Tumor-infiltrating lymphocytes and molecular response after neoadjuvant therapy for HR+/HER2- breast cancer: results from two prospective trials

PURPOSE

The aim was to evaluate the role of tumor-infiltrating lymphocytes (TIL) in predicting molecular response after preoperative endocrine or cytotoxic treatment for HR+/HER2- patients who do not achieve a pathological complete response.

METHODS

Stromal (Str) TIL were centrally evaluated on samples from diagnostic core-biopsies of HR+/HER2- patients included in two prospective randomized trials: the LETLOB trial (neoadjuvant endocrine-based treatment) and the GIOB trial (neoadjuvant chemotherapy-based treatment). Pre- and post-treatment Ki67 was centrally assessed.

RESULTS

StrTIL were evaluable in 111 cases (n = 73 from the LETLOB trial and n = 38 from the GIOB trial). Median StrTIL was 2%. Patients with high StrTIL (StrTIL ≥10%, n = 28) had more frequently breast cancer of ductal histology (p = 0.02), high grade (p = 0.049), and high Ki67 (p = 0.02). After neoadjuvant endocrine treatment (LETLOB cohort), a significant Ki67 suppression (p < 0.01) from pre- to post-treatment was observed in both the low and high StrTIL groups. High StrTIL patients achieve more frequently a relative Ki67 suppression ≥50% from baseline as compared to low StrTIL patients (55 vs. 35%, p non significant). After neoadjuvant chemotherapy (GIOB cohort), a significant Ki67 suppression was observed only for low StrTIL patients (Wilcoxon p = 0.001) and not in the high StrTIL group (p = 0.612). In this cohort, the rate of patients achieving a relative Ki67 suppression ≥50% from baseline was significantly higher in the low vs high StrTIL group (64% vs 10%, p = 0.003). Geometric mean Ki67 suppression was evaluated in each cohort according to StrTIL: the lowest value (-41%) was observed for high StrTIL cases treated with chemotherapy.

CONCLUSIONS

This hypothesis-generating study suggests that in HR+/HER2- breast cancer StrTIL at baseline may influence the achievement of a molecular response after neoadjuvant treatment. Further evaluation in large studies is needed, and interaction with the type of treatment warrants to be explored.

Abstract P1-09-12: Dose dense adjuvant chemotherapy in patients with early breast cancer: Differential treatment effects according to composite index of benefit

Background In patients with node-positive early breast cancer (EBC), dose-dense adjuvant chemotherapy improves disease-free survival (DFS) compared with standard interval chemotherapy. The GIM2 trial supports the value of dose-dense chemotherapy and suggests that the benefit is present in patients with hormone receptor-negative or hormone receptor-positive tumours (Del Mastro et al. Lancet 2015). In order to individualize decision making, there is a need to examine the absolute treatment effects of dose dense chemotherapy according to patient and tumor characteristics.

Patients and Methods The randomized phase III GIM2 trial enrolled 2091 patients. The primary endpoint was DFS. A continuous, composite measure of treatment benefit for each patient was determined from a Cox model incorporating potential predictive factors (age: 25-40/41-55/56-71; histological grade: 1+2/3; hormonal receptor status: positive/negative). Subpopulation treatment effect pattern plot methodology was used to reveal differential treatment effects on DFS according to composite index. The study focused on patients with HER2–negative disease (N=1287).

Results On average, the magnitude of benefit with dose dense chemotherapy versus standard chemotherapy ranged widely across different subpopulations, as quantified by the composite measure of relevant variables. The highest benefit was observed in patients with high grade, hormone receptor-negative disease (hazard ratio for DFS 0.44, 95% CI 0.23-0.83). Of note, a relevant benefit was observed also in patients with high grade, hormone receptor-positive disease (hazard ratio for DFS 0.74, 95% CI 0.50-1.09).

Conclusion The absolute improvement in DFS with dose dense adjuvant chemotherapy is substantial in some patients with node-positive HER2-negative breast cancer, particularly those regarded as having high index risk (hormone receptor-negative, high grade disease). Interestingly, a significant effect of dose dense chemotherapy was observed also in patients with hormone receptor-positive, high grade disease.

