is an open-label, Phase 2, Simon 2-Stage trial evaluating the safety and efficacy of abemaciclib up to 200 mg BID in 4 cohorts of patients with brain metastases secondary to HR+ MBC, NSCLC, or melanoma. With regard to HR+ MBC, one cohort included HR+, HER2- patients, another one included HR+/HER2+ patients. All HR+ MBC patients enrolled to 1 of these 2 cohorts were required to have at least 1 measurable brain lesion. The primary objective was objective intracranial response rate as defined by Response Assessment in Neuro-Oncology brain metastases response criteria. Stage 1 was to enroll 23 evaluable patients per study part; if ≥2 respond to abemaciclib, 33 additional evaluable patients were to be enrolled to Stage 2. Secondary CNS objectives include best overall response, duration of response, and clinical benefit rate.

Results: For Stage 1 efficacy, in patients with HR+, HER2+ MBC futility was met. However, for HR+, HER2- patients, 2 confirmed, durable partial responses were observed and enrollment to Stage 2 is ongoing.

Conclusions: Previously, this study provided evidence that abemaciclib penetrates brain metastases in patients with HR+, HER2- MBC. The current results provide sufficient evidence of anti-tumor activity on brain metastases in patients with HR+, HER2- MBC to merit further exploration, but not for patients with HR+, HER2+ disease. Safety and tolerability results are similar to those previously reported for abemaciclib, with the majority of adverse events being gastrointestinal.

Citation Format: Bachelot T, Kabos P, Yardley D, Dieras V, Costigan T, Klise S, Awada A. Abemaciclib for the treatment of brain metastases secondary to hormone receptor positive breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-17-03.

Abstract P5-21-03: Palbociclib (PAL) + letrozole (LET) as first-line therapy in estrogen receptor–positive (ER+)/human epidermal growth factor receptor 2–negative (HER2−) advanced breast cancer (ABC): Efficacy and safety updates with longer follow-up across patient subgroups

BACKGROUND: Endocrine therapy (ET) has been the primary first-line (1L) therapy for ER+ ABC. In the PALOMA-2 study (NCT01740427), PAL (P)+LET (L) significantly prolonged progression-free survival (PFS; HR=0.58, P&lt;.001) after a median 23 mo follow-up (FU) (Finn et al. NEJM 2016). Here we report more mature PFS overall and in subgroups, with (w/) longer FU. The study is ongoing for overall survival FU.

METHODS: Postmenopausal pts w/ ER+/HER2- ABC and no prior systemic therapy in the ABC setting were randomized 2:1 to P (125 mg/d) + L (2.5 mg QD) or placebo (PBO) + L. Key endpoints: investigator-assessed PFS and safety. Median PFS (mPFS) was estimated (intent-to-treat population).

RESULTS: 666 pts (444, P+L; 222, PBO+L) were enrolled. Arms were well balanced: visceral (48%)/nonvisceral (52%) disease and prior ET (56%)/no prior ET (44%). After a median FU of 38 mo w/ P+L and 37 mo w/ PBO+L, mPFS was 27.6 and 14.5 mo, respectively, in the overall population (HR=0.56, P&lt;.0001; Table).

TABLE. mPFS overall and by relevant subgroupsP+LPBO+LP+L vs PBO+LmPFS, mo (95% CI)mPFS, mo (95% CI)HR (95% CI)P* Overall27.6 (22.4–30.3)14.5 (12.3–17.1)0.56 (0.46–0.69)&lt;.0001 Measurable disease23.7 (19.3–27.6)14.5 (12.3–18.5)0.63 (0.50–0.79)&lt;.0001 Nonmeasurable disease36.2 (27.6?NE)16.5 (8.3–19.6)0.39 (0.25–0.60)&lt;.0001 Visceral19.3 (16.4–24.2)12.3 (8.4–16.4)0.62 (0.47–0.81)&lt;.0005 Nonvisceral35.9 (27.7–NE)17.0 (13.8–24.8)0.50 (0.37–0.67)&lt;.0001 Bone only†36.2 (27.6–NE)11.2 (8.2–22.0)0.41 (0.26–0.63)&lt;.0001 Not bone only24.2 (19.4–27.7)14.5 (12.9–18.5)0.62 (0.50–0.78)&lt;.0001 De novo metastatic27.9 (22.1–33.4)22.0 (13.9–27.4)0.61 (0.44–0.85)&lt;.005 Prior ET24.2 (18.8–27.6)11.2 (8.4–14.5)0.54 (0.42–0.71)&lt;.0001 No prior ET30.3 (24.5–35.7)21.9 (15.9–27.4)0.59 (0.43–0.80)&lt;.0005 Nonvisceral36.2 (27.9–NE)27.6 (19.1–35.6)0.59 (0.38–0.92)&lt;.01 Visceral23.7 (16.8–30.3)13.9 (10.2–22.2)0.55 (0.36–0.85)&lt;.005 Disease sites130.4 (24.8–NE)16.5 (11.0–22.1)0.52 (0.36–0.75)&lt;.0005228.1 (19.4–NE)16.3 (11.0–27.4)0.57 (0.37–0.89)&lt;.01323.7 (19.2–27.6)13.8 (8.8–17.0)0.61 (0.46–0.82)&lt;.0005NE=not estimable. *Not adjusted for multiple analyses; 1-sided P values. †Per tumor site.

