Abstract PD1-02: Withdrawn

This abstract was withdrawn by the authors.

Citation Format: Cortes J, Martin M, Pernas S, Gomez Pardo P, Lopez-Tarruella S, Gil-Martin M, Manso L, Ciruelos E, Perez-Fidalgo JA, Hernando C, Ademuyiwa FO, Weilbaecher K, Mayer I, Pluard TJ, Martinez Garcia M, Vahdat L, Wach A, Barker D, Romagnoli B, Kaufman PA. Withdrawn [abstract].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 PD1-02.

Abstract P5-11-04: Anti-proliferative effect of oral metronomic vinorelbine (mVNB) in PAM50 Luminal/HER2-negative early breast cancer (SOLTI-1501 VENTANA): A randomized, three-arm, window-of-opportunity study

BACKGROUND: The anti-proliferative effect of mVNB alone or in combination with endocrine therapy in patients with hormone receptor-positive/HER2- breast cancer (BC) has been scarcely addressed.

METHODS: Postmenopausal women with untreated stage I-III BC were randomized (1:1:1) to receive 3 weeks of letrozole (LTZ) 2.5mg/day, oral mVNB 50mg 3 days/week or the combination. The 1ary objective was to evaluate, within PAM50 Luminal A/B disease, if the anti-proliferative effect of mVNB+LTZ was superior to monotherapy. An anti-proliferative effect was defined as the mean relative decrease of the PAM50 11-gene Proliferation Score in each arm. 2ary objectives included safety and the comparison of the anti-proliferative effect between arms. An unplanned analysis of stromal tumor infiltrating lymphocytes (sTILs) was performed. PAM50 analyses were performed using the nCounter®-based Breast Cancer 360TM panel. Changes in the expression of 790 genes/signatures tracking multiple biological processes from tumor cells and the microenvironment were evaluated within each arm using paired (surgery vs. baseline) univariate analyses. P-values were corrected for multiple comparisons using false discovery rate (FDR).

RESULTS: A total of 61 patients were randomized and 54 paired samples (89%) were analyzed. Main patient characteristics were mean age 67, mean tumor size 1.7 cm, stage I (55.7%) and grade 1-2 (90%). Grade 3 toxicities occurred in 3.3% of cases. Baseline samples were Luminal A (72.3%) or B (27.7%). The anti-proliferative effect of mVNB+LTZ (-73.2%) was superior to both monotherapy arms combined (-49.9%; p=0.001) and mVNB (-19.1%; p<0.001). The anti-proliferative effect of mVNB+LTZ (-73.2%) was higher compared to LTZ (-65.7%) but did not reach statistical significance (p=0.328). Across the mVNB+LTZ, LTZ and VNB arms, 413 (52.3%), 403 (51.0%) and 21 (2.6%) genes/signatures were found differentially expressed (FDR<5%) between baseline and surgery samples. Compared to mVNB+LTZ baseline samples, surgical samples showed higher expression of AP-1 transcription factor subunits FOS and JUN, inflammatory chemokines (e.g. CCL4 and IL6), stromal-related genes (e.g. CAV1 and stroma signature) and immune infiltration (e.g. CD8 T-cell signature) and lower expression of proliferation-related genes (e.g. MKI67 and UBE2C), estrogen receptor-signaling and Risk of Recurrence. Of the 413 genes found differentially expressed in surgical samples compared to baseline samples in the mVNB+LTZ arm, 108 (26.2%) were not found in the LTZ arm. Among them, high expression of LAG3, CD24, CD84 and CCR5. Under the microscope, sTILs (≥10% at week 3) were observed in 6.6% (mVNB), 15% (LTZ) and 26% (mVNB+LTZ) of the cases. In tumors with ≤10% TILs at baseline, an increase in TILs was observed following LTZ (p=0.049) and mVNB+LTZ (p=0.012).

CONCLUSIONS: mVNB is well-tolerated and presents antiproliferative activity alone and in combination with LTZ. The increase of activated CD8 T-cells or TILs observed with LTZ+mVNB opens the possibility of studying combinations with immunotherapy. Further investigation comparing these biological results with other metronomic schedules or combinations is warranted.

Citation Format: Prat A, Adamo B, Pascual T, Perez Fidalgo JA, Blanch S, Martínez N, Gomez Pardo P, Lopez Gonzalez A, Murillo Jaso L, Amillano K, Vidal M, Paré L, Canes J, Galvan P, Gonzalez Farre B, Ortega Cebrián V, Gonzalez X, Bellet Ezquerra M, Villagrasa P, Ciruelos E. Anti-proliferative effect of oral metronomic vinorelbine (mVNB) in PAM50 Luminal/HER2-negative early breast cancer (SOLTI-1501 VENTANA): A randomized, three-arm, window-of-opportunity study [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 P5-11-04.

Abstract OT1-01-04: VENTANA (SOLTI-1501): Oral metronomic vinorelbine combined with endocrine therapy in luminal/HER2-negative early breast cancer: A window of opportunity trial

BACKGROUND

The CDK4/6 inhibitor palbociclib, in combination with endocrine therapy (ET), has been approved for patients (pts) with HR+/HER2- metastatic breast cancer (BC), suggesting that inhibition of the cell cycle in combination with ET is a strategy to keep exploring. In this context, vinorelbine (VNB) inhibits chromosome segregation during mitosis and blocks cells at G2/M. Interestingly, several metronomic schedules of VNB are being used in the clinical setting, a strategy that might not only affect cell-cycle but also aims to target tumor angiogenesis.