Citation Format: Puglisi F, Ceppi M, Cognetti F, De Placido S, Bruzzi P, De Laurentiis M, Bisagni G, Cavazzini G, Durando A, Turletti A, Valle E, Montemurro F, Barni S, Ardizzoni A, Gamucci T, Colantuoni G, Del Mastro L. Dose dense adjuvant chemotherapy in patients with early breast cancer: Differential treatment effects according to composite index of benefit [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 P1-09-12.

Abstract P4-21-04: Preliminary safety and efficacy of first-line pertuzumab combined with trastuzumab and taxane therapy for HER2-positive locally recurrent/metastatic breast cancer (PERUSE)

Background: First-line (1L) docetaxel+trastuzumab+pertuzumab (THP) for HER2-positive metastatic breast cancer (MBC) significantly improved progression-free survival (PFS) and overall survival in the phase III CLEOPATRA trial, and led to the approval of this regimen. PERUSE (NCT01572038) was designed to assess the safety and efficacy of investigator's choice of taxane+HP for 1L locally recurrent (LR)/MBC, and allows exploration of safety and efficacy in a larger population.

Methods:

PERUSE is a multicenter, single-arm phase IIIb study. Patients (pts) with Eastern Cooperative Oncology Group performance status ≤2 and no prior systemic therapy for LR/MBC (except endocrine therapy) receive T, paclitaxel (PAC), or nab-PAC plus H (8 mg/kg→6 mg/kg every 3 weeks [q3w]) and P (840 mg→420 mg q3w) until disease progression (PD) or unacceptable toxicity. The primary endpoint is safety. Secondary endpoints include best overall response (BOR) and PFS.

Results:

The safety/ITT population includes 1436 pts at data cutoff (1 Apr 2016). Median follow-up was 17.2 mo (range, &lt;1–41.4). The median pt age was 54 years (range 23–87), 64% had hormone receptor-positive disease, 27% received adjuvant H, and 75% had visceral disease. Pts received T, PAC, nab-PAC, H, and P for a median of 3.8 mo (range &lt;1–24.2; n=791), 4.2 mo (&lt;1–36.6; n=618), 3.9 mo (&lt;1–17.3; n=73), 16.0 mo (&lt;1–45.9; n=1435), and 16.1 mo (&lt;1–45.9; n=1436), respectively.

Most pts discontinued taxanes for 'other' reasons (25%), adverse events (AEs; 16%), PD, or investigator decision (15% each); H, for PD or AEs (46% and 7%); and P, for PD or AEs (46% and 8%).

Grade ≥3 treatment-emergent AEs (TEAEs) of interest are shown in table 1. Serious TEAEs were reported in 282 (36%) pts on T, 185 (31%) on PAC, and 21 (32%) on nab-PAC. Preliminary efficacy by taxane is shown in table 2.

Table 1Pts, n (%)TPACNab-PAC n=775n=589n=65Neutropenia110 (14)31 (5)1 (2)Diarrhea62 (8)50 (8)4 (6)Febrile neutropenia81 (10)7 (1)0Fatigue21 (3)10 (2)1 (2)Asthenia16 (2)10 (2)0Peripheral neuropathy10 (1)15 (3)0Anemia11 (1)12 (2)2 (3)Left ventricular dysfunction1 (&lt;1)9 (2)1 (2)

Table 2 TPACNab-PACBOR, based on pts with measureable disease at baseline, n (%)n=659n=482n=53Complete72 (11)80 (17)4 (8)Partial442 (67)319 (66)38 (72)Stable disease112 (17)62 (13)8 (15)PD18 (3)12 (2)2 (4)Missing15 (2)9 (2)1 (2)PFS, ITT populationn=775n=589n=65Pts with events, n (%)439 (57)324 (55)40 (62)Median, mo (95% confidence interval)19.6 (17.4–22.6)24.8 (20.7–27.0)18.1 (11.9–34.2)25th–75th percentile, mo9.4–not reached (NR)10.2–NR7.9–NR

Conclusion:

The preliminary findings of this large, single-arm study suggest that safety and efficacy of 1L taxane+HP for HER2-positive LR/MBC are in keeping with the results of the phase III CLEOPATRA study. There was less febrile neutropenia with PAC/nab-PAC+HP compared with THP, and preliminary PFS was similar to that seen in the CLEOPATRA study for all taxane+HP combinations.