All subgroups benefited from addition of P to L. Notably, pts w/ low disease burden (bone only, nonvisceral disease, few disease sites) derived significant PFS benefit, including those w/ both nonvisceral disease and no prior ET (mPFS, 36.2 vs 27.6 mo; HR=0.59, P&lt;.01). Importantly, median time from randomization to start of 2nd subsequent systemic anticancer therapy was 39 vs 29 mo for P+L vs PBO+L (HR=0.72, P&lt;.005). There were no new safety signals w/ longer FU.

CONCLUSIONS: This is the longest FU of a phase 3 study of a cyclin-dependent kinase 4/6 inhibitor for ABC. P+L continues to consistently improve PFS vs PBO+L across all subgroups while toxicity remains manageable; notably P+L delays time to starting 2nd subsequent anticancer therapies by 10 mo. Pts w/ low disease burden or sensitivity to ET alone had PFS &gt;3 y (significant vs PBO+L), demonstrating the clinical benefit of P+ET. These data confirm P+L should be a 1L therapy option for pts w/ HR+/HER2- ABC.

Funding: Pfizer

Citation Format: Rugo HS, Finn RS, Dieras V, Ettl J, Lipatov O, Joy A, Harbeck N, Castrellon A, Lu DR, Mori A, Gauthier ER, Huang C, Gelmon KA, Slamon DJ. Palbociclib (PAL) + letrozole (LET) as first-line therapy in estrogen receptor–positive (ER+)/human epidermal growth factor receptor 2–negative (HER2−) advanced breast cancer (ABC): Efficacy and safety updates with longer follow-up across patient subgroups [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-21-03.

Abstract P6-11-13: Phase Ib study evaluating the safety and clinical activity of lumretuzumab combined with pertuzumab and paclitaxel in HER2-low metastatic breast cancer

Background: Inhibition of HER2 and HER3 heterodimerisation is a novel treatment concept in HER2-”low” expressing breast cancer (BC). Lumretuzumab, a glycoengineered monoclonal anti-HER3 antibody, in combination with pertuzumab has demonstrated synergistic anti-tumor activity in preclinical HER2–low expressing preclinical BC models.

Methods: This open-label, multicenter phase I study selectively enrolled metastatic BC patients (pts) expressing HER3 protein and low levels of HER2 (defined as IHC 1+ and 2+ and ISH-negative) in a formalin-fixed paraffin-embedded pretreatment tumor biopsy sample. Eligible pts were treated with a combination of paclitaxel (PA) qw plus lumretuzumab (L) and pertuzumab (P) q3w in three dose cohorts. The safety, antitumor activity and tumor biomarkers including protein expression (IHC, MS) and mutational data (NGS) in association with clinical activity were evaluated.

Results: Overall, 35 pts were included in this study. The median age was 60 (range: 33 to 77) years. The median number of prior treatments for metastatic disease ranged from 0 to 5 with 23 pts (65.7%) without prior chemotherapy for metastatic disease. Cohort 1 was treated with PA at 80 mg/m2, L at 1000 mg and P at 840 mg for Cycle 1 followed by 420 mg for the following cycles. This cohort was stopped after two pts both experienced grade 3 diarrhea within the first treatment cycle which was considered a dose-limiting toxicity (DLT). For Cohort 2 the dose of L was reduced to 500 mg based on PK modelling and simulation data. No DLTs were seen for the first 6 pts. A total of 20 pts were recruited with an objective response rate (ORR) and disease control rate (DCR) of 30% and 75%, respectively, and 56% and 78%, respectively, for 1st-line pts (n=9) in this cohort. Diarrhea (≥G3) and hypokalemia (≥G3) occurred in 50% and 55% of pts, respectively, and all pts experienced chronic diarrhea throughout the course of treatment. For Cohort 3 the dose of L was maintained at 500 mg, PA at 80 mg/m2, and P was administered at 420 mg at all cycles. In addition, a prophylactic loperamide regimen was introduced. Altogether, 13 pts - all 1st-line for metastatic disease - were treated. No DLTs were seen for the first 6 pts. Diarrhea (≥G3) and hypokalemia (≥G3) were reduced to 31% and 15%, respectively, but chronic diarrhea was still observed throughout the treatment in all pts. The ORR and DCR were 31% and 77%, respectively. Preliminary mechanistic safety experiments revealed HER2/HER3-dependent chloride channels in the intestine as likely cause of diarrhea. Biomarker data will be presented along with updated clinical and safety data.

Conclusions: The combination of L, P and PA was associated with high rates of persistent diarrhea. Dose modifications and prophylactic anti-diarrheal medication led to significantly reduced diarrhea intensity but did not change the incidence and persistence of diarrhea overall. Despite encouraging clinical activity especially in 1st line pts, the therapeutic window of this combination is too low to warrant further clinical development.

Citation Format: Schneeweiss A, Park-Simon T-W, Albanell J, Lassen U, Cortes J, Dieras V, May M, Schindler C, Marmé F, Cejalvo JM, Martinez-Garcia M, Gonzalez I, Lopez-Martin J, Welt A, Joly F, Michielin F, Jacob W, Adessi C, Moisan A, Meneses-Lorente G, James I, Ceppi M, Hasmann M, Weisser M, Cervantes A. Phase Ib study evaluating the safety and clinical activity of lumretuzumab combined with pertuzumab and paclitaxel in HER2-low metastatic breast cancer [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 P6-11-13.

