Association between endocrine adjuvant therapy intake timing and disease-free survival in patients with high-risk early breast cancer: results of a sub-study of the UCBG- UNIRAD trial

BACKGROUND

Circadian rhythms regulate cellular physiology and could influence the efficacy of endocrine therapy (ET) in breast cancer (BC). We prospectively tested this hypothesis within the UNIRAD adjuvant phase III trial (NCT01805271).

METHODS

1278 patients with high-risk hormonal receptor positive (HR+)/HER2 negative (HER2-) primary BC were randomly assigned to adjuvant ET with placebo or everolimus. Patients prospectively reported in a diary the daily timing of ET intake among four 6-h slots (06:00-11:59 (morning), 12:00-17:59 (afternoon), 18:00-23:59 (evening), or 24:00-05:59 (nighttime). The association between ET timing and disease-free survival (DFS) was a prespecified secondary endpoint of the trial and the results of this observational study are reported here.

FINDINGS

ET timing was recorded by 855 patients (67.2%). Patients declaring morning (n = 465, 54.4%) or afternoon (n = 45, 5.4%) ET intake were older than those declaring evening (n = 339, 39.6%) or nighttime (n = 5, 0.6%) intake. With a median follow-up of 46.7 months, 118 patients had a local (n = 30) or metastasis relapse (n = 84), and 41 patients died. ET intake timing was not associated with DFS in the whole population (HR = 0.77, 95% CI [0.53-1.12]). The association between ET intake timing and DFS according to the stratification factors revealed interactions with ET agent (tamoxifen versus Aromatase inhibitors (AI) with an increased DFS in the group of evening/nighttime versus morning/afternoon tamoxifen intake (HR = 0.43, 95% CI [0.22-0.85]), while no association was found for AI intake (HR = 1.07, 95% CI [0.68-1.69]). The interaction between ET intake timing and ET agent remained in multivariable analysis (HR = 0.38 [0.16-0.91]).

INTERPRETATION

Tamoxifen intake in the evening/nighttime could be recommended in patients with high-risk HR+/HER2- BC while awaiting for results from further ET timing studies.

FUNDING

UNIRAD was Supported by a grant from the French Ministry of Health PHRC 2012 and received funding from La Ligue contre le Cancer, Cancer Research-UK, Myriad Genetics, and Novartis.

Tucatinib and Trastuzumab for Previously Treated Human Epidermal Growth Factor Receptor 2-Positive Metastatic Biliary Tract Cancer (SGNTUC-019): A Phase II Basket Study

PURPOSE

To evaluate the efficacy and safety of tucatinib and trastuzumab in patients with previously treated human epidermal growth factor receptor 2-positive (HER2+) metastatic biliary tract cancer (mBTC).

METHODS

SGNTUC-019 (ClinicalTrials.gov identifier: NCT04579380) is an open-label phase II basket study evaluating the efficacy and safety of tucatinib and trastuzumab in patients with HER2-altered solid tumors. In the biliary tract cancer cohort, patients had previously treated HER2 overexpressing or amplified (HER2+) tumors (identified with local testing) with no prior HER2-directed therapy. The primary end point was confirmed objective response rate (cORR) per investigator assessment. Patients were treated on a 21-day cycle with tucatinib (300 mg orally twice daily) and trastuzumab (8 mg/kg intravenously followed by 6 mg/kg every 3 weeks).

RESULTS

Thirty patients were enrolled. As of data cutoff (January 30, 2023), the median duration of follow-up was 10.8 months. The cORR was 46.7% (90% CI, 30.8 to 63.0), with a disease control rate of 76.7% (90% CI, 60.6 to 88.5). The median duration of response and progression-free survival were 6.0 months (90% CI, 5.5 to 6.9) and 5.5 months (90% CI, 3.9 to 8.1), respectively. At data cutoff, 15 patients (50.0%) had died, and the estimated 12-month overall survival rate was 53.6% (90% CI, 36.8 to 67.8). The two most common treatment-emergent adverse events (TEAEs) were pyrexia (43.3%) and diarrhea (40.0%). Grade ≥3 TEAEs were reported in 18 patients (60.0%), with the most common being cholangitis, decreased appetite, and nausea (all 10.0%), which were generally not treatment related. TEAEs led to treatment regimen discontinuation in one patient, and there were no deaths due to TEAEs.

CONCLUSION

Tucatinib combined with trastuzumab had clinically significant antitumor activity and was well tolerated in patients with previously treated HER2+ mBTC.

Paclitaxel plus carboplatin and durvalumab with or without oleclumab for women with previously untreated locally advanced or metastatic triple-negative breast cancer: the randomized SYNERGY phase I/II trial

Chemo-immunotherapy is the first-line standard of care for patients with PD-L1 positive metastatic triple-negative breast cancer (mTNBC). SYNERGY (NCT03616886) is a dose-finding phase I and a randomized phase II, open-label trial evaluating if targeting the immunosuppressive adenosine pathway can enhance the antitumor activity of chemo-immunotherapy. The phase I part included 6 patients with untreated locally-advanced or mTNBC to determine the safety and recommended phase II dose of the anti-CD73 antibody oleclumab in combination with the anti-PD-L1 durvalumab and 12 cycles of weekly carboplatin and paclitaxel. In the phase II part, 127 women were randomized 1:1 to receive chemo-immunotherapy, with (arm A) or without (arm B) oleclumab. The primary endpoint was the clinical benefit rate at week 24, defined as stable disease, partial or complete response per RECIST v1.1. Secondary endpoints included objective response rate, duration of response, survival outcomes (progression-free survival and overall survival), and safety. The trial did not meet its primary endpoint, as the 24-week clinical benefit rate was not significantly improved by adding oleclumab (43% vs. 44%, p = 0.61). Exploratory median progression-free survival was 5.9 months in arm A as compared to 7.0 months in arm B (p = 0.90). The safety profile was manageable in both arms.

Abstract P4-07-16: B-IMMUNE final analysis: a phase Ib/II study of durvalumab combined with dose-dense EC in a neoadjuvant setting for patients with locally advanced luminal B HER2(-) or triple negative breast cancers

Background: Neoadjuvant association of immune checkpoints inhibitors (ICI) and dose dense chemotherapy is promising for triple negative breast cancers (TNBC). However, response rates vary from one study to another. Timing, best chemotherapy partner and efficacy in less immunogenic breast cancer (BC), like luminal B tumors, should be further investigated. This study evaluates for TNBC and luminal B HER2(-) BC the neoadjuvant treatment with paclitaxel followed by a short combination of an anti-PD-L1 antibody with anthracyclines. Method B-IMMUNE (NCT03356860), a multicentric phase Ib/II prospective trial, included patients with stage I to III luminal B HER2(-) or TNBC treated with paclitaxel 80mg/m2 weekly from week 1 to 12 followed by 4 cycles of epirubicine 90mg/m2 and cyclophosphamide 600 mg/m2 (EC) Q2W in a neoadjuvant setting. Phase Ib evaluated a single infusion of durvalumab (anti-PD-L1) combined with the 3rd cycle of EC. Phase II evaluated infusions of durvalumab with the 1st and 3rd EC cycles. Surgery was planned 3 weeks after the last EC cycle. Primary objectives were safety and pathological complete response (pCR) rate compared to a historical control. Secondary endpoint was the overall response rate (ORR) based on breast MRI. Eleven patients were enrolled in a control arm without durvalumab, exclusively for translational research purposes. Based on a 2-stage Simon design with an α = 0.1 and β = 0.1, 22 TNBC patients were needed in the phase II to test a null hypothesis of 30% pCR rate against a one-side alternative of 60%, and 24 luminal B BC patients to test a null hypothesis of 15% pCR rate against a one-side alternative of 40% (including an additional accrual margin of 10% for eventual dropouts). At least 9 pCRs had to be observed among the first 20 evaluable TNBC patients and 6 among the first 22 evaluable luminal B patients to rule out the null hypothesis. Results This analysis concerns the 50 patients treated with the experimental treatment, 3 from the phase Ib and 47 from the phase II part. Median age was 51 y-old (31 to 72y), tumor subtypes were 24 TNBC, 25 Luminal B and one sarcoma excluded from the efficacy analysis. Seven (14%) patients had a stage I tumor, 17 (34%) a stage IIA, 13 (26%) a stage IIB, 8 (16%) a stage IIIA, 4 (8%) a stage IIIB and 1 (2%) a stage IIIC. Concerning safety, 232 AEs were reported on 39/50 patients and 34 (14,6%) were graded ≥ 3. The 5 most frequent all-grade AEs were fatigue (8,2%), diarrhea (5,6%), neutropenia (5,2%), anemia and nausea (4,3%). Most frequent grade 3 AEs were anemia and neutropenia (14,7%). Among 4 immune-related adverse events, all were thyroid disorders. One patient died 10 months after the end of treatment due to progressive disease in the liver. Forty-six of the 47 phase II patients were evaluable for efficacy. pCR was reported in 12/22 TNBC patients (55%) and 8/24 luminal B HER2(-) patients (33%). Subgroup analyses based on PD-L1 expression and TILs score are planned. Conclusions The B-IMMUNE study met its primary objective showing a significant improvement in pCR versus the historical control in both TNBC and in Luminal B HER2(-) BC cohorts with the addition of only 2 doses of durvalumab to the anthracyclines. The safety profile is comparable to those previously described with reported immune related adverse events limited to thyroid endocrine disorders.

Citation Format: Alix Devaux, Gabriela Beniuga, Claire Quaghebeur, Stéphanie Henry, Mieke Van Bockstal, Christine Galant, Paul Delrée, Jean-Luc Canon, Brigitte Honhon, Dominique Korman, Vincent Verschaeve, Christophe Lonchay, Sarah Lefevre, Lionel D’Hondt, Martine Berlière, Sophie Delmarcelle, Jean-Michel Mine, Timour Willems, Gebhard Müller, Nathalie Myant, Isabelle Bar, Sandy Haussy, Pierre G. Coulie, François P. Duhoux, Javier Carrasco. B-IMMUNE final analysis: a phase Ib/II study of durvalumab combined with dose-dense EC in a neoadjuvant setting for patients with locally advanced luminal B HER2(-) or triple negative breast cancers. [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-07-16.

Abstract P2-02-07: Patients’ selection of daily timing of oral intake of adjuvant hormonotherapy (HT) and everolimus (EVE) for high risk early breast cancer in the UCBG-UNIRAD phase III trial

Background: Everolimus (EVE) addition to adjuvant hormonotherapy (HT) for high-risk early breast cancer (BC) did not improve 3-year disease-free survival (DFS) compared with ET alone in the randomized UNIRAD trial (NCT01805271) (1). Most patients (pts) withdrew from EVE for adverse events nearly midway before the expected treatment duration of 2 years. The main EVE target involves m-TOR-induced S6 protein phosphorylation, which is controlled by the molecular circadian clock in mice and cells. Toward the analysis of possible circadian time-dependencies in EVE toxicities and efficacy, we first determine the actual distribution of the daily times chosen by the patients for both oral EVE and HT intakes.

Patients and methods: The registered pts were asked to record the clock hours they chose for both HT and EVE or placebo (PLAC) intakes within four possible daily 6-h slots, i.e. from 06:00 to 11:59 (morning), 12:00 to 17:59 (midtime), 18:00 to 23:59 (evening), or 24:00 to 05:59, (night) in a daily diary throughout their participation in the trial. Modifications in times of drugs intake were reported. Comparisons between groups involved Kruskal-Wallis sum test and Pearson’s Chi-squared and Fisher’s exact tests.