Citation Format: Bachelot T, Puglisi F, Ciruelos E, Peretz-Yablonski T, Schneeweiss A, Easton V, Lindegger N, Restuccia E, Miles D. Preliminary safety and efficacy of first-line pertuzumab combined with trastuzumab and taxane therapy for HER2-positive locally recurrent/metastatic breast cancer (PERUSE) [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 P4-21-04.

Abstract OT1-01-05: PAINTER: Evaluation of eribulin tolerability and correlation between a set of polymorphisms and neuropathy in patients with metastatic breast cancer

BACKGROUND Eribulin is a synthetic analogue of halichondrin B which inhibits microtubule dynamics. It has been approved in Europe for the treatment of locally advanced or metastatic breast cancer (mBC) progressed after at least two chemotherapy regimens for advanced disease. The most common adverse events (AEs) were fatigue, neutropenia and peripheral neuropathy, which occurs with an incidence ranging from 13.9% to 35%. It was severe only in a small proportion of patients, suggesting an individual susceptibility. The neurotoxicity mechanisms associated with microtubulin interfering agents have not been fully defined. Few studies reported an association between some SNPs (Single Nucleotide Polymorphisms) and microtubulin interfering agents-induced neuropathy, mainly taxanes. As the use of Eribulin becomes more widespread, a better knowledge of its safety profile, outside of clinical trials, is warranted. Given that Eribulin toxicity can result in treatment discontinuation, the ability to anticipate which patients will experience severe toxicity could allow for either early intervention or even possibly for prophylactic therapy, or for a better selection of patients eligible for treatment.

METHODS This is a multicenter, interventional, single-arm, phase IV study. The primary objective is the evaluation of the safety and tolerability profile of Eribulin in an unselected population of patients with mBC. Secondary objectives are the description of compliance to treatment and efficacy.

ENDPOINTS

•Incidence, time of onset, severity and duration of all AEs experienced during treatment with Eribulin, especially the most common reported in previous studies but also other possible unexpected toxicities.

•Association between a set of selected SNPs and the onset of any grade peripheral neuropathy. Specifically, 15 SNPs located in genes involved in microtubule dynamics or resulted from genome wide association studies, will be analyzed.

•Evaluation of quality of life during treatment using validated questionnaires.

•Assessment of dose intensity and dose schedule maintenance.

•DOT (Duration Of Treatment) and OS (Overall Survival).

STATISTICAL METHODS Summary statistics will be used in order to describe patient characteristics. Safety endpoints will be estimated by means of absolute and relative frequencies and associated 95%CI. The relationship between baseline variables and the risk of severe toxicity, as well as the relationship between SNPs and risk of neuropathy will be described by means of contingency tables and their association with outcome will be assessed by χ2 test of Mantel-Haenzel and a logistic regression model. DOT and OS will be described using Kaplan-Meier curves. A sample size of 200 patients will also allow us to get a good fitting for statistical analysis of the relationship between primary endpoint and not more than 10 factors. Regarding the relationship between SNPs and risk of neuropathy it will be feasible to screen for association about 10-15 SNPs, with known prevalence &gt;15%.

PRESENT ACCRUAL AND TARGET ACCRUAL 98 of 200 patients were enrolled until 18/05/2016. Target accrual is open for 200 patients.

CONTACT INFORMATION Nicla La Verde: nicla.laverde@asst-fbf-sacco.it.

Citation Format: La Verde N, Moretti A, Damia G, Paternò E, Santini D, Garrone O, Fabi A, Ciccarese M, Cretella E, Torri V, Generali D, Grasso D, Puglisi F, Collovà E, Roila F, Bertolini A, Barni S, Vici P, Luigi C, Scandurra G, Bramati A, Dazzani MC, Farina G. PAINTER: Evaluation of eribulin tolerability and correlation between a set of polymorphisms and neuropathy in patients with 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 OT1-01-05.