Abstract OT1-02-03: Phase I multicenter clinical trial evaluating the combination of trastuzumab emtansine (T-DM1) and non-pegylated liposomal doxorubicin (NPLD) in HER2-positive metastatic breast cancer (MBC) (MEDOPP038 study)

BACKGROUND:

Clinical efficacy and safety of T-DM1 for the treatment of HER2-positive MBC has been assessed in several phase II and III trials and is now considered the standard of care in taxane-and trastuzumab-progressing patients. However, although T-DM1 has shown encouraging antitumor activity in the advanced setting, several strategies to improve T-DM1 efficacy are currently evaluated, including the combination with non-pegylated liposomal doxorubicin (NPLD), considering that: i) doxorubicin is one of the most active chemotherapeutic agents against HER2-positive breast cancer; ii) the combination of doxorubicin and trastuzumab induces synergistic antitumor activity in HER2-overexpressing preclinical models; and iii) liposomal formulations of doxorubicin have a reduced risk of developing cardiac toxicity.

OBJECTIVES:

The primary objective of this trial is to determine the maximum tolerated dose (MTD) of the combination of T-DM1 and NPLD in patients with HER2-positive MBC naïve of anthracyclines and previously treated with trastuzumab and a taxane. The secondary objectives include 1) safety, with special emphasis on cardiac safety evaluated by left ventricular ejection fraction, high-sensitivity troponin I and B-type natriuretic peptide (BNP) levels, 2) pharmacokinetics, 3) antitumor activity, and the 4) role of single nucleotide polymorphisms of HER2 gene for developing cardiotoxicity.

TRIAL DESIGN:

This is a dose-finding, open-label, non-randomized and multicenter phase I clinical trial of T-DM1 at a fixed dose of 3.6 mg/kg IV in combination with three different dose levels (DL) of NPLD (45, 50, and 60 mg/m2) IV administered on Day 1 every three weeks. The trial follows a modified dose escalation scheme with a 3+3 design.A total of three patients will be included in the first cohort and observed for dose-limiting toxicities (DLTs) during the first two cycles of treatment. If none of these patients experiences a DLT, three other patients will be treated at the next DL. However, in case of at least one patient experiences a DLT, three more patients will be treated at the same DL. The MTD will be defined as the highest DL at which ≤1 of six patients experiences a DLT during the first two cycles of treatment. An expansion cohort of six additional patients at the MTD will be included.

ELIGIBILITY:

Anthracycline-naïve patients with HER2-positive MBC and up to two prior chemotherapy regimens in the advanced setting who previously were treated with trastuzumab and a taxane. ECOG performance status of 0-1. Adequate organ and cardiovascular function with LVEF ≥ 55%. RECIST v1.1 evaluable disease.

ACCRUAL:

A total of 12-24 patients will be enrolled at four sites in Spain and France. Recruitment was opened on September 2015. To date, four patients (three at DL1 and one at DL2) have been recruited.

Citation Format: López-Miranda E, Brain E, Saura C, Gligorov J, Dubot C, Dieras V, Suter TM, Aguirre E, Perez-García JM, Llombart A, Cortés J. Phase I multicenter clinical trial evaluating the combination of trastuzumab emtansine (T-DM1) and non-pegylated liposomal doxorubicin (NPLD) in HER2-positive metastatic breast cancer (MBC) (MEDOPP038 study) [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 OT1-02-03.

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

BACKGROUND

Bevacizumab combined with paclitaxel as first-line chemotherapy for patients with HER2-negative metastatic breast cancer (MBC) has led to mixed results in randomized trials, with an improvement in progression-free survival (PFS) but no statistically significant overall survival (OS) benefit. Real-life data could help in assessing the value of this combination.

PATIENTS AND METHODS

This study aimed to describe the outcome following first-line paclitaxel with or without bevacizumab in the French Epidemiological Strategy and Medical Economics (ESME) database of MBC patients, established in 2014 by Unicancer. The primary and secondary end points were OS and PFS, respectively.

RESULTS

From 2008 to 2013, 14 014 MBC patient files were identified, including 10 605 patients with a HER2-negative status. Of these, 3426 received paclitaxel and bevacizumab (2127) or paclitaxel (1299) as first-line chemotherapy. OS adjusted for major prognostic factors was significantly longer in the paclitaxel and bevacizumab group compared with paclitaxel [hazard ratio (HR) 0.672, 95% confidence interval (CI) 0.601-0.752; median survival time 27.7 versus 19.8 months]. Results were consistent in all supportive analyses (using a propensity score for adjustment and as a matching factor for nested case-control analyses) and sensitivity analyses. Similar results were observed for the adjusted PFS, favoring the combination (HR 0.739, 95% CI 0.672-0.813; 8.1 versus 6.4 months).

CONCLUSIONS

In this large-scale, real-life setting, patients with HER2-negative MBC who received paclitaxel plus bevacizumab as first-line chemotherapy had a significantly better OS and PFS than those receiving paclitaxel. Despite robust methodology, real-life data are exposed to important potential biases, and therefore, results need to be treated with caution. Our data cannot therefore support extension of current use of bevacizumab in MBC.

Abstract P2-02-17: T-DM1 in HER2-negative metastatic breast cancer patients with HER2-amplified circulating tumor cells: Current status of the CirCe T-DM1 phase II trial

Background: Liquid biopsy can reassess key therapeutic targets in metastatic breast cancer. Several studies showed that a low albeit significant rate of metastatic breast cancer initially considered as HER2-negative can be reclassified as HER2-positive by systematic biopsy procedures. We report here the current status of the CirCe T-DM1 trial [NCT01975142] which aims to demonstrate the clinical utility of HER2 status reassessment on circulating tumor cells (CTCs).