VENTANA is a “window-of-opportunity” trial designed to explore whether, similarly to CDK4/6 and mTOR inhibitors, oral metronomic VNB in combination with endocrine therapy induces a superior anti-proliferative effect than ET alone, as suggested by preclinical and clinical studies. We believe that a biological synergy of the combined treatment could open the door to include this treatment strategy in pts with BC as an alternative to CDK4/6 inhibitors.

METHODS

VENTANA is a phase 0 multicenter, three-arm, randomized clinical trial of oral metronomic VNB and letrozole (LET) versus either treatment alone in postmenopausal women with newly diagnosed, untreated HR+ and HER2-, stage I-III operable BC. Other eligibility criteria include primary tumor size ≥1 cm (cT1-3) and N0-1, ECOG PS 0-1 and evaluable diagnostic tumor sample. Pts are randomized (1:1:1) to receive LET 2.5mg daily, oral VNB 50mg 3 days a week, or LET 2.5mg daily and oral VNB 50mg 3 times a week. After 3 weeks of treatment, pts will undergo surgery, and both pre-treatment and post-treatment surgical samples will be analyzed for gene expression. Primary objective is to test if oral metronomic VNB and LET induce a superior anti-proliferative effect than either drug alone in pts with early BC defined as Luminal by PAM50. This will be evaluated by the expression of 11 proliferative genes contained in the PAM50 subtype predictor (BIRC5, CCNB1, CDC20, CDCA1, CEP55, KNTC2, MKI67, PTTG1, RRM2, TYMS and UBE2C) as surrogate signature biomarker of its anticancer activity.

VENTANA is a proof-of-concept study to describe the change in the expression of a proliferation-related gene signature in all 3 treatment arms. Changes in the proliferation signature will be determined by following formula: Mean suppression of proliferation signature score = 100 − [geometric mean (post treatment proliferation score / pre-treatment proliferation score · 100)]. By evaluating other BC-related gene signatures (560 genes), the antiangiogenic and immunogenic potential of the treatment arms will also be compared and genes regulated in a treatment-specific manner identified. All analyses will be performed within the different PAM50-defined subtypes (Luminal, Luminal A or Luminal B).

As the primary endpoint is continuous and there are no previous data to make assumptions about the degree of suppression of these genes, the sample size has not been determined by statistical calculations. A sample size of 20 pts per arm is considered appropriate to support our hypothesis. The targeted accrual of 60 pts will be enrolled in 10 sites across Spain (EudraCT Number 2015-004714-24).

Citation Format: Adamo B, Vidal M, Gomez Pardo P, Zaragoza K, Ciruelos E, Virizuela JA, Blanch Tormo S, Pérez-Fidalgo JA, Murillo L, Lopez-Gonzalez A, Amillano Parraga K, Martinez Jañez N, Gonzàlez Farré X, Prat A. VENTANA (SOLTI-1501): Oral metronomic vinorelbine combined with endocrine therapy in luminal/HER2-negative early breast cancer: A window of opportunity trial [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 OT1-01-04.

Abstract P4-03-04: Body Mass Index as a Predictive Factor of Pathological Complete Response to Neoadjuvant Chemotherapy in Breast Cancer Patients

Background: Obesity has been associated with worse pathological complete response (pCR) to neoadjuvant chemotherapy (NACT) and overall outcome in breast cancer patients (pts). Our aim was to retrospectively evaluate body mass index (BMI) as a predictive factor of pCR to NACT in pts treated at our institution, taking into account tumor HER2 status and CT dose adjustment.

Pts and methods: Pts with invasive breast cancer who received NACT followed by surgery at Vall d'Hebron University Hospital from January 2004 to December 2008 were analyzed. Pts were categorized as normal/underweight (BMI < 25 kg/m2), overweight (BMI of 25 to < 30 kg/m2), and obese (BMI ≥30 kg/m2). The overweight and obese groups were combined (BMI-high) and then compared with the normal/underweight group. Univariate and multivariate analyses were performed to assess the association between BMI and pCR (no invasive tumor in breast and nodes).

Results: 256 consecutive pts were included. Median age was 52.5 years. According to BMI, 38.7% were normal/underweight and 59.4% were BMI-high. 23.4% of the pts had HER2 positive tumors (n=60), 84% received anthracyclines-and taxanes-based CT, and 46.6% of the HER2 positive pts were treated with trastuzumab. Drug dose was reduced in only five pts with a body surface area > 2m2. No statistically significant association was found between BMI and any tumor characteristics. In the univariate analysis, BMI-high was associated with worse pCR in the whole population (p=0.017), as well as in HER2 positive pts (p=0.013). In the multivariate analysis, BMI did not significantly predict pCR in the total population, although a trend was observed (p=0.098). In the HER2 positive subgroup, however, BMI was an independent predictive factor of pCR (p=0.001). Among luminal A [estrogen receptor positive and/or progesterone receptor positive and (Ki67 < 20% and histological grade 1 or 2)], luminal B [estrogen receptor positive and/or progesterone receptor positive and (Ki67 ≥20% or histological grade 3)], and triple negative tumors, BMI was not a predictive factor of pCR.

Conclusions: Our results suggest that higher BMI is likely associated with worse pCR, particularly in HER2 positive pts. A better understanding of the molecular links between obesity and breast cancer is necessary to identify new predictive factors of pCR to NACT.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-03-04.