Results: Out of 1,278 randomized patients, 1063 (83,1 %) recorded the times of EVE or PLAC intakes, 852 recorded those for HT intakes. Only 10 pts reported night EVE/PLAC intakes and were not considered here. Of the 1053 evaluated pts; 549 pts took EVE/PLAC in the morning, 82 pts at midtime and 422 in the evening. As compared with evening intakes, morning or midtime intakes of EVE or PLAC were significantly associated with an older age, and post-menopausal status, whilst younger and premenopausal women preferentially chose evening intakes (p< 0.001 for both). Consistently, HT with aromatase inhibitors (AI) were mostly taken in the morning or at midtime, whereas tamoxifene (TAM) was mostly taken the evening (p = 0.001). Tumor size, lymph nodes involvement, histological grade, hormonal receptors status, and EVE initial dose were similarly distributed among the three time slots (Table 1). A similar distribution of oral intake times as in the whole timing study population was found according to age, menopausal status and HT type in the EVE arm (N=508 pts), and in the HT population (+/- EVE or PLAC) (N=852 pts). Initial oral timing intake was modified for EVE by 50 of 508 pts (10%) and for HT by 10 of 852 pts (1%).

Conclusion: To the best of our knowledge, it is the first time that the patients’ spontaneous selection of daily times for oral intakes of a targeted agent (EVE) and HT is reported in a large series of early breast cancer pts. Age and menopausal status were important determinants of patient-selected daily timing intakes of both EVE and HT, as well as HT types. These findings will be carefully considered in the analyses of possible EVE and HT timing effects on adverse events and efficacy of the current adjuvant regimens.

1) Bachelot T et al, J Clin Oncol. 2022 May 23

Abstract PD17-02: ctDNA Molecular Response based on breast cancer driver mutations predicts progression in aromatase inhibitor-sensitive first line treatment of oestrogen receptor-positive (ER+) HER2-negative (HER2-) advanced breast cancer

Background: The combination of a CDK4/6 inhibitor and an aromatase inhibitor (AI) is the gold standard for AI-sensitive first line treatment of ER+ HER2- advanced breast cancer. Nevertheless, some patients progress rapidly and may benefit from alternative strategies. Early ctDNA dynamics have been shown to predict disease course in several clinical situations. Here, we use samples from the PADA-1 trial to assess this strategy for patients receiving AI and palbociclib as first line treatment. PADA-1 was designed to assess the clinical utility of sequential analysis of ctDNA for emerging ESR1 mutations to trigger an early switch from AI plus palbociclib to fulvestrant plus palbociclib treatment. The study included 1,017 patients and was positive on its primary end-point. The objective of this translational study was to analyze the predictive value of 4-week molecular response (MR) for patient progression. Material & Method: First, a CLIA-validated targeted next-generation sequencing-based test (Guardant360 Response) was used to characterize changes in ctDNA level via detection of somatic single-nucleotide variants (SNVs), insertion/deletion mutations (indels), and gene fusions in 74 genes frequently mutated in cancer. A second analysis was restricted to cancer-associated mutations in 11 genes commonly mutated in breast cancer (PIK3CA, GATA3, TP53, AKT1, ERBB2, BRCA1, BRCA2, ATM, ESR1, PALB2 and RB1). The threshold for molecular response was defined as ≥ 50% decrease in ctDNA (MR score < 0.5). Subjects with ctDNA levels below the test’s limit of quantitation (ctDNA-low) were considered molecular responders. Results: 372 subjects with matched baseline and 4-weeks samples were available for analysis. Of these, 134 subjects (36%) were ctDNA-low, and 238 subjects (64%) quantifiable. Among the quantifiable subjects, 183 (77%) were molecular responders (MR+, MR < 0.5), and 55 (23%) were not (MR–, MR ≥ 0.5). PFS was moderately improved for both MR+ and ctDNA-low relative to MR– (HR=0.61 (95%CI 0.44-0.85), p< 0.01) over the full 29 months of follow up. Differential PFS event rate was observed only in the first 8 months following ctDNA assessment; during this time MR+ and ctDNA-low were associated with more significantly decreased risk of progression (HR 0.24, 95% CI 0.13 – 0.43, p=0.0001). Limiting ctDNA assessment to genes commonly mutated in breast cancer enhanced the predictive power of MR (HR=0.08, 95% CI 0.04 0.17, p< 0.001, for MR+ and ctDNA-low vs. MR– across 8 months post-assessment); however, fewer samples were quantifiable by this method (169 [45%] quantifiable; 203 [55%] ctDNA-low). Combining MR status with additional molecular features (e.g.tumor mutational burden and maximum mutation allele fraction) did not improve prediction of non-response. Conclusion: Changes in ctDNA fraction during the first weeks of treatment are predictive of long term clinical benefit on an individual patient basis, particularly during the first year of therapy. Adjusting the MR threshold and/or limiting to genes known to be relevant in the specific tumor can tailor the assessment of ctDNA change to specific clinical scenarios where greater sensitivity or specificity may be required. The identification of patients at high risk for early clinical failure at the onset of treatment may allow for therapy escalation and/or change to improve outcome in this population. Funding: Pfizer and Guardant Health

Citation Format: Caroline Bailleux, Thomas Bachelot, Francois-Clement Bidard, Anne-Claire Hardy-Bessard, Ivan Bièche, Anne Pradines, Florian Clatot, thibault DE LA MOTTE ROUGE, Jean-Luc Canon, Barbara Pistilli, Kyle Chang, Katie J. Quinn, Heather L. Gustafson, Florence Dalenc, Cyril Foa, Hanifa Ammarguellat, Chantal Bernard-Marty, Brigitte Lucas, Sophie Barthier, Fabrice Lorchel, Olivier Gisserot, Laurent Arnould, Marjorie Mauduit, Jérôme Lemonnier, Frédérique Berger, Suzette Delaloge, Fabrice Andre. ctDNA Molecular Response based on breast cancer driver mutations predicts progression in aromatase inhibitor-sensitive first line treatment of oestrogen receptor-positive (ER+) HER2-negative (HER2-) advanced breast cancer. [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr PD17-02.

Everolimus Added to Adjuvant Endocrine Therapy in Patients With High-Risk Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Primary Breast Cancer

PURPOSE

Everolimus, an oral inhibitor of the mammalian target of rapamycin, improves progression-free survival in combination with endocrine therapy (ET) in postmenopausal women with aromatase inhibitor-resistant metastatic breast cancer. However, the benefit of adding everolimus to ET in the adjuvant setting in early breast cancer is unknown.

PATIENTS AND METHODS

In this randomized double-blind phase III study, women with high-risk, hormone receptor-positive, human epidermal growth factor receptor 2-negative primary breast cancer were randomly assigned to everolimus or placebo for 2 years combined with standard ET. Stratification factors included ET agent, receipt of neoadjuvant versus adjuvant chemotherapy, progesterone receptor status, duration of ET before random assignment, and lymph node involvement. The primary end point was disease-free survival (DFS). The trial is registered with ClinicalTrials.gov (identifier: NCT01805271).

RESULTS

Between June 2013 and March 2020, 1,278 patients were randomly allocated to receive everolimus or placebo. At the first interim analysis, the trial was stopped for futility and a full analysis undertaken once data snapshot complete. One hundred forty-seven patients have had a DFS event reported and at 3 years, DFS did not differ between patients who received ET plus everolimus (88% [95% CI, 85 to 91]) or ET plus placebo (89% [95% CI, 86 to 91; hazard ratio, 0.95; 95% CI, 0.69 to 1.32; P = .77]). Grade ≥ 3 adverse events were reported in 22.9% of patients (29.9% with everolimus v 15.9% with placebo, P < .001). 53.4% everolimus-treated patients permanently discontinued experimental treatment early compared with placebo-treated 22.3%.

CONCLUSION

Among high-risk patients, everolimus added to adjuvant ET did not improve DFS. Tolerability was a concern, with more than half of patients stopping everolimus before study completion. Everolimus cannot be recommended in the adjuvant setting.

Switch to fulvestrant and palbociclib versus no switch in advanced breast cancer with rising ESR1 mutation during aromatase inhibitor and palbociclib therapy (PADA-1): a randomised, open-label, multicentre, phase 3 trial

BACKGROUND

In advanced oestrogen receptor-positive, HER2-negative breast cancer, acquired resistance to aromatase inhibitors frequently stems from ESR1-mutated subclones, which might be sensitive to fulvestrant. The PADA-1 trial aimed to show the efficacy of an early change in therapy on the basis of a rising ESR1 mutation in blood (bESR1^mut), while assessing the global safety of combination fulvestrant and palbociclib.

METHODS

We did a randomised, open-label, phase 3 trial in 83 hospitals in France. Women aged at least 18 years with oestrogen receptor-positive, HER2-negative advanced breast cancer and an Eastern Cooperative Oncology Group performance status of 0-2 were recruited and monitored for rising bESR1^mut during first-line aromatase inhibitor (2·5 mg letrozole, 1 mg anastrozole, or 25 mg exemestane, orally once per day, taken continuously) and palbociclib (125 mg orally once per day on days 1-21 of a 28-day cycle) therapy. Patients with newly present or increased bESR1^mut in circulating tumour DNA and no synchronous disease progression were randomly assigned (1:1) to continue with the same therapy or to switch to fulvestrant (500 mg intramuscularly on day 1 of each 28-day cycle and on day 15 of cycle 1) and palbociclib (dosing unchanged). The randomisation sequence was generated within an interactive web response system using a minimisation method (with an 80% random factor); patients were stratified according to visceral involvement (present or absent) and the time from inclusion to bESR1^mut detection (<12 months or ≥12 months). The co-primary endpoints were investigator-assessed progression-free survival from random assignment, analysed in the intention-to-treat population (ie, all randomly assigned patients), and grade 3 or worse haematological adverse events in all patients. The trial is registered with Clinicaltrials.gov (NCT03079011), and is now complete.

FINDINGS

From March 22, 2017, to Jan 31, 2019, 1017 patients were included, of whom 279 (27%) developed a rising bESR1^mut and 172 (17%) were randomly assigned to treatment: 88 to switching to fulvestrant and palbociclib and 84 patients to continuing aromatase inhibitor and palbociclib. At database lock on July 31, 2021, randomly assigned patients had a median follow-up of 35·3 months (IQR 29·2-41·4) from inclusion and 26·0 months (13·8-34·3) from random assignment. Median progression-free survival from random assignment was 11·9 months (95% CI 9·1-13·6) in the fulvestrant and palbociclib group versus 5·7 months (3·9-7·5) in the aromatase inhibitor and palbociclib group (stratified HR 0·61, 0·43-0·86; p=0·0040). The most frequent grade 3 or worse haematological adverse events were neutropenia (715 [70·3%] of 1017 patients), lymphopenia (66 [6·5%]), and thrombocytopenia (20 [2·0%]). The most common grade 3 or worse adverse events in step 2 were neutropenia (35 [41·7%] of 84 patients in the aromatase inhibitor and palbociclib group vs 39 [44·3%] of 88 patients in the fulvestrant and palbociclib group) and lymphopenia (three [3·6%] vs four [4·5%]). 31 (3·1%) patients had grade 3 or worse serious adverse events related to treatment in the overall population. Three (1·7%) of 172 patients randomly assigned had one serious adverse event in step 2: one (1·2%) grade 4 neutropenia and one (1·2%) grade 3 fatigue among 84 patients in the aromatase inhibitor and palbociclib group, and one (1·1%) grade 4 neutropenia among 88 patients in the fulvestrant and palbociclib group. One death by pulmonary embolism in step 1 was declared as being treatment related.

INTERPRETATION

PADA-1 is the first prospective randomised trial showing that the early therapeutic targeting of bESR1^mut results in significant clinical benefit. Additionally, the original design explored in PADA-1 might help with tackling acquired resistance with new drugs in future trials.

FUNDING

Pfizer.

ROSALINE: a phase II, neoadjuvant study targeting ROS1 in combination with endocrine therapy in invasive lobular carcinoma of the breast

Invasive lobular carcinoma (ILC) is the most common histologic subtype of breast cancer after invasive ductal carcinoma (i.e., no special type [NST]). ILC differs from NST in clinical presentation, site-specific metastases and response to conventional therapies. Loss of E-cadherin protein expression, due to alterations in its encoding gene CDH1, is the most frequent oncogenic event in ILC. Synthetic lethality approaches have shown promising antitumor effects of ROS1 inhibitors in models of E-cadherin-defective breast cancer in in vivo studies and provide the rationale for testing their clinical activity in patients with ILC. Entrectinib is a tyrosine kinase inhibitor targeting TRK, ROS1 and ALK tyrosine kinases. Here, the authors present ROSALINE (NCT04551495), a phase II study testing neoadjuvant entrectinib and endocrine therapy in women with estrogen receptor-positive, HER2-negative early ILC.