Methods: The first step of the trial consists in CTC count and HER2/CEP17 FISH on detected CTCs (CellSearch, Janssen Diagnostics) in patients (pts) with measurable disease progressing after the second line of chemotherapy. Pts with amplified CTCs (HER2/CEP17 ratio equal or higher than 2.2) are eligible to the treatment step of the study in two distinct cohorts: low CTC count (1 or 2 HER2-amplified CTCs) and high CTC count (3 and more HER2-amplified CTCs). In the treatment step has a Simon's two stage design, the anti-HER2 antibody-drug conjugate T-DM1 being administered until tumor progression. The primary objective of the trial is the confirmed response rate (RECIST). This trial is supported by Roche.

Results: CirCe T-DM1 has been initiated in 10 centers in France. As of June 2015, 105 metastatic breast cancers pts considered as HER2-negative were screened. 29 pts (27%) had no CTC detected, 68 pts (65%) had at least 1 CTC detected with no HER2 amplification, and 8 pts (8%) exhibited HER2-amplified CTCs. Among the 8 pts, 1 pt had 5 HER2-amplified CTC, 2 pts had 2 HER2-amplified CTC and 5 pts had 1 HER2-amplified CTC. HER2/CEP17 ratios among HER2-amplified CTCs ranged from 2.5 to 7. Five of the 8 pts were treated by T-DM1. One objective confirmed partial tumor response has been observed (20%).

Conclusion: The accrual is ongoing; the first efficacy assessment will occur after having treated 14 pts. This innovative trial highlights the promise and the complexity of liquid biopsy-based programs in the era of precision medicine: scarcity of the target, reliability and reproducibility of the target assessment, major efficacy when the target is matched to the appropriate drug.

Citation Format: Bidard F-C, Romieu G, Jacot W, Cottu P, Dieras V, Lerebours F, Servent V, Luporsi E, Lortholary A, Tubiana-Mathieu N, Espie M, Bollet M, Bourgeois H, Renaud N, Pelissier S, Armanet S, Baeten K, Pierga J-Y. T-DM1 in HER2-negative metastatic breast cancer patients with HER2-amplified circulating tumor cells: Current status of the CirCe T-DM1 phase II trial. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-02-17.

REBECA: a phase I study of bevacizumab and whole-brain radiation therapy for the treatment of brain metastasis from solid tumours

BACKGROUND

Brain metastases (BMs) are associated with a poor prognosis. Standard treatment comprises whole-brain radiation therapy (WBRT). As neo-angiogenesis is crucial in BM growth, combining angiogenesis inhibitors such as bevacizumab with radiotherapy is of interest. We aimed to identify the optimal regimen of bevacizumab combined with WBRT for BM for phase II evaluation and provide preliminary efficacy data.

PATIENTS AND METHODS

In this multicentre single-arm phase I study with a 3 + 3 dose-escalation design, patients with unresectable BM from solid tumours received three cycles of bevacizumab at escalating doses [5, 10 and 15 mg/kg every 2 weeks at dose levels (DL) 0, 1 and 2, respectively] and WBRT (30 Gy/15 fractions/3 weeks) administered from day 15. DL3 consisted of bevacizumab 15 mg/kg with WBRT from day 15 in 30 Gy/10 fractions/2 weeks. Safety was evaluated using NCI-CTCAE version 3. BM response (RECIST 1.1) was assessed by magnetic resonance imaging at 6 weeks and 3 months after WBRT.

RESULTS

Nineteen patients were treated, of whom 13 had breast cancer. There were no DLTs. Grade 1-2 in-field and out-field toxicities occurred for five and nine patients across all DLs, respectively, including three and six patients (including one patient with both, so eight patients overall) of nine patients in DL3. One patient experienced BM progression during treatment (DL0). At the 3-month post-treatment assessment, 10 patients showed a BM response: one of three treated at DL0, one of three at DL1, two of three at DL2 and six of seven at DL3, including one complete response. BM progression occurred in five patients, resulting in two deaths. The remaining patient died from extracranial disease progression.

CONCLUSION

Bevacizumab combined with WBRT appears to be a tolerable treatment of BM. DL3 warrants further efficacy evaluation based on the favourable safety/efficacy balance. ClinicalTrials.gov Identifier: NCT01332929.

A phase I pharmacokinetic study of the vascular disrupting agent ombrabulin (AVE8062) and docetaxel in advanced solid tumours

BACKGROUND

The vascular disrupting agent ombrabulin shows synergy with docetaxel in vivo. Recommended phase II doses were determined in a dose escalation study in advanced solid tumours.

METHODS

Ombrabulin (30-min infusion, day 1) followed by docetaxel (1-h infusion, day 2) every 3 weeks was explored. Ombrabulin was escalated from 11.5 to 42 mg m(-2) with 75 mg m(-2) docetaxel, then from 30 to 35 mg m(-2) with 100 mg m(-2) docetaxel. Recommended phase II dose cohorts were expanded.

RESULTS

Fifty-eight patients were treated. Recommended phase II doses were 35 mg m(-2) ombrabulin with 75 mg m(-2) docetaxel (35/75 mg m(-2); 13 patients) and 30 mg m(-2) ombrabulin with 100 mg m(-2) docetaxel (30/100 mg m(-2); 16 patients). Dose-limiting toxicities were grade 3 fatigue (two patients; 42/75, 35/100), grade 3 neutropaenic infection (25/75), grade 3 headache (42/75), grade 4 febrile neutropaenia (30/100), and grade 3 thrombosis (35/100). Toxicities were consistent with each agent; mild nausea/vomiting, asthaenia/fatigue, alopecia, and anaemia were common, as were neutropaenia and leukopaenia. Diarrhoea, nail disorders and neurological symptoms were frequent at 100 mg m(-2) docetaxel. Pharmacokinetic analyses did not show any relevant drug interactions. Ten patients had partial responses (seven at 30 mg m(-2) ombrabulin), eight lasting >3 months.

CONCLUSIONS

Sequential administration of ombrabulin with 75 or 100 mg m(-2) docetaxel every 3 weeks is feasible.

Abstract P3-15-04: A French prospective pilot study to identify dihydropyrimidine dehydrogenase (DPD) deficiency in breast cancer patients receiving capecitabine

Background: Health Authorities point out that DPD deficiency confers a significant risk of major toxicity for patients receiving capecitabine. Identification of at-risk patients is thus of major concern. This multicentric prospective study of the French GPCO group (Groupe de Pharmacologie Clinique Oncologique, Unicancer) evaluated the sensitivity, specificity and predictive values of DPD phenotyping and genotyping to predict severe cap-related toxixity in metastatic breast cancer patients.

Methods: 303 patients were included between February 2009 and February 2011 (15 institutions). Eighty-eight% received capecitabine as monotherapy, 28% were treated as first line (mean dose at 1st cycle 1957 mg/m2/d). Pre-treatment uracil (U, physiological DPD substrate) plasma concentration was measured in 286 patients (HPLC assay). DPD genotyping (IVS14+1G&gt;A, 2846A&gt;T, 1679T&gt;G, 464T&gt;A) was performed on 281 patients. Severe toxicity (G3-4 CTCAE v3 criteria) was measured over cycles 1-2.

Results: Grade 3-4 toxicity (diarrhea, vomiting, hematoxicity, hand-foot syndrome) has been observed in 19.6% of patients (one toxic death). A marked trend for higher U concentrations has been noted in patients developing severe toxicity vs those who didn't (median 12.7 ng/ml (Q1-Q3 9-17) vs median 10.2 ng/ml (range 8-13), respectively, p = 0.014). However, ROC curve has showed that this difference was too small for use as a reliable toxicity predictor. The patient with toxic death had an elevated U concentration at 17 ng/ml. Among the 7 patients with a DPD mutation (3 pts IVS14+1, 3 pts 2846A&gt;T, one 1679T&gt;G, all heterozygous), 5 developed severe toxicity (including the toxic death, 2846A&gt;T), one did not, and the last one was not documented. Relative risk for developing severe toxicity was 4.60 in mutated patients vs wild-type patients (95%CI 2.95-7.16, p = 0.001); positive and negative predictive values were 83.3% and 81.9%, respectively; specificity was 99.5% and sensitivity was 9.8%.

Conclusions: Breast cancer patients harbouring a DPD variant allele are at risk to develop severe, up to lethal, capecitabine-related toxicity. Pre-treatment U measurement remains to be more firmly established as a reliable predictor of capecitabine toxicity. These observations are of major interest for breast cancer patients candidate for capecitabine therapy.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-15-04.

Abstract OT1-1-10: CirCe T-DM1 phase II trial: Assessing the relevance of HER2-amplified circulating tumor cells as a tool to select HER2-negative metastatic breast cancer for treatment with T-DM1

Background: T-DM1 has demonstrated its efficacy in the second line of HER2-positive metastatic breast cancer patients. Several studies reported that some breast cancers considered as HER2-negative do have HER2-positive circulating tumor cells (CTC). Our previous report (Lightart & Bidard, Ann Oncol 2013) showed that the reliability of such discrepancy between primary tumor and CTC is directly related to the number of CTC analyzed. This study aims at studying the efficacy of T-DM1 in this setting.

Trial design: CirCe T-DM1 is a single arm two-step phase II multicenter study with adaptive design. Patients with HER2-negative measurable metastatic breast cancer will be screened by the FDA-approved CellSearch system, before the start of a second line treatment. HER2/CEP17 ratio will be quantified by FISH on CTC (Veridex). Patients with non HER2-amplified CTC or no CTC will be excluded from the study. Patients with HER2-amplified CTC will be treated by T-DM1 (Roche) single agent q3w, in either cohort “L” (low count: 1 to 4 HER2-amplified CTC) or in cohort “H” (high count: 5 or more HER2-amplified CTC). 14 patients (7L+7H) will be included in the first step. If needed, the second step will include 14 additional patients (7L+7H). Tumor response (per RECIST criteria) is the main objective of the trial.

Eligibility criteria: main criteria are HER2-negative metastatic breast cancer; measurable disease progressing after a first line treatment; PS 0-1; criteria related to T-DM1 treatment and ethics. Only patients with HER2-positive CTC will be treated by t-DM1.

Specific aim: this study will assess the response rate to T-DM1 in patients with HER2-amplified CTC and HER2-negative metastatic breast cancer, taking into account the number of HER2-amplified CTC detected (1-4 or 5+).