Real-Time Detection of ESR1 Mutation in Blood by Droplet Digital PCR in the PADA-1 Trial: Feasibility and Cross-Validation with NGS

The clinical actionability of circulating tumor DNA requires sensitive detection methods with a short turnaround time. In the PADA-1 phase 3 trial (NCT03079011), metastatic breast cancer patients treated with an aromatase inhibitor and palbociclib were screened every 2 months for activating ESR1 mutations in blood (bESR1_mut). We report the feasibility of the droplet digital polymerase chain reaction (ddPCR) and cross-validation with next-generation sequencing (NGS). bESR1_mut testing was centralized in two platforms using the same ddPCR assay. Results were reported as copies/mL of plasma and mutant allele frequency (MAF). We analyzed 200 positive ddPCR samples with an NGS assay (0.5-1% sensitivity). Overall, 12,552 blood samples were collected from 1017 patients from 83 centers. Among the 12,525 available samples with ddPCR results, 11,533 (92%) were bESR1_mut-negative. A total of 267 patients newly displayed bESR1_mut (26% patients/2% samples) with a median copy number of 14/mL (range: 4-1225) and a median MAF of 0.83% (0.11-35), 648 samples (20% patients/5% samples) displayed persistent bESR1_mut, and 77 (<1%) samples encountered a technical failure. The median turnaround time from blood drawing to result notification was 13 days (Q1:9; Q3:21 days). Among 200 ddPCR-positive samples tested, NGS detected bESR1_mut in 168 (84%); 25 of the 32 cases missed by NGS had low MAF and/or low coverage. In these 200 samples, bESR1_mut MAF by both techniques had an excellent intraclass correlation coefficient (ICC = 0.93; 95% CI [0.85; 0.97]). These results from a large-scale trial support the feasibility and accuracy of real-time bESR1_mut tracking by ddPCR, opening new opportunities for therapeutic interventions.

Randomised, open-label, multicentric phase III trial to evaluate the safety and efficacy of palbociclib in combination with endocrine therapy, guided by ESR1 mutation monitoring in oestrogen receptor-positive, HER2-negative metastatic breast cancer patients: study design of PADA-1

INTRODUCTION

The combination of a CDK4/6 inhibitor with an aromatase inhibitor (AI) has recently become the gold standard for AI-sensitive first line treatment of oestrogen receptor-positive (ER+) HER2-negative (HER2-) advanced breast cancer. However, most patients receiving this combination will ultimately progress and require further therapies.Several studies have demonstrated that the onset of a ESR1 gene mutation lead to AIs resistance in the advanced setting. ESR1 mutations can be detected in circulating tumour DNA (ctDNA) using a digital PCR assay. Our study aims to prove the clinical efficacy of periodic monitoring for emerging or rise of ESR1 mutations in ctDNA to trigger an early change from AI plus palbociclib to fulvestrant plus palbociclib treatment while assessing global safety.

METHODS

PADA-1 is a randomised, open-label, multicentric, phase III trial conducted in patients receiving AI and palbociclib as first line therapy for metastatic ER +HER2- breast cancer. 1000 patients will be included and treated with palbociclib in combination with an AI. Patients will be screened for circulating blood ESR1 mutation detection at regular intervals. Patients for whom a rising circulating ESR1 mutation is detected without tumour progression (up to N=200) will be randomised (1:1) between (1) Arm A: no modification of therapy; and (2) Arm B: palbociclib in combination with fulvestrant, a selective ER down-regulator. At tumour progression, an optional crossover will be offered to patients randomised in arm A. The coprimary endpoints are (1) Grade ≥3 haematological toxicities and their associations with baseline characteristics and (2) progression-free survival in randomised patients.

ETHICS AND DISSEMINATION

The study has been approved by the French medicines agency (ANSM) and by an ethics committee (ref 01/17_1 CPP Ouest-IV Nantes) in January 2017. The trial results will be published in academic conference presentations and international peer-reviewed journals.

TRIAL REGISTRATION NUMBERS

EudraCT: 2016-004360-18; NCT03079011.

Abstract PD9-08: Prognostic value of EndoPredict test in patients screened for UNIRAD, a UCBG randomized, double blind, phase III international trial evaluating the addition of everolimus (EVE) to adjuvant hormone therapy (HT) in women with high risk HR+, HER2- early breast cancer (eBC)

Background: The double blind randomized UNIRAD trial (NCT01805271) showed no evidence that adding Everolimus (EVE) to adjuvant endocrine therapy (EHT) for high-risk early breast cancer (BC) improved 3-year disease-free survival (iDFS) compared with EHT alone. In this trial, high risk was defined by any T and either ≥4N+, or ≥1N+ after neoadjuvant treatment, or ≥1N+ and EPclin high risk (EPCH) score ≥3.3. This sub analysis is aimed to verify prognostic added value of EndoPredict test results on outcomes in patients screened for the UNIRAD study.. Material and methods: From May 2015 to March 2020, 777 patients were screened with the EndoPredict test. Complete results were obtained for 767 of them. 662 pts were classified as EPCH and 429 were randomized in UNIRAD. 233 pts with EPCH and 105 pts with EPclin low risk (EPCL) were not randomized but followed up for iDFS. Statistical analysis: Kaplan-Meier estimates the association of the integrated molecular-clinico-pathologic EPclin score, and the 12-gene molecular EP score, with iDFS (primary endpoint) and dMFS (secondary endpoint). Independent prognostic added value of EPclin score was tested in a multivariate Cox model after adjusting on tumor characteristics (Grade and T, N). A two-sided p-value less than 0.05 considered as statistically significant, 95% confidence intervals reported with HR. Results: Median follow-up of the cohort was 36.6 mo (0-69) since EndoPredict test. As for the whole population, there was no significant difference in iDFS between treatment arms in the randomized EPCH group. On the other hand, EPclin was an independent prognostic factor for iDFS. 36 mo relapse rate from testing for patients in the EPCL group and the EPCH group was 0% and 7%, respectively (HR supposing continuous EPclin score: 2.36, 95%CI: 1.7-3.3, p &lt; .0001). This difference remained significant when assessed in a cox model with tumor size, number of positive nodes and tumor grade (HR: 1.96, 95%CI: 1.32-2.9, p=0.0008). Furthermore, EPclin results was independently correlated to distant metastatic free survival: 36 mo dMFS for patient in the EPCL and EPCH group was 100% and 94%, respectively (adjusted HR: 2.13, 95%CI:11.3-3.4, p = .0014). Of interest when assessing prognostic of patients within quartiles of EPclin Score (&lt;3.6; 3.6-4.1; ≥4.1-4.8; ≥ 4.8), 36 mo iDFS was 99%; 95%; 94% and 86%, respectively. Conclusion: These prospective results confirm the significance of EPclin score as an independent prognostic parameter in node positive ER+/HER2- eBC patients receiving standard adjuvant treatment. This information can be of importance for selection of specific adjuvant intervention, particularly chemotherapy and new targeted therapy. Further analysis on the EP score will be presented at the meeting.

Citation Format: Frederique Penault-Llorca, Florence Dalenc, Sylvie Chabaud, Paul Cottu, Djelila Allouache, David Cameron, Jean-Philippe Jacquin, Julien Grenier, Laurence Venat Bouvet, Apurna Jegannathen, Mario Campone, Francesco Del Piano, Marc Debled, Anne-Claire Hardy-Bessard, Sylvie Giacchetti, Philippe Barthelemy, Laure Kaluzinski, Audrey Mailliez, Marie-Ange Mouret-Reynier, Eric Legouffe, Anne Cayre, Mathilde Martinez, Catherine Delbaldo, Delphine Mollon-Grange, E. Jane Macaskill, Matthew Sephton, Laëtitia Stefani, Blaha Belgadi, Matthew Winter, Hubert Orfeuvre, Magali Lacroix-Triki, Herve Bonnefoi, Judith Bliss, Jean-Luc Canon, Jerome Lemonnier, Fabrice Andre, Thomas Bachelot. Prognostic value of EndoPredict test in patients screened for UNIRAD, a UCBG randomized, double blind, phase III international trial evaluating the addition of everolimus (EVE) to adjuvant hormone therapy (HT) in women with high risk HR+, HER2- early breast cancer (eBC) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr PD9-08.

Abstract P2-14-12: B-immune interim analysis: A phase Ib/II study of durvalumab combined with dose-dense EC in a neoadjuvant setting for patients with locally advanced luminal B HER2(-) or triple negative breast cancers

Background: The association of immune checkpoints inhibitors (ICI) and dose dense chemotherapy is a promising combination in a neoadjuvant setting for triple negative breast cancers (TNBC). However, response rates vary from one study to another and timing, best chemotherapy partner and efficacy in breast cancer subtypes considered as less immunogenic, like luminal B tumors, should be further investigated. The B-immune study evaluates a neoadjuvant treatment with paclitaxel followed by a short combination of an anti-PD-L1 antibody with anthracyclines for TNBC and luminal B breast cancers (BC). Method: B-immune (NCT03356860), a multicentric phase Ib/II prospective trial, includes patients with stage I to III luminal B or TNBC treated with paclitaxel 80mg/m2 weekly from week 1 to 12 followed by 4 cycles of epirubicine 90mg/m2 and cyclophosphamide 600 mg/m2 (EC) Q2W in a neoadjuvant setting. The phase Ib evaluated a single infusion of durvalumab (anti-PD-L1) combined with the 3rd cycle of EC. The phase II, in progress, evaluates 2 infusions of durvalumab with the 1st and 3rd cycle of EC respectively. Surgery is planned 3 weeks after the last preoperative treatment. Primary objectives are safety and efficacy based on pathological complete response (pCR) rate. Considering a 2-stage Simon design, 22 TNBC patients are needed in the phase II to detect a pCR rate increase from 30% to 60% and 24 luminal B BC patients are needed to detect a pCR rate increase from 15% to 40% (α = 0.1 and β = 0.1). At least 3 pCRs must be observed among 8 TNBC patients and 2 among 10 Luminal B patients treated in the 1st stage to move to the 2nd stage. Results: This analysis concerns 3 treated patients from phase Ib and 18 from phase II who received the experimental treatment (median age 55 y-old, 10 TNBC, 11 Luminal B, 14% stage I, 67% stage II, 19% stage III). Overall, 169 AEs were reported and 22 (13%) were graded &gt; 2 on 10/21 patients, including 27% of neutropenia (6/22), 22% of anemia (5/22), 13% of severe asthenia (3/22) and 9% of diarrhea (2/22). Four patients (19%) developed thyroid immune endocrine disorders. Efficacy was evaluated on 18 patients included in the 1st stage of phase II (8 TNBC and 10 luminal B). Five among 8 TNBC patients (62%) and 2 among 10 luminal B patients (20%) had a pCR. Conclusions: The B-immune interim analysis reveals an acceptable global safety profile. Reported immune related adverse events were limited to thyroid endocrine disorders. Observed pCR rate after neoadjuvant paclitaxel followed by 2 durvalumab infusions combined to EC chemotherapy warrants pursuing the trial for the TNBC and luminal B cohorts.

Citation Format: Javier Carrasco, Claire Quaghebeur, Stephanie Henry, Christine Galant, Mieke Van Bockstal, Paul Delrée, Brigitte Honhon, Dominique Korman, Vincent Verschaeve, Christophe Lonchay, Sarah Levefre, Lionel D'hondt, Martine Berliere, Sophie Delmarcelle, Jean-Michel Mine, Timour Willems, Gebhard Müller, Nathalie Myant, Isabelle Bar, Manuel Constant, Sandy Haussy, Alix Devaux, Pierre Coulie, Jean-Luc Canon, François Duhoux. B-immune interim analysis: A phase Ib/II study of durvalumab combined with dose-dense EC in a neoadjuvant setting for patients with locally advanced luminal B HER2(-) or triple negative breast cancers [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-14-12.

Abstract GS3-05: Fulvestrant-palbociclib vs continuing aromatase inhibitor-palbociclib upon detection of circulating ESR1 mutation in HR+ HER2- metastatic breast cancer patients: Results of PADA-1, a UCBG-GINECO randomized phase 3 trial

Background: ESR1 mutations are known drivers of resistance to first line aromatase inhibitors (AI)-based therapy in hormone receptor-positive (HR+) HER2- metastatic breast cancer (mBC) patients (pts), but their clinical actionability remains unknown. The randomized phase 3 PADA-1 trial aimed at evaluating the clinical benefit associated with a switch to fulvestrant-palbociclib upon the detection of a rising ESR1 mutation in blood (bESR1mut) in HR+ HER2- mBC pts treated by first line AI-palbociclib.. Methods: PADA-1 (NCT03079011), a multicenter, randomized, open-label, phase 3 trial, enrolled HR+ HER2- mBC pts with no prior therapy for mBC in the absence of AI-resistance. In the first step, pts were treated with AI-palbociclib as first line therapy and underwent centralized bESR1mut screening every two months. Rising bESR1mut+ pts with no clinical/imaging concomitant disease progression were included in the second step, in which they were randomized between continuing the same therapy (standard arm) or switching to fulvestrant-palbociclib (experimental arm). The third step consisted in an optional crossover to fulvestrant-palbociclib following tumor progression for patients randomized in the standard arm. PADA-1 co-primary endpoints were PFS in the second step, and global safety.. Results: Between 03/2017 and 01/2019, 1,017 pts have been included in the first step. After a median time of 15.6 months in the first step, 172 pts with rising bESR1mut and no synchronous disease progression were randomized to continuing AI-palbociclib (N=84 pts) or to fulvestrant-palbociclib (N=88 pts). Among the 172 randomized pts, N=136 PFS events have been observed in the second step after a median follow-up of 26 months. The median PFS was 5.7 months (95%CI[3.9;7.5]) in the AI-palbociclib arm and 11.9 months (95%CI[9.1;13.6]) in the fulvestrant-palbociclib arm (HR=0.63; 95%CI|0.45-0.88], p=0.007). Among the 70 patients who subsequently developed a disease progression in the AI-palbociclib arm, 47 were included in the optional crossover cohort. With a median follow-up of 14.7 months and 37 events, the median second-PFS observed in the cross-over cohort was 3.5 months (95%CI [2.7-5.1]). Treatment safety and validation of the ESR1mut assay are reported separately (poster session #1). Conclusion: PADA-1 reached its primary objective. This first-of-its-kind liquid biopsy-based trial demonstrates that targeting bESR1mut-associated resistance through a change in the endocrine partner of palbociclib is feasible and allows a doubling in the subsequent median progression free survival.. Funding: Pfizer

Citation Format: François-Clément Bidard, Anne-Claire Hardy-Bessard, Thomas Bachelot, Jean-Yves Pierga, Jean-Luc Canon, Florian Clatot, Fabrice Andre, Thibault De La Motte Rouge, Barbara Pistilli, Florence Dalenc, Nadine Dohollou, Olivier Arsene, Thierry Petit, Cécilia Riedl, François Morvan, Adina Marti, Emma Lachaier, Mihaela Achille, Michel Gozy, Anne Escande, Dominique Mille, Fanny Trouboul, Laurent Arnould, Ivan Bieche, Anne Pradines, Jerome Lemonnier, Frederique Berger, Suzette Delaloge. Fulvestrant-palbociclib vs continuing aromatase inhibitor-palbociclib upon detection of circulating ESR1 mutation in HR+ HER2- metastatic breast cancer patients: Results of PADA-1, a UCBG-GINECO randomized phase 3 trial [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr GS3-05.

Abstract P1-18-16: First line aromatase inhibitor (AI) + palbociclib with randomized switch to fulvestrant + palbociclib upon detection of circulating ESR1 mutation in HR+ HER2- metastatic breast cancer patients: Global safety results of PADA-1, a UCBG-GINECO phase III trial

Background: Aromatase inhibitors (AI) in combination with a CDK 4/6 inhibitor have been established as the standard first line treatment of non AI-resistant hormone receptor-positive (HR+) HER2- metastatic breast cancer (mBC) patients (pts). ESR1 mutations are known drivers of resistance to AIs in the metastatic setting but their actionability remains unknown. The phase 3 PADA-1 trial aimed both at refining the global safety of palbociclib combined to any AI as first line treatment of HR+ HER2- mBC pts, and at evaluating the clinical benefit associated with a switch to fulvestrant-palbociclib upon detection of a rising ESR1 mutation in blood (bESR1mut). Methods: PADA-1 (NCT03079011), a multicenter, randomized, open-label, phase 3 trial, enrolled HR+ HER2- mBC pts with no prior therapy for mBC, in the absence of AI-resistance. In the first step, pts received a combination of any AI and palbociclib at standard recommended doses and underwent centralized bESR1mut screening every two months. In the second step, bESR1mut+ pts with no clinical/imaging concomitant disease progression were randomized between continuing the same therapy (standard arm) or switching to fulvestrant-palbociclib (experimental arm). The third step consisted in an optional cross-over after tumor progression for patients randomized in the standard arm. PADA-1 co-primary endpoints were global safety of the combination of palbociclib + endocrine therapy in the whole population of patients, throughout the study, with focus on hematological toxicities; and PFS in the second step. We present here the results of the global safety co-primary endpoint. Results: From 3/2017 to 01/2019, 1017 pts were accrued in 83 sites. As per 05/2021, 272 pts were still in step 1, 35 in step 2, and 8 in step 3. The overall follow-up was 33.7 months. 232 pts have deceased. 333 SAEs have been reported, including 21 grade 5, 35 grade 4, 183 grade 3, 53 grade 2, 26 grade 1 and 15 unknown grade. Among the grade 5 cases, 2 have been declared as potentially related to the underlying treatment (Death of unknown cause, pulmonary embolism). No pt died of SARS-CoV2 infection. The main hematological toxicities encountered, as well as selected non-hematological events are described in Table 1. Permanent discontinuation of the treatment due to toxicity occurred in 39 pts/1017 (3.8%). Palbociclib dose decreases occurred in 419 (41.2%) pts. Conclusion: By the number of included patients, PADA-1 is the largest prospective trial with 1st line AI and palbociclib. Data confirm the favorable safety profile of palbociclib when combined to any AI +/- switch to fulvestrant. Hematological toxicity appears limited and is mostly restricted to non-clinically significant neutropenia. Permanent discontinuation was exceptional. Detailed per-step analyses will be presented.

Table 1.Adverse events (% pts)Grade 3, N (%)Grade 4, N (%)Neutropenia628 (61.8%)83 (8.2%)Febrile neutropenia4 (0.4%)0Thrombocytopenia18 (1.8%)3 (0.3%)Anemia24 (2.4%)0Lymphocytopenia58 (5.7%)5 (0.5%)Insterstitial lung disease4 (0.4%)0Liver enzymes increase (AST/ALT)5 (0.5%)0Mucositis10 (1%)0

Citation Format: Suzette Delaloge, Anne-Claire Hardy-Bessard, Thomas Bachelot, Jean-Yves Pierga, Jean-Luc Canon, Florian Clatot, Fabrice André, Thibault De La Motte Rouge, Barbara Pistilli, Florence Dalenc, Nadine Dohollou, Olivier Arsene, Thierry Petit, Cecilia Riedl, François Morvan, Adina Marti, Emma Lachaier, Mihaela Achille, Michel Gozy, Anne Escande, Dominique Mille, Fanny Trouboul, Sandrine Marques, Jerome Lemonnier, Frederique Berger, François-Clément Bidard. First line aromatase inhibitor (AI) + palbociclib with randomized switch to fulvestrant + palbociclib upon detection of circulating ESR1 mutation in HR+ HER2- metastatic breast cancer patients: Global safety results of PADA-1, a UCBG-GINECO phase III trial [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-18-16.

Impact of the line of treatment on progression-free survival in patients treated with T-DM1 for metastatic breast cancer

Background

Trastuzumab emtansine (T-DM1) is indicated as second-line treatment for human epidermal growth factor receptor 2 (HER2)-positive metastatic or unresectable locally advanced breast cancer, after progression on trastuzumab and a taxane-based chemotherapy.

We wished to determine if the line of treatment in which T-DM1 is administered has an impact on progression-free survival (PFS) and in particular, if prior treatment with capecitabine/lapatinib or pertuzumab modifies PFS of further treatment with T-DM1.

Patients and methods

We performed a multicenter retrospective study in 3 Belgian institutions. We evaluated PFS with T-DM1 in patients treated for HER2 positive metastatic or locally advanced unresectable breast cancer between January 1, 2009 and December 31, 2016.

Results

We included 51 patients. The median PFS was 9.01 months. The line of treatment in which T-DM1 (1st line, 2nd line, 3rd line or 4+ lines) was administered had no influence on PFS (hazard ratio 0.979, CI95: 0.835–1.143).

There was no significant difference in PFS whether or not patients had received prior treatment with capecitabine/lapatinib (9.17 vs 5.56 months, p-value 0.875).

But, patients who received pertuzumab before T-DM1 tended to exhibit a shorter PFS (3.55 months for T-DM1 after pertuzumab vs 9.50 months for T-DM1 without pretreatment with pertuzumab), even if this difference was not statistically significant (p-value 0.144).

Conclusion

Unlike with conventional chemotherapy, the line of treatment in which T-DM1 is administered does not influence PFS in our cohort of patients with advanced HER2-positive breast cancer.

A phase II study of monalizumab in patients with recurrent/metastatic squamous cell carcinoma of the head and neck: The I1 cohort of the EORTC-HNCG-1559 UPSTREAM trial

PURPOSE

Monalizumab is a monoclonal antibody targeting the inhibitory natural killer group 2A (NKG2A) receptor localised on natural killer (NK) and T cells. Its ligand, the human leukocyte antigen E (HLA-E), is overexpressed in squamous cell carcinoma of the head and neck (SCCHN). By targeting the HLA-E-NKG2A pathway, monalizumab may enhance NK and T cell activity.

EXPERIMENTAL DESIGN

The UPSTREAM trial is a biomarker-driven umbrella trial studying targeted therapies and immunotherapies in patients with recurrent/metastatic (R/M) SCCHN progressing after platinum therapy. The immunotherapy 1 (I1) cohort was a phase II, single-arm substudy evaluating monalizumab (10 mg/kg intravenously on day 1 of a 14-day cycle). The primary end-point was the objective response (OR) rate (Response Evaluation Criteria in Solid Tumours 1.1) over the first 16 weeks. A two-stage Simon design was used (H1 15%, H0 3%, α 8%, power 90%) with pre-planned interruption of accrual if no OR was observed after the first 25 patients.

RESULTS

Twenty-six eligible patients were enrolled. Seventeen (65%) patients had received ≥2 previous lines of systemic treatment, and 15 (58%) patients were PD(-L)1 inhibitor pretreated. No OR was observed. Stable disease was observed in 6 patients (23%) with a median duration of 3.8 months (95% confidence interval [CI]: 2.7-NE). The median progression-free survival and overall survival were 1.7 months (95% CI: 1.5-1.8) and 6.7 months (95% CI: 3.0-9.6), respectively. The most frequent treatment-related adverse event was grade I/II fatigue (19%).

CONCLUSIONS

Monalizumab monotherapy has limited activity in R/M SCCHN. The I1 cohort did not meet its primary objective. Monalizumab combined with durvalumab is under investigation within UPSTREAM.

Sapanisertib Plus Exemestane or Fulvestrant in Women with Hormone Receptor-Positive/HER2-Negative Advanced or Metastatic Breast Cancer

PURPOSE

This open-label, multicenter, phase IB/II study evaluated sapanisertib, a dual inhibitor of mTOR kinase complexes 1/2, plus exemestane or fulvestrant in postmenopausal women with hormone receptor-positive (HR⁺)/HER2-negative (HER2^-) advanced/metastatic breast cancer.