Statistical methods: To design this adaptive study, response rates were estimated to be H0 = 5% (no efficacy of T-DM1) and H1 = 25% (efficacy of T-DM1). After the first step (N = 7L and 7H patients): if no response is seen, the trial will be stopped, and considered as negative; if 3 or more responses are seen, we will conclude that the CTC FISH test is relevant to select patient for T-DM1 treatment, in either the L or/and H population, according to the observed pattern of responses; if 1 or 2 responses are observed, 14 more patients will be enrolled (7L+7H) in the second step of the trial. At the end of the second step, if 3 or less responses are observed, the trial will be considered as negative; if 4 or more responses are seen, we will conclude that the CTC FISH test is relevant to select patient for T-DM1 treatment, in either the L or/and H population, according to the observed pattern of responses. Based on the above-mentioned hypotheses and number of patients, the alpha risk was simulated to be of 6%, with a power of 94%.

Present accrual and target accrual: trial will start in summer 2013 in France. Up to 28 patients will be treated in this study.

Contact information: Francois-Clement Bidard, Institut Curie, Paris, France.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT1-1-10.

Abstract P2-11-16: Prospective comparison of prognostic factors in patients starting a third line of chemotherapy for metastatic breast cancer: An ancillary study to the CirCe01 trial

Background: Several prognostic factors and composite scores based on either patients general condition and/or usual blood analyses have been described in the setting of advanced metastatic cancers to estimate patients overall survival (OS). Over the past decade, circulating tumor cells (CTC) have been repeatedly reported as being a strong prognostic tool in metastatic breast cancer patients. We took the opportunity of the observational part of a prospective clinical trial (CirCe01, NCT01349842) that included 3rd line metastatic breast cancer patients to assess and compare several prognostic factors/scores and circulating tumor cell count.

Patients and Methods: Metastatic breast cancer patients were included before the start of a 3rd line chemotherapy at the Institut Curie, Paris, France. The following adverse prognostic factors were assessed prospectively and compared to overall survival: altered performance status (PS≥2), lymphopenia (&lt;1,000 lymphocyte/microl), elevated CTC count (CellSearch, ≥5CTC/7.5ml), low albumin (&lt;35g/l), elevated CA 15.3 (&gt;30UI/ml), elevated CEA (&gt;5ng/ml), elevated LDH (&gt;50UI/l). Two composite scores were also evaluated: the Barbot score (combining Karnofsky index, number of metastases, albumin and LDH; Barbot JCO 2008) and the Prognostic Inflammatory and Nutritional Index (PINI; combining albumin, prealbumin, orosomucoid and C-reactive protein). Metastatic sites (liver, lung, bone) were also analyzed. Survival was analyzed by Kaplan-Meier curves; multivariate analysis was done using a Cox model.

Results: 56 patients have included prospectively and 36 of them (64%) died. CA 15.3 and CEA levels, lymphopenia and metastatic sites had no significant impact on OS in univariate analysis. The incidence of the significant prognostic markers (%), their correlations (p value) and impact (p value) on overall survival are shown.

Correlation and impact on overall survival of prognostic markersFactorIncidenceCorrel. with PS (p value)Correl. with Alb (p value)Correl. with LDH (p value)Correl. with Barbot (p value)Correl. with PINI (p value)Univ. OS (p value)CTC &gt; = 545%NSNS&lt;0.001NSNS0.004PS &gt; = 214%-0.0020.04&lt;0.0010.003&lt;0.001Alb &lt;3516%--NS&lt;0.001&lt;0.001&lt;0.001LDH&gt;50065%---0.05NS0.032Barbot score &gt;316%----0.005&lt;0.001PINI &gt;1013%-----&lt;0.001

In multivariable analysis, the three independent prognostic markers on OS were: elevated CTC count (p = 0.003, HR = 3.4 95% CI [1.5-7.7]), poor PS (p = 0.005, HR = 4.1 95% IC[1.5-11.3]) and low albumin (p&lt;0.0001, HR = 11.3 95% IC[3.9-32.5]).

Discussion: CTC are an independent prognostic marker, even in advanced metastatic breast cancer. The disease aggressiveness being captured by the CTC count, usual clinical and biochemical tests appear to be sufficient to evaluate the patient prognosis, whereas more complex score (PINI, Barbot) appear to be of low interest.

Financed by: Ligue contre le cancer and PHRC 2009.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-11-16.

Abstract S6-07: Genomic characterisation of metastatic samples from breast cancer patients using next generation sequencing

Background: Although several studies have reported genomic characterisation of primary breast tumors, little is known about the genomic alterations of the metastatic tissues. Breast cancer patients who were prospectively enrolled in a trial (SAFIR01) underwent a biopsy of metastasis. The primary aim of this biopsy was to drive the treatment according to the results of whole genome CGH arrays and sanger sequencing on two genes (PIK3CA and AKT1). The results of the clinical trial were previously reported (André et al ASCO 2013). The secondary goal of the biopsies was to perform genomic characterisation of metastases in breast cancer patients. Here we report the analyses of such metastatic samples using next generation sequencing (NGS) approaches.

Patients and methods: Two approaches were applied. In order to describe the incidence of targetable genomic alterations, we performed in depth targeted sequencing on 100 genes (200x coverage) using Illumina HiSeq 2000 (DNA vision). This analysis was performed on 240 metastatic samples. The second approach was more exploratory and aimed at discovering new genes involved in the metastatic process and/or resistance to therapies. In order to achieve this goal, we performed whole exome sequencing in 100 pairs of metastatic tissue (100x) and normal DNA (Integragen Inc, Hiseq platform). Finally, phosphor-S6K staining was performed in 300 samples in order to explore the activation status of mTOR pathway in metastatic disease, and to correlate with genomic data.