PATIENTS AND METHODS

Eligible patients had previously progressed on everolimus with exemestane/fulvestrant and received ≤3 (phase IB) or ≤1 (phase II) prior chemotherapy regimens. Patients received sapanisertib 3 to 5 mg every day (phase IB), or 4 mg every day (phase II) with exemestane 25 mg every day or fulvestrant 500 mg monthly in 28-day cycles. Phase II enrolled parallel cohorts based on prior response to everolimus. The primary objective of phase II was to evaluate antitumor activity by clinical benefit rate at 16 weeks (CBR-16).

RESULTS

Overall, 118 patients enrolled in phase IB (n = 24) and II (n = 94). Five patients in phase IB experienced dose-limiting toxicities, at sapanisertib doses of 5 mg every day (n = 4) and 4 mg every day (n = 1); sapanisertib 4 mg every day was the MTD in combination with exemestane or fulvestrant. In phase II, in everolimus-sensitive versus everolimus-resistant cohorts, CBR-16 was 45% versus 23%, and overall response rate was 8% versus 2%, respectively. The most common adverse events were nausea (52%), fatigue (47%), diarrhea (37%), and hyperglycemia (33%); rash occurred in 17% of patients. Molecular analysis suggested positive association between AKT1 mutation status and best treatment response (complete + partial response; P = 0.0262).

CONCLUSIONS

Sapanisertib plus exemestane or fulvestrant was well tolerated and exhibited clinical benefit in postmenopausal women with pretreated everolimus-sensitive or everolimus-resistant breast cancer.

Tumor sequencing is useful to refine the analysis of germline variants in unexplained high-risk breast cancer families

Background

Multigene panels are routinely used to assess for predisposing germline mutations in families at high breast cancer risk. The number of variants of unknown significance thereby identified increases with the number of sequenced genes. We aimed to determine whether tumor sequencing can help refine the analysis of germline variants based on second somatic genetic events in the same gene.

Methods

Whole-exome sequencing (WES) was performed on whole blood DNA from 70 unrelated breast cancer patients referred for genetic testing and without a BRCA1, BRCA2, TP53, or CHEK2 mutation. Rare variants were retained in a list of 735 genes. WES was performed on matched tumor DNA to identify somatic second hits (copy number alterations (CNAs) or mutations) in the same genes. Distinct methods (among which immunohistochemistry, mutational signatures, homologous recombination deficiency, and tumor mutation burden analyses) were used to further study the role of the variants in tumor development, as appropriate.

Results

Sixty-eight patients (97%) carried at least one germline variant (4.7 ± 2.0 variants per patient). Of the 329 variants, 55 (17%) presented a second hit in paired tumor tissue. Of these, 53 were CNAs, resulting in tumor enrichment (28 variants) or depletion (25 variants) of the germline variant. Eleven patients received variant disclosure, with clinical measures for five of them. Seven variants in breast cancer-predisposing genes were considered not implicated in oncogenesis. One patient presented significant tumor enrichment of a germline variant in the oncogene ERBB2, in vitro expression of which caused downstream signaling pathway activation.

Conclusion

Tumor sequencing is a powerful approach to refine variant interpretation in cancer-predisposing genes in high-risk breast cancer patients. In this series, the strategy provided clinically relevant information for 11 out of 70 patients (16%), adapted to the considered gene and the familial clinical phenotype.

Abstract P5-03-03: Tumor sequencing is useful to reclassify germline variants in unexplained high-risk breast cancer families

BACKGROUND Multigene panels are routinely used to search for predisposing mutations in families considered at high risk of breast cancer. The number of variants of unknown significance (VUS) thereby identified increases with the number of sequenced genes. We aimed to determine whether tumor sequencing can help reclassify germline VUS based on second events hitting the same gene. METHODS Whole-exome sequencing (WES) was performed on whole-blood DNA from 70 unrelated breast cancer patients referred for genetic testing and without BRCA1, BRCA2, TP53 or CHEK2 mutations. Rare variants considered as a VUS based on ACMG guidelines were retained in a list of 735 genes. WES was performed on matched tumor DNA to look for somatic second hits (copy number alteration or second mutation) in the same genes. RESULTS Sixty-eight patients (97%) carried at least one germline VUS (4.7 ± 2.0 variants per patient). Of the 329 VUS, 55 (17%) presented a somatic second hit in the paired tumor tissue. Two were a second somatic mutation, whereas 53 were copy number alterations. This resulted in relative tumor enrichment or depletion of the germline variant for 28 and 25 VUS, respectively. Estimation of tumor mutation burden and homologous recombination deficiency through mutational signatures and allelic imbalance analysis could highlight bi-allelic gene inactivation in relevant cases. Clinical measures were proposed for six patients carrying a germline variant on PALB2, PMS2, PMS1, MUTYH or NTHL1. Variant disclosure without clinical measures was proposed for five patients carrying a variant on MRE11A, ATM, WRN or TP53 (functional testing ongoing for the latter). Germline and tumor DNA analysis of an affected relative of the patient carrying the germline MRE11A variant demonstrated the co-segregation of the variant as well as the presence of the same somatic second hit. Seven VUS on clinically actionable breast cancer predisposing genes (PALB2, BRCA2, CDH1, ATM and BARD1) were downgraded to probably benign variants as the germline variant was depleted in the tumor. One patient presented a significant tumor enrichment of a germline VUS in the C-terminal domain of the oncogene ERBB2. In vitro expression of this variant caused downstream signaling pathway activation. CONCLUSION Tumor sequencing is a powerful approach to refine VUS in cancer-predisposing genes in high-risk breast cancer patients. In this series, the strategy provided clinically relevant information for 11 out of 70 patients (16%).

Citation Format: Cedric Van Marcke, Raphaël Helaers, Céline A Schoonjans, Martine Berlière, Anne De Leener, Jean-Luc Canon, Peter Vuylsteke, Jean-Pascal Machiels, Nisha Limaye, Miikka Vikkula, Francois P Duhoux. Tumor sequencing is useful to reclassify germline variants in unexplained high-risk breast cancer families [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-03-03.

Abstract P5-03-04: Co-segregation of rare possibly-damaging variants in cancer-related genes correlates with phenotypic homogeneity in familial breast cancer

BACKGROUND Breast cancer (BC) is a complex disease. While Mendelian mutations in high-penetrance genes predispose to some familial forms, others are due to multiple common low-penetrance polymorphisms. However, it is unclear if the combination of some rare coding variants has an effect. As some Mendelian forms demonstrate genotype-phenotype correlations, we hypothesized co-segregation of rare variants in cancer-related genes would be more frequent in high-risk families with a uniform BC phenotype among relatives. METHODS Whole-exome sequencing was performed on germline DNA from unrelated BC patients referred for genetic testing but without a causative mutation and for which DNA was available from at least one second relative with BC. We retained rare (&lt; 1.5% in ExaC) in silico possibly damaging variants (splice alteration, nonsense or frameshift mutation, or missense variant considered deleterious by at least 2 different algorithms) in a list of 735 cancer or DNA repair related genes. We assessed correlation between segregation of these variants in affected relatives (studied by Sanger sequencing) and tumor phenotypes. A familial uniform BC phenotype was denoted as sharing the same BC histology and the same clinical molecular classification, based on the expression of the hormone receptors and HER2. RESULTS Of the 54 families, 23 (43%) presented a uniform phenotype across the affected relatives. We identified 251 variants. The mean number of variants tested did not differ between families with a similar BC phenotype and families with different BC phenotypes (4.3 vs 4.9 respectively, two-sided T-test p=0.19). The proportion of disease co-segregating variants inside each family was however significantly higher in families with a uniform BC phenotype than in families with a heterogeneous BC phenotype (57.8% vs 30.2%, p&lt;0.01 adjusted for the number of relatives and meioses within each family). Sequencing of matched tumor DNA, obtained for 44 probands, revealed co-segregating variants were more frequently enriched by a somatic event (18.6 vs 4.5%, Mann-Whitney test p=0.042 and 8.3 vs 1.1%, p=0.031 for the families with a uniform or a heterogeneous breast cancer phenotype, respectively). CONCLUSION In this cohort of families at high risk of BC, the proportion of co-segregating variants was significantly higher in the families in which the affected relatives shared a uniform BC phenotype. Investigation of oligogenic models could be more pertinent in this subgroup of families. The theory of bi-allelic gene inactivation required to drive cancer, shown for several Mendelian genes, could also be pertinent in the oligogenic model of inheritance. This study should be replicated in an independent cohort for confirmation.

Citation Format: Cedric Van Marcke, Raphaël Helaers, Céline A Schoonjans, Jérôme Ambroise, Martine Berlière, Jean-Luc Canon, Peter Vuylsteke, Jean-Pascal Machiels, Miikka Vikkula, Francois P Duhoux. Co-segregation of rare possibly-damaging variants in cancer-related genes correlates with phenotypic homogeneity in familial breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-03-04.

Abstract P5-11-22: Clinical and biological efficacy of first line AI and palbociclib in ER+ HER2- MBC with detectable circulating ESR1 mutation prior to treatment initiation

Background: In ER+ HER2- metastatic breast cancer (MBC), activating ESR1 mutations (ESR1mut) confer resistance to aromatase inhibitors (AI) when used as single agent. The impact of ESR1mut, when detected at baseline (prior to the initiation of therapy), on the efficacy of first line combined AI- CDK4/6 inhibitor therapy remains however unknown.

Methods: The PADA-1 phase 3 trial (NCT03079011) aims at evaluating the utility of monitoring the onset of ESR1mut in cell-free DNA (cfDNA) from patients (pts) receiving AI-palbociclib, as a biomarker to trigger a switch from AI to fulvestrant. Main inclusion criteria were pts with no prior therapy for MBC and with no overt resistance to AI (i.e. no adjuvant AI or adjuvant AI completed &gt;12 months prior to the metastatic relapse). The present exploratory analysis evaluated the biological and clinical outcome of patients who tested positive for ESR1mut at baseline (before any treatment).

Results: From 04/2017 to 01/2019, N=1017 ER+ HER2- MBC pts were included and had their cfDNA tested for ESR1mut at inclusion and during therapy (at 1 month and then every 2 months). N=33/1017 pts had a detectable circulating ESR1mut at inclusion (3.2%, 95%CI [2.2;4.5]), with a median allelic frequency (AF) of 2.5% (range: 0.1- 46%). First, we evaluated the kinetics of ESR1mut in the 33 ESR1mut-positive pts at inclusion. N=1 pt died after 1 month on treatment. In N=25/32 pts (78%), ESR1mut became undetectable (AF&lt;0.1%) within the first 5 months on treatment, with a median time to ESR1mut ‘clearance’ in cfDNA of 34 days 95%CI[29;91d]. Among these 25 pts, with a median follow-up of 10 months (range 0-25.1m): 14 pts (56%) had ESR1mut detected again in cfDNA during AI-palbociclib therapy; 2 pts (8%) experienced a disease progression with no ESR1mut detected; the remaining 9 patients (36%) are still both ESR1mut -free and disease progression-free at time of analysis. Secondly, we evaluated the prognostic impact of cfDNA ESR1mut status at inclusion on progression-free survival (PFS) under AI palbociclib treatment, with an overall median follow-up time of 12.4 months (range: 0-25.3m). The 33 ESR1mut-positive pts experienced a shorter PFS (median PFS: 17.5mo, 95%CI=[10.5-NR]) than the 984 ESR1mut-negative pts (median PFS not reached), with an estimated HR= 2.8, 95%CI=[1.6;5].