Results: Targeted sequencing was performed on 240 metastatic samples in order to report the prevalence of targetable genomic alterations in metastatic breast cancer. Results are available for the first 159 samples. In addition to the already reported PIK3CA (26%) and AKT1 mutations (4%), NGS identified mutations of PTEN (4%), ERBB2 (2%), K-Ras (1%), ATM (2%), CDH1 (2%), GATA3 (2%), PTPN11 (1%), PTPRD (1%), ROS1 (1%). Results on the 81 samples, together with whole exome sequencing (n = 100) and phosphoproteins are being analysed and results will be available mid-november 2013.

Conclusion: This is the first large study that aims at defining the genomic landscape of metastatic samples. Results will provide insights into the prevalence of targetable genomic alterations in metastatic tissue, together with candidate genes involved in the metastatic process and resistance to therapies.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr S6-07.

Phase I study of humanized monoclonal antibody AVE1642 directed against the type 1 insulin-like growth factor receptor (IGF-1R), administered in combination with anticancer therapies to patients with advanced solid tumors

BACKGROUND

Type 1 insulin-like growth factor receptor (IGF-1R) mediates resistance to chemotherapy and targeted agents. This study assessed the safety, pharmacokinetics (PK), and tolerability of humanized IGF-1R antibody AVE1642 with other cancer treatments.

PATIENTS

Patients with advanced solid tumors received three weekly AVE1642 dosed at 6 mg/kg, chosen following previous study, with 75 (cohort A) or 100 mg/m(2) (B) docetaxel, 1250 mg/m(2) gemcitabine/100 mg erlotinib (C1), or 60 mg/m(2) doxorubicin (D1). Blood samples were assayed for PK, IGFs, and IGF-BP3.

RESULTS

Fifty-eight patients received 317 AVE1642 infusions. The commonest adverse events were diarrhea (37/58 patients), asthenia (34/58), nausea (30/58), and stomatitis (21/58). Dose-limiting toxic effects in cohorts C1 (diarrhea) and D1 (neutropenia) prompted addition of cohorts C2 (1000 mg/m(2) gemcitabine/75 mg erlotinib) and D2 (50 mg/m(2) doxorubicin). Grade 3-4 hyperglycemia (three cases) accompanied steroid premedication for docetaxel administration. No PK interactions were detected. There were three partial responses in cohorts B (melanoma) and C (leiomyosarcoma, two cases) and 22 stabilizations ≥12 weeks, giving a control rate of 25/57 (44%). On treatment IGF-II rose by 68 ± 25 ng/ml in patients discontinuing treatment <12 weeks, and fell by 55.5 ± 21 ng/ml with disease control (P < 0.001).

CONCLUSION

AVE1642 was tolerable with 75-100 mg/m(2) docetaxel and 1000 mg/m(2) gemcitabine/75 mg erlotinib, achieving durable disease control in 44%, with an association between IGF-II and response.

Abstract P2-01-13: Prognostic value of Circulating Tumor Cells count at progressive disease after first line chemotherapy metastatic breast patients in a large prospective multicenter trial including serum tumor markers (IC 2006–04 study)

Background: The IC 2006–04 study included prospectively 267 metastatic breast cancer patients before the start of first line chemotherapy. We previously reported and confirmed the prognostic and predictive of CTC counts before the start of treatment and after 3–4 & 6–9 weeks of treatment (Pierga, JY SABCS 2010, Ann Oncol 2012). We report here the results of the last CTC count performed at tumor progression (i.e. end of first line chemotherapy).

Methods: Patients were included in the study from 06/07 to 9/09. CTC were counted by the CellSearch® system at tumor progression (clinical and/or radiological progression).

Results: 211 patients experienced a tumor progression at time of final data analysis and the planned CTC count has been performed in 61 patients. High CTC count (≥5 CTC/7.5ml) at progression was observed in 22 patients (36%) and was associated with elevated Cyfra 21–1 and ALP and was not associated with elevated CEA, CA 15–3, LDH, the elapsed progression-free survival, the onset of new metastasis. No CTC was detected at tumor progression in the 5 patients with HER2+ disease, in line with our previous results. The prognostic markers for overall survival at tumor progression were high CTC count (median overall survival 8 vs 19 months, p = .0006) and elevated Cyfra 21–1 (p = .001). Other serum markers (CEA, CA15-3, ALP, LDH) and tumor subtypes had no prognostic value at univariate analysis. At multivariate analysis, the two prognostic factors for overall survival were high CTC count (RR = 2.3 p = 0.03) and elevated Cyfra 21–1 (RR = 3.6 p = 0.02).

Conclusion: In the prospective IC 2006–04 study, among the different markers tested at tumor progression during the first line chemotherapy for metastatic breast cancer, high CTC count and elevated Cyfra 21–1 levels were the only two independent prognostic markers for overall survival.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-01-13.

P4-07-04: Nomogram Including Circulating Tumor Cells (CTC) Count before and during Chemotherapy for Individual Survival Prediction of Metastatic Breast Cancer Patients

Background

CTC count before a new line of treatment and CTC count early changes under chemotherapy have been reported as an independent prognostic marker in metastatic breast cancer in a recent pooled analysis in 841 pts (Liu M. ASCO 2011). The aim of this study was to build a prognostic tool including CTC and other parameters to assesse its predictive value for progression-free survival (PFS) and overall survival (OS).