Conclusions: ESR1mut are rarely detected in the cfDNA of ER+ HER2- MBC patients with no overt resistance to AI. The quick ‘clearance’ of ESR1mut observed in most patients following treatment initiation and the observed 17.5 months-long median PFS both suggest that the AI palbociclib combination retain clinical activity in ESR1mut-positive MBC. However, in most patients, these mutations were eventually detected again later during therapy and ESR1mut- positivity was associated with a significantly shorter PFS, suggesting that ESR1mut positivity at baseline could accelerate the onset of resistance to AI-palbociclib.

Funding: Pfizer

Citation Format: François-Clément Bidard, Céline Callens, Florence Dalenc, Barbara Pistilli, Thibault de la Motte Rouge, Florian Clatot, Véronique D'Hondt, Luis Teixeira, Sibille Everhard, Hélène Vegas, Jérôme Lemonnier, Ivan Bieche, Anne Pradines, Jean-François Paitel, Dominique Spaeth, Jean-Luc Canon, Isabelle Moullet, Jean-Yves Pierga, Frédérique Berger, Thomas Bachelot, Suzette Delaloge. Clinical and biological efficacy of first line AI and palbociclib in ER+ HER2- MBC with detectable circulating ESR1 mutation prior to treatment initiation [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-11-22.

MiR-210 Is Overexpressed in Tumor-infiltrating Plasma Cells in Triple-negative Breast Cancer

Triple-negative breast cancer (TNBC) is a heterogeneous group of breast cancer and is characterized by aggressiveness and poor prognosis. MicroRNA represents a new class of biomarkers, and accumulating evidence indicates that microRNAs contribute to tumorigenesis and cancer metastasis. It has been described that miR-210 is highly expressed in TNBC, and its overexpression had been linked to poor prognosis. In a previous work, we showed that in TNBC miR-210 is expressed in tumor cells and also in the tumor microenvironment (TME), particularly in inflammatory CD45-LCA positive cells. However, the exact identity of these cells remained unknown. In this study, we performed in situ hybridization and immunohistochemistry using validated antibodies for the different specific immune cell markers on adjacent sections of 23 TNBC infiltrated with immune cells. We found that miR-210 expressing cells in the TME were stained positive with CD79a, a B-cell lineage marker. These tumor-infiltrating cells were negative for CD20 and Ki-67 but positive for MUM1 and CD38 and also expressed immunoglobulins, indicating that they are immunoglobulin-producing plasma cells (PCs). To the best of our knowledge, this is the first study demonstrating miR-210 expression in tumor-infiltrating PCs.

UCBG 2-04: Long-term results of the PACS 04 trial evaluating adjuvant epirubicin plus docetaxel in node-positive breast cancer and trastuzumab in the human epidermal growth factor receptor 2-positive subgroup

PURPOSE

We conducted a double-randomised phase III trial to evaluate a concomitant taxane-anthracycline regimen in node-positive breast cancer and the efficacy of trastuzumab in the human epidermal growth factor receptor 2 (HER2)-positive subpopulation.

METHODS

A total of 3010 patients with node-positive breast cancer were randomly assigned to receive 6 cycles of 500 mg/m² of fluorouracil, 100 mg/m² of epirubicin and 500 mg/m² of cyclophosphamide (FEC) or 75 mg/m² of epirubicin and 75 mg/m² of docetaxel (ED). Patients with HER2-positive tumours were secondary randomly assigned to either trastuzumab or observation. The primary end-point was disease-free survival (DFS) in the two chemotherapy arms.

RESULTS

After a 115-month median follow-up, DFS was not significantly better in the ED arm (DFS: 70%, 95% confidence interval [CI]: 67-72) than in the FEC arm (DFS: 68%, 95% CI: 65-70; hazard ratio [HR] = 0.88, 95% CI: 0.77-1.01; p = 0.064). The OS was not different between FEC (OS: 80%, 95% CI: 78-83) and ED (OS: 81%, 95% CI: 79-83); HR = 0.97, 95% CI: 0.81-1.16; p = 0.729). ED appeared more toxic. In the 528 HER2-positive subset, there was trend for a higher DFS, in the intention-to-treat population, in the trastuzumab arm (DFS: 68%, 95% CI: 61-74) than in the observation arm (DFS: 60%, 95% CI: 54-66; HR = 0.77, 95% CI: 0.57-1.03; p = 0.079). In the per-protocol population, DFS was significantly higher in the trastuzumab arm (DFS: 70%, 95% CI: 63-76) than in the observation arm (DFS: 59%, 95% CI: 53-65; HR = 0.69, 95% CI: 0.51-0.94; p = 0.0156). The OS was not different between these 2 arms.

CONCLUSION

This study did not show superiority of the concomitant anthracycline-taxane arm which was more toxic in high-risk node-positive breast cancer patients. Long-term results of the HER2-positive subpopulation are in line with those of the other adjuvant trastuzumab trials but quantitatively less pronounced mostly because of lack of power.

Chimeric Antigen Receptor-T Cells for Targeting Solid Tumors: Current Challenges and Existing Strategies

Chimeric antigen receptor-T cells (CAR-Ts) are an exciting new cancer treatment modality exemplified by the recent regulatory approval of two CD19-targeted CAR-T therapies for certain B cell malignancies. However, this success in the hematological setting has yet to translate to a significant level of objective clinical responses in the solid tumor setting. The reason for this lack of translation undoubtedly lies in the substantial challenges raised by solid tumors to all therapies, including CAR-T, that differ from B cell malignancies. For instance, intravenously infused CAR-Ts are likely to make rapid contact with cancerous B cells since both tend to reside in the same vascular compartments within the body. By contrast, solid cancers tend to form discrete tumor masses with an immune-suppressive tumor microenvironment composed of tumor cells and non-tumor stromal cells served by abnormal vasculature that restricts lymphocyte infiltration and suppresses immune function, expansion, and persistence. Moreover, the paucity of uniquely and homogeneously expressed tumor antigens and inherent plasticity of cancer cells provide major challenges to the specificity, potency, and overall effectiveness of CAR-T therapies. This review focuses on the major preclinical and clinical strategies currently being pursued to tackle these challenges in order to drive the success of CAR-T therapy against solid tumors.

Identification of three subtypes of triple-negative breast cancer with potential therapeutic implications

Background

Heterogeneity and lack of targeted therapies represent the two main impediments to precision treatment of triple-negative breast cancer (TNBC), and therefore, molecular subtyping and identification of therapeutic pathways are required to optimize medical care. The aim of the present study was to define robust TNBC subtypes with clinical relevance.

Methods

Gene expression profiling by means of DNA chips was conducted in an internal TNBC cohort composed of 238 patients. In addition, external data (n = 257), obtained by using the same DNA chip, were used for validation. Fuzzy clustering was followed by functional annotation of the clusters. Immunohistochemistry was used to confirm transcriptomics results: CD138 and CD20 were used to test for plasma cell and B lymphocyte infiltrations, respectively; MECA79 and CD31 for tertiary lymphoid structures; and UCHL1/PGP9.5 and S100 for neurogenesis.

Results

We identified three molecular clusters within TNBC: one molecular apocrine (C1) and two basal-like-enriched (C2 and C3). C2 presented pro-tumorigenic immune response (immune suppressive), high neurogenesis (nerve infiltration), and high biological aggressiveness. In contrast, C3 exhibited adaptive immune response associated with complete B cell differentiation that occurs in tertiary lymphoid structures, and immune checkpoint upregulation. External cohort subtyping by means of the same approach proved the robustness of these results. Furthermore, plasma cell and B lymphocyte infiltrates, tertiary lymphoid structures, and neurogenesis were validated at the protein levels by means of histological evaluation and immunohistochemistry.

Conclusion

Our work showed that TNBC can be subcategorized in three different subtypes characterized by marked biological features, some of which could be targeted by specific therapies.

Electronic supplementary material

The online version of this article (10.1186/s13058-019-1148-6) contains supplementary material, which is available to authorized users.

Phase I/II trial of pimasertib plus gemcitabine in patients with metastatic pancreatic cancer

The selective MEK1/2 inhibitor pimasertib has shown anti-tumour activity in a pancreatic tumour model. This phase I/II, two-part trial was conducted in patients with metastatic pancreatic adenocarcinoma (mPaCa) (NCT01016483). In the phase I part, oral pimasertib was given once daily discontinuously (5 days on/2 days off treatment) or twice daily continuously (n = 53) combined with weekly gemcitabine (1,000 mg/m2 ) in 28-day cycles to identify the recommended phase II dose (RP2D) of pimasertib. In the phase II part, patients were randomised to pimasertib (RP2D) or placebo plus weekly gemcitabine (n = 88) to investigate progression-free survival (PFS), overall survival (OS) and safety. The RP2D was determined to be 60 mg BID. PFS and OS outcomes did not indicate any treatment benefit for pimasertib over placebo in combination with gemcitabine (median PFS 3.7 and 2.8 months, respectively, HR = 0.91, 95% CI: 0.58-1.42: median OS 7.3 vs. 7.6 months, respectively). KRAS status did not influence PFS or OS. The incidence of grade ≥3 adverse events was 91.1% and 85.7% for pimasertib/gemcitabine and placebo/gemcitabine respectively, but there was a higher incidence of ocular events with pimasertib/gemcitabine (28.9% vs. 4.8% for placebo/gemcitabine). In conclusion, no clinical benefit was observed with first-line pimasertib plus gemcitabine compared with gemcitabine alone in patients with mPaCa.

Abstract CT123: A phase I study assessing the safety and clinical activity of multiple doses of a NKG2D-based CAR-T therapy, CYAD-01, administered concurrently with the neoadjuvant FOLFOX treatment in patients with potentially resectable liver metastases from colorectal cancer

We recently developed a novel chimeric antigen receptor (CAR) T-cell therapy, called CYAD-01 (a.k.a. NKR-2), incorporating the full-length human natural killer receptor NKG2D fused with the human CD3 zeta signaling domain, which associates with the adaptor molecule DAP10 to provide co-stimulatory signal upon ligand binding. CYAD-01 is currently evaluated in the ongoing THINK study (NCT03018405) without preconditioning therapy in both hematological and solid indications. Classical CAR-Ts has yet to demonstrate positive results in the context of solid tumors. Underlying reasons for this reduced clinical activity include the need to extravasate from the peripheral circulation, infiltrate into the tumor and overcome the hostile immune suppressive tumor microenvironment (TME) to deliver anti-tumor effector responses. To address the challenge related to the immunosuppressive TME, the SHRINK trial (Standard cHemotherapy Regimen and Immunotherapy with NKR-2) has been developed to assess the safety and clinical activity of multiple infusion CYAD-01 treatment (every 2 weeks x 3 infusions) in patients undergoing standard-of-care FOLFOX (Folinic acid, Fluorouracil (5-FU) and Oxaliplatin) chemotherapy, as neoadjuvant treatment, for the treatment of colorectal metastatic disease with potentially resectable metastases (NCT03310008). The FOLFOX treatment is given every two weeks for six cycles and CYAD-01 cells are infused shortly after chemotherapy on cycles 3, 4 and 5. This concurrent administration of chemotherapy and CYAD-01 treatments would not only (i) favor infiltration into the immunosuppressive TME due to the effect of chemotherapy on TME and cancer cells but also (ii) provide an opportunity for the CYAD-01 cells to better engraft due to the lymphodepletion induced by the standard chemotherapy administration, and likely (iii) increase the NKG2D ligand expression in tumor tissues targeted by CYAD-01, even in patients presenting heterogeneity and/or low ligand expression. The study contains two consecutive segments. The dose escalation segment will enroll 9 patients and will evaluate 3 dose levels of CYAD-01 (1x108, 3x108 and 1x109 CYAD-01 per injection) following a 3+3 design. The expansion segment will then enroll 21 additional patients to further evaluate the safety and potential signs of activity of the CYAD-01 therapy when administered concurrently with chemotherapy. Peripheral blood samples, as well as tumor biopsies from patients at baseline and at resection, will be collected to determine, among others, CYAD-01 persistence, NKG2D ligand expression and systemic cytokine levels in peripheral blood post-infusion.