Methods: Data from the IC 2006–04 study were used. This prospective multicentre study included 267 metastatic breast cancer patients treated by first line chemotherapy with or without targeted therapy, in whom appropriate pre-treatment prognostic variables (age, performance status, number of metastatic sites, disease-free interval, ER, PR and HER2 status, tumor grade, LDH, serum markers, CTC count by CellSearch technique before treatment and before cycle 2) were available for statistical analysis. We constructed a multivariate Cox regression model for PFS and OS prediction. A stepwise selection process was applied to achieve the most informative and parsimonious models. Performance was measured with the C-index statistic. Internal validation was performed using leave-two-out technique.

Results: Four nomograms have been obtained, in two clinical settings: at inclusion (before the start of any treatment) taking into account the initial CTC count, and during treatment (before cycle 2) taking into account CTC changes under treatment. Their accuracy was good for PFS and OS prediction, with C-index ranging from 0.72 to 0.88. Internal validations allow considering a good accuracy of the models in an external population.

Conclusion: These clinically relevant nomograms are a simple tool for a personalized prognostic assessment including CTC assessment. Validation on independent series of patients are ongoing.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-07-04.

OT3-01-11: A Randomized, Phase II Multicenter, Double-Blind, Placebo-Controlled Trial Evaluating MetMAb and/or Bevacizumab in Combination with Weekly Paclitaxel in Patients with Metastatic Triple-Negative Breast Cancer

Background

Dysregulation of the HGF/Met pathway has been associated with tumorigenesis in many malignancies, including the basal sub-type of triple-negative breast cancer. MetMAb (RG3638) is a recombinant, humanized, monovalent monoclonal antibody directed against Met. By binding to the extracellular domain of Met, MetMAb selectively blocks ligand binding and subsequent activation by HGF. Pre-clinical data support the efficacy of combining MetMAb with numerous chemotherapy agents and with targeted agents including bevacizumab and erlotinib. In clinic, MetMAb has been generally well tolerated as a single agent (Phase I), in combination with bevacizumab (Phase Ib) and with bevacizumab in a dose escalation/expansion study (Phase Ib)1 as well as in combination with erlotinib in patients with previously treated NSCLC2. The combination of MetMAb + erlotinib in NSCLC demonstrated significant benefit in both PFS and OS in patients with Met diagnostic positive tumors whereas those patients with Met diagnostic negative tumors demonstrated a detrimental effect in both PFS and OS. The most commonly reported adverse events associated with MetMAb are peripheral edema and fatigue.

Methods: This clinical trial is a randomized three-arm Phase II study in patients with triple-negative metastatic breast cancer, which makes up the majority of basal sub-type breast cancer. Patients will be randomized (1:1:1) to either paclitaxel + bevacizumab + placebo; paclitaxel + placebo + MetMAb; or paclitaxel + bevacizumab + MetMAb. The primary endpoint of this study is PFS in all patients and by Met diagnostic status. Secondary endpoints include an evaluation of OS, ORR, safety, and pharmacokinetics. To date, 11 patients have been enrolled, and 10 patients have been treated.

Primary and secondary analyses will include all randomized patients, with patients analyzed according to the treatment arm to which they were assigned. Kaplan-Meier methodology will be used to estimate the median PFS for each treatment arm. An estimate of the HR with 95% CI will be determined using a Cox regression model with an indicator variable for the MetMAb-containing arm. Safety will be assessed through summaries of adverse events and will include all patients who receive any amount of study treatment.

This study remains open for accrual; further details on the trial can be found on the ClinicalTrials.gov website under NCT01186991.

1. Moss et al, In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2–6; Orlando, FL; AACR 2011 (abstr 4717).

2. Spigel et al, J Clin Oncol 29:2011 (suppl; abstr 7505).

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr OT3-01-11.

Low immunogenicity of seasonal trivalent influenza vaccine among patients receiving docetaxel for a solid tumour: results of a prospective pilot study

BACKGROUND

Patients receiving cytotoxic therapy for solid tumours are at risk of severe influenza. However, few data are available regarding the immunogenical efficacy of influenza vaccine in these patients.

METHODS

In this prospective study, 25 patients with breast (n=13) or prostate (n=12) cancer received a trivalent inactivated influenza vaccine along with docetaxel (Taxotere) administration. The influenza virus type A and B antibody titres were measured using haemagglutinin inhibition (Garten et al, 2009) before and 21 days after the vaccination. Seroconversion rate was defined as the percentage of patients with an increase in the serum titres ≥ 4 after vaccination.

RESULTS

Median age was 65 years (range: 33-87 years); 52% were females. Seroconversion rates were low: 28% (95% CI: 23.1-33.3) for H1N1, 8% (95% CI: 7.7-8.3) for H3N2 and 16% (95% CI: 7.7-25) for the B strain. The geometric mean titres ratios were 2.16 (H1N1), 1.3 (H3N2) and 1.58 (B). No serious adverse event (AE) related to the vaccine was reported. All the reported AE were from mild-to-moderate intensity.

CONCLUSION

In the patients receiving docetaxel for solid tumours, influenza vaccine triggers an immune response in only one third. Strategies using more immunogenic influenza vaccines must be evaluated in such patients.