Citation Format: Caroline Lonez, Alain Hendlisz, Leila Shaza, Philippe Aftimos, Ahmad Awada, Jean-Pascal H. Machiels, Marc Van Den Eynde, Jean-Luc Canon, Javier Carrasco, Bikash Verma, David E. Gilham, Frédéric F. Lehmann. A phase I study assessing the safety and clinical activity of multiple doses of a NKG2D-based CAR-T therapy, CYAD-01, administered concurrently with the neoadjuvant FOLFOX treatment in patients with potentially resectable liver metastases from colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT123.

Final analysis of the randomised PEAK trial: overall survival and tumour responses during first-line treatment with mFOLFOX6 plus either panitumumab or bevacizumab in patients with metastatic colorectal carcinoma

PURPOSE

To report planned final overall (OS) and progression-free survival (PFS) analyses from the phase II PEAK trial (NCT00819780).

METHODS

Patients with previously untreated, KRAS exon 2 wild-type (WT) metastatic colorectal cancer (mCRC) were randomised to mFOLFOX6 plus panitumumab or bevacizumab. The primary endpoint was PFS; secondary endpoints included OS, objective response rate, duration of response (DoR), time to response, resection and safety. Treatment effect by tumour RAS status was a prespecified objective. Exploratory analyses included early tumour shrinkage (ETS) and depth of response (DpR).

RESULTS

One hundred seventy patients had RAS WT and 156 had RAS WT/BRAF WT mCRC. Median PFS was longer for panitumumab versus bevacizumab in the RAS WT (12.8 vs 10.1 months; hazard ratio (HR) = 0.68 [95% confidence intervals (CI) = 0.48-0.96]; p = 0.029) and RAS WT/BRAF WT (13.1 vs 10.1 months; HR = 0.61 [95% CI = 0.42-0.88]; p = 0.0075) populations. Median OS (68% OS events) for panitumumab versus bevacizumab was 36.9 versus 28.9 months (HR = 0.76 [95% CI = 0.53-1.11]; p = 0.15) and 41.3 versus 28.9 months (HR = 0.70 [95% CI = 0.48-1.04]; p = 0.08), in the RAS WT and RAS WT/BRAF WT populations, respectively. Median DoR (11.4 vs 9.0 months; HR = 0.59 [95% CI = 0.39-0.88]; p = 0.011) and DpR (65.0 vs 46.3%; p = 0.0018) were improved in the panitumumab group. More panitumumab patients experienced ≥30% ETS at week 8 (64 vs 45%; p = 0.052); ETS was associated with improved PFS/OS. No new safety signals occurred.

CONCLUSIONS

First-line panitumumab + mFOLFOX6 increases PFS versus bevacizumab + mFOLFOX6 in patients with RAS WT mCRC.

The MicroRNA miR-210 Is Expressed by Cancer Cells but Also by the Tumor Microenvironment in Triple-Negative Breast Cancer

The triple-negative breast cancer (TNBC) subtype occurs in about 15% of breast cancer and is an aggressive subtype of breast cancer with poor outcome. Furthermore, treatment of patients with TNBC is more challenging due to the heterogeneity of the disease and the absence of well-defined molecular targets. Microribonucleic acid (RNA) represents a new class of biomarkers that are frequently dysregulated in cancer. It has been described that the microRNA miR-210 is highly expressed in TNBC, and its overexpression had been linked to poor prognosis. TNBC are often infiltrated by immune cells that play a key role in cancer progression. The techniques traditionally used to analyze miR-210 expression such as next generation sequencing or quantitative real-time polymerase chain reaction (PCR) do not allow the precise identification of the cellular subtype expressing the microRNA. In this study, we have analyzed miR-210 expression by in situ hybridization in TNBC. The miR-210 signal was detected in tumor cells, but also in the tumor microenvironment, in a region positive for the pan-leucocyte marker CD45-LCA. Taken together, our results demonstrate that miR-210 is expressed in tumor cells but also in the tumor microenvironment. Our results also highlight the utility of using complementary approaches to take into account the cellular context of microRNA expression.

Tumor lysis syndrome following trastuzumab and pertuzumab for metastatic breast cancer: a case report

Background

Tumor lysis syndrome is a rare and potentially fatal complication of oncologic treatments, especially in solid tumors. To the best of our knowledge, tumor lysis syndrome has never been reported after trastuzumab and pertuzumab combination therapy. Knowledge of risk factors and active prevention proceedings is of utmost importance to avoid fatal outcomes.

Case presentation

We present the case of a chemo-naive 58-year-old Belgian woman developing hypovolemic shock and multiple organ failure due to tumor lysis syndrome after a single dose of trastuzumab and pertuzumab in the context of the treatment of a metastatic breast cancer and resulting in fatal outcome despite optimal management.

Conclusions

Considering that targeted cancer therapies become increasingly effective, oncologists should be extremely cautious when treating patients at high risk of tumor lysis syndrome, even if they are not treated with cytotoxic chemotherapy, and determine appropriate prophylaxis.

Prospective Evaluation of First-Line Erlotinib in Advanced Non-Small Cell Lung Cancer (NSCLC) Carrying an Activating EGFR Mutation: A Multicenter Academic Phase II Study in Caucasian Patients (FIELT)

Introduction

Epidermal Growth Factor Receptor (EGFR) tyrosine kinase inhibition is the preferred first-line treatment of advanced adenocarcinoma of the lung that harbors EGFR activating tyrosine kinase domain mutations. Most data available pertain to Asian populations in which such mutations are more prevalent. We report on the long-term results of first-line treatment with erlotinib in Caucasian patients with advanced adenocarcinoma of the lung that have a somatic EGFR mutation in their tumor.

Methods

Multicenter academic prospective phase II study with erlotinib in patients with an activating EGFR tyrosine kinase (TK) domain somatic mutation (any exon encoding the kinase domain) in the tumor and no prior treatment for their advanced disease.

Results

Phenotypic preselecting of 229 patients led to a high EGFR mutation detection rate of 24% of which 46 patients were included in the phase II study. With a progression free survival (PFS) of 81% at three months the study met its primary endpoint for presumed superiority over chemotherapy. With an overall median PFS of 11 months and a median overall survival (OS) of 23 months, the results compare favorably with results obtained in randomized studies using TKI in first line in EGFR mutation positive adenocarcinoma of the lung.

Conclusion

The present study reinforces the use of EGFR tyrosine kinase inhibition (TKI) as a first line treatment of choice for advanced adenocarcinoma of the lung carrying an activating EGFR mutation. The mutation rate in preselected Caucasian patients is higher than previously reported. Issues relevant for clinical practice are discussed.

Trial Registration

ClinicalTrials.gov NCT00339586

Phase II study of afatinib, an irreversible ErbB family blocker, in demographically and genotypically defined lung adenocarcinoma

OBJECTIVES

Afatinib, an oral irreversible ErbB family blocker, has demonstrated efficacy in patients with epidermal growth factor receptor (EGFR) mutation-positive advanced lung adenocarcinoma. Other potential biomarkers predicting response to afatinib, such as human epidermal growth factor receptor-2 (HER2) mutations and EGFR gene amplification, have not been validated yet. This phase II study investigated whether afatinib conferred clinical benefit in cohorts of adenocarcinoma patients with: (1) EGFR mutation and failing on erlotinib/gefitinib; or (2) increased copy number of EGFR by fluorescence in situ hybridization (FISH); or (3) HER2 mutation.

MATERIALS AND METHODS

Patients started daily afatinib 50mg monotherapy. Upon disease progression, patients could continue, at the investigator's discretion, afatinib (40mg) with the addition of paclitaxel (80mg/m(2) weekly for 3 weeks/4-week cycle). Endpoints included confirmed objective response (OR), progression-free survival (PFS), disease control, and safety.

RESULTS

Of 41 patients treated (cohort 1: n=32; cohort 2: n=2; cohort 3: n=7), 33 received afatinib monotherapy; eight subsequently received afatinib plus paclitaxel. With afatinib monotherapy, one patient achieved a confirmed OR (partial response [PR]; cohort 2). Two further patients achieved unconfirmed PRs (one each in cohort 1 and cohort 3). Disease control was achieved by 17/32 (53%), 2/2 (100%) and 5/7 (71%) patients in cohorts 1, 2 and 3, respectively. In patients receiving combination therapy (median PFS: 6.7 weeks), one (cohort 3) had confirmed PR of 41.9 weeks. The most common afatinib-related adverse events were diarrhea (95%) and rash/acne (80%).

CONCLUSION

Afatinib demonstrated signs of clinical activity in heavily pretreated patients with activating HER2 or EGFR mutations or EGFR FISH-positive tumors.

Phase II randomized trial of MEK inhibitor pimasertib or placebo combined with gemcitabine in the first-line treatment of metastatic pancreatic cancer

344

Background: In metastatic pancreatic cancer (mPaCa), KRAS mutations lead to constitutive activation of the MAPK pathway in the vast majority of cases. Pimasertib (Pim) is a selective, non-competitive MEK 1/2 inhibitor with potent antitumor activity in preclinical models with constitutive MAPK activation. Methods: Following a phase I, dose-finding part to the trial, 88 patients (pts) with mPaCa were randomized 1:1 to receive Pim 60 mg BID (A, 44 pts) or placebo (B, 44 pts) in combination with weekly gemcitabine (Gem) 1000 mg/m2(7 of 8 wks in cycle 1, then 3 of 4 wks in subsequent cycles), in a phase II setting (NCT01016483). The primary endpoint was progression-free survival (PFS). Response rate (RR), overall survival (OS) and safety were secondary endpoints. Biomarker analysis was an exploratory endpoint. Results: Pt characteristics were balanced (median age 63.5 yrs, males 56%, stage IV at initial diagnosis 75%) except for PS 0, which was more frequent in arm A (59 vs 41%). Time on treatment was longer in arm B (10.6 vs 8.0 wks). A higher proportion of pts in arm A discontinued treatment during the first 4 wks (31 vs 19%), predominantly due to adverse events (AEs) and PD. Median PFS was 3.7 mo in arm A and 2.8 mo in arm B (HR=0.883, 95% CI: 0.549–1.42; p=0.608). No statistically significant differences were observed between arms for OS (median 7.3 mo in arm A vs 8.3 mo in arm B) and RECIST 1.0 RR (9.1% in both arms). Grade ≥3 thrombocytopenia (20.0 vs 0%), vomiting (15.6 vs 4.8%), fatigue (15.6 vs 7.1%), stomatitis (13.3 vs 0%) and diarrhea (11.1 vs 2.4%) were more common in arm A. Typical allosteric MEK inhibitor-related AEs, such as all grade retinal detachment (24.4%) and creatine phosphokinase elevation (20.0%), were observed almost exclusively in arm A. KRAS mutational status did not influence PFS or OS. Conclusions: The primary study endpoint was not met; secondary endpoints did not suggest clinically meaningful differences between arms, except for selected toxicities observed more frequently with the combination of Gem and Pim. The outcome does not support further development of this combination in the first-line setting in mPaCa. Pim is currently in development in other solid tumors. Clinical trial information: NCT01016483.

Identification by array comparative genomic hybridization of a new amplicon on chromosome 17q highly recurrent in BRCA1 mutated triple negative breast cancer

INTRODUCTION

Triple Negative Breast Cancers (TNBC) represent about 12% to 20% of all breast cancers (BC) and have a worse outcome compared to other BC subtypes. TNBC often show a deficiency in DNA double-strand break repair mechanisms. This is generally related to the inactivation of a repair enzymatic complex involving BRCA1 caused either by genetic mutations, epigenetic modifications or by post-transcriptional regulations. The identification of new molecular biomarkers that would allow the rapid identification of BC presenting a BRCA1 deficiency could be useful to select patients who could benefit from PARP inhibitors, alkylating agents or platinum-based chemotherapy.

METHODS

Genomic DNA from 131 formalin-fixed paraffin-embedded (FFPE) tumors (luminal A and B, HER2+ and triple negative BC) with known BRCA1 mutation status or unscreened for BRCA1 mutation were analysed by array Comparative Genomic Hybridization (array CGH). One highly significant and recurrent gain in the 17q25.3 genomic region was analysed by fluorescent in situ hybridization (FISH). Expression of the genes of the 17q25.3 amplicon was studied using customized Taqman low density arrays and single Taqman assays (Applied Biosystems).

RESULTS

We identified by array CGH and confirmed by FISH a gain in the 17q25.3 genomic region in 90% of the BRCA1 mutated tumors. This chromosomal gain was present in only 28.6% of the BRCA1 non-mutated TNBC, 26.7% of the unscreened TNBC, 13.6% of the luminal B, 19.0% of the HER2+ and 0% of the luminal A breast cancers. The 17q25.3 gain was also detected in 50% of the TNBC with BRCA1 promoter methylation. Interestingly, BRCA1 promoter methylation was never detected in BRCA1 mutated BC. Gene expression analyses of the 17q25.3 sub-region showed a significant over-expression of 17 genes in BRCA1 mutated TNBC (n = 15) as compared to the BRCA1 non mutated TNBC (n = 13).

CONCLUSIONS

In this study, we have identified by array CGH and confirmed by FISH a recurrent gain in 17q25.3 significantly associated to BRCA1 mutated TNBC. Up-regulated genes in the 17q25.3 amplicon might represent potential therapeutic targets and warrant further investigation.

Final results from PRIME: randomized phase III study of panitumumab with FOLFOX4 for first-line treatment of metastatic colorectal cancer

BACKGROUND

The Panitumumab Randomized trial In combination with chemotherapy for Metastatic colorectal cancer to determine Efficacy (PRIME) demonstrated that panitumumab-FOLFOX4 significantly improved progression-free survival (PFS) versus FOLFOX4 as first-line treatment of wild-type (WT) KRAS metastatic colorectal cancer (mCRC), the primary end point of the study.

PATIENTS AND METHODS

Patients were randomized 1:1 to panitumumab 6.0 mg/kg every 2 weeks + FOLFOX4 (arm 1) or FOLFOX4 (arm 2). This prespecified final descriptive analysis of efficacy and safety was planned for 30 months after the last patient was enrolled.

RESULTS

A total of 1183 patients were randomized. Median PFS for WT KRAS mCRC was 10.0 months [95% confidence interval (CI) 9.3-11.4 months] for arm 1 and 8.6 months (95% CI 7.5-9.5 months) for arm 2; hazard ratio (HR) = 0.80; 95% CI 0.67-0.95; P = 0.01. Median overall survival (OS) for WT KRAS mCRC was 23.9 months (95% CI 20.3-27.7 months) for arm 1 and 19.7 months (95% CI 17.6-22.7 months) for arm 2; HR = 0.88; 95% CI 0.73-1.06; P = 0.17 (68% OS events). An exploratory analysis of updated survival (>80% OS events) was carried out which demonstrated improvement in OS; HR = 0.83; 95% CI 0.70-0.98; P = 0.03 for WT KRAS mCRC. The adverse event profile was consistent with the primary analysis.

CONCLUSIONS

In WT KRAS mCRC, PFS was improved, objective response was higher, and there was a trend toward improved OS with panitumumab-FOLFOX4, with significant improvement in OS observed in an updated analysis of survival in patients with WT KRAS mCRC treated with panitumumab + FOLFOX4 versus FOLFOX4 alone (P = 0.03). These data support a positive benefit-risk profile for panitumumab-FOLFOX4 for patients with previously untreated WT KRAS mCRC. KRAS testing is critical to select appropriate patients for treatment with panitumumab.

PEAK: a randomized, multicenter phase II study of panitumumab plus modified fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) or bevacizumab plus mFOLFOX6 in patients with previously untreated, unresectable, wild-type KRAS exon 2 metastatic colorectal cancer

PURPOSE

To evaluate panitumumab plus modified fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) or bevacizumab plus mFOLFOX6 in patients with previously untreated wild-type (WT) KRAS exon 2 (codons 12 and 13) metastatic colorectal cancer (mCRC). A prespecified secondary objective was to assess treatment effects in an extended RAS analysis that included exons 2, 3, and 4 of KRAS and NRAS.

PATIENTS AND METHODS

Patients with WT KRAS exon 2 tumors were randomly assigned at a one-to-one ratio to panitumumab plus mFOLFOX6 or bevacizumab plus mFOLFOX6. The primary end point was progression-free survival (PFS); secondary end points included overall survival (OS) and safety.

RESULTS

Of 285 randomly assigned patients, 278 received treatment. In the WT KRAS exon 2 intent-to-treat group, PFS was similar between arms (hazard ratio [HR], 0.87; 95% CI, 0.65 to 1.17; P = .353). Median OS was 34.2 and 24.3 months in the panitumumab and bevacizumab arms, respectively (HR, 0.62; 95% CI, 0.44 to 0.89; P = .009). In the WT RAS subgroup (WT exons 2, 3, and 4 of KRAS and NRAS), PFS favored the panitumumab arm (HR, 0.65; 95% CI, 0.44 to 0.96; P = .029). Median OS was 41.3 and 28.9 months (HR, 0.63; 95% CI, 0.39 to 1.02; P = .058) in the panitumumab and bevacizumab arms, respectively. Treatment discontinuation rates because of adverse events were similar between arms.

CONCLUSION

PFS was similar and OS was improved with panitumumab relative to bevacizumab when combined with mFOLFOX6 in patients with WT KRAS exon 2 tumors. Patients with WT RAS tumors seemed to experience more clinical benefit with anti-epidermal growth factor receptor therapy.

PEAK: a randomized, multicenter phase II study of panitumumab plus modified fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) or bevacizumab plus mFOLFOX6 in patients with previously untreated, unresectable, wild-type KRAS exon 2 metastatic colorectal cancer

PURPOSE

To evaluate panitumumab plus modified fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) or bevacizumab plus mFOLFOX6 in patients with previously untreated wild-type (WT) KRAS exon 2 (codons 12 and 13) metastatic colorectal cancer (mCRC). A prespecified secondary objective was to assess treatment effects in an extended RAS analysis that included exons 2, 3, and 4 of KRAS and NRAS.

PATIENTS AND METHODS

Patients with WT KRAS exon 2 tumors were randomly assigned at a one-to-one ratio to panitumumab plus mFOLFOX6 or bevacizumab plus mFOLFOX6. The primary end point was progression-free survival (PFS); secondary end points included overall survival (OS) and safety.

RESULTS

Of 285 randomly assigned patients, 278 received treatment. In the WT KRAS exon 2 intent-to-treat group, PFS was similar between arms (hazard ratio [HR], 0.87; 95% CI, 0.65 to 1.17; P = .353). Median OS was 34.2 and 24.3 months in the panitumumab and bevacizumab arms, respectively (HR, 0.62; 95% CI, 0.44 to 0.89; P = .009). In the WT RAS subgroup (WT exons 2, 3, and 4 of KRAS and NRAS), PFS favored the panitumumab arm (HR, 0.65; 95% CI, 0.44 to 0.96; P = .029). Median OS was 41.3 and 28.9 months (HR, 0.63; 95% CI, 0.39 to 1.02; P = .058) in the panitumumab and bevacizumab arms, respectively. Treatment discontinuation rates because of adverse events were similar between arms.

CONCLUSION

PFS was similar and OS was improved with panitumumab relative to bevacizumab when combined with mFOLFOX6 in patients with WT KRAS exon 2 tumors. Patients with WT RAS tumors seemed to experience more clinical benefit with anti-epidermal growth factor receptor therapy.

Neutrophil:lymphocyte ratio and intraoperative use of ketorolac or diclofenac are prognostic factors in different cohorts of patients undergoing breast, lung, and kidney cancer surgery

BACKGROUND

Inflammation is associated with a worse outcome in cancer and neutrophil:lymphocyte ratio (NLR) is a strong prognostic value. In cancer, nonsteroidal anti-inflammatory drugs (NSAIDs) could be of interest. We investigated the prognostic significance of NLR and the impact of intraoperative NSAIDs in cancer surgeries.

METHODS

We performed an observational study in early breast, kidney, and lung cancers (357, 227, and 255 patients) with uni- and multivariate analyses (Cox model).

RESULTS

In breast cancer (Centre 1), NLR ≥ 4 is associated with a higher risk of relapse (hazards ratio (HR) = 2.41; 95 % confidence interval (CI) 1.01-5.76; P = 0.048). In breast cancer (Centre 2), NLR ≥ 3 is associated with a higher risk of relapse (HR = 4.6; 95 % CI 1.09-19.1; P = 0.04) and higher mortality (HR = 4.0; 95 % CI 1.12-14.3; P = 0.03). In kidney cancer, NLR ≥ 5 is associated with a higher risk of relapse (HR = 1.63; 95 % CI 1.00-2.66; P = 0.05) and higher mortality (HR = 1.67; 95 % CI 1.0-2.81; P = 0.05). In lung cancer, NLR ≥ 5 is associated with higher mortality (HR = 1.45; 95 % CI 1.02-2.06; P = 0.04). The intraoperative use of NSAIDs in breast cancer patients (Centre 1) is associated with a reduced recurrence rate (HR = 0.17; 95 % CI 0.04-0.43; P = 0.0002) and a lower mortality (HR = 0.25; 95 % CI 1.08-0.75; P = 0.01). NSAIDs use at the beginning of the surgery is independently associated with a lower metastases risk after lung cancer surgery (HR = 0.16; 95 % CI 0.04-0.63; P = 0.009). Ketorolac use is independently associated with longer survival (HR = 0.55; 95 % CI 0.31-0.95; P = 0.03).

CONCLUSIONS

In these cohorts, these analyses show that NLR is a strong perioperative prognosis factor for breast, lung, and kidney cancers. In this context, intraoperative NSAIDs administration could be associated with a better outcome.

Correlation of HER2, FCGR2A, and FCGR3A gene polymorphisms with trastuzumab related cardiac toxicity and efficacy in a subgroup of patients from UNICANCER-PACS 04 trial

The purpose of this study was to investigate, in the context of a prospective node-positive-breast cancer trial HER2 containing-regimen (UNICANCER-PACS 04 trial), the predictive value of HER2, FCGRIIA, and FCGRIIIA gene polymorphisms for cardiac toxicity and efficacy of trastuzumab. We analyzed HER2-I655V, FCGR2A-H131R, and FCGR3A-V158F single nucleotide polymorphisms in patients in adjuvant setting treated by six courses of either fluorouracil 500 mg/m(2), epirubicin 100 mg/m(2) and cyclophosphamide 500 mg/m(2), or epirubicin 75 mg/m(2) and docetaxel 75 mg/m(2) every 3 weeks then randomly assigned, in case of HER2 overexpressing tumor, to either trastuzumab for 1 year or nothing. Left ventricular ejection fraction and clinical examination were monitored in each patient, seven times throughout the study to detect congestive heart failure or asymptomatic subclinical cardiac toxicity. All genotypes were analyzed in relation to cardiac toxicity, EFS, and OS. One hundred and thirty-two HER2-positive breast cancer patients were analyzed. The HER2-I655V genotype was significantly associated with cardiac toxicity (p = 0.025). The FCGR2A-131 H/H genotype was significantly correlated with a shorter EFS (p = 0.027). The FCGR3A-158 V/V genotype was not correlated with EFS nor OS. These results might be useful in making a treatment choice of HER2 blockers in adjuvant setting by with an increase in efficacy and decrease in toxicity.

Phase II study of afatinib, an irreversible ErbB family blocker, in demographically and genotypically defined non-small cell lung cancer (NSCLC) patients

8063

Background: EGFR mutation+ (M+) NSCLC pts have an improved response to EGFR TKIs vs non-M+ pts. Data on EGFR FISH+ (gene amplified) and HER2 M+ pts are, however, limited. Afatinib is an irreversible ErbB Family Blocker with efficacy in Ph II/III trials in EGFR M+ NSCLC. This exploratory, open-label trial assessed afatinib in 3 genotypically and demographically defined NSCLC groups. Methods: Never/ex-smokers with stage IIIB/IV lung adenocarcinoma with EGFR M+ tumors who had failed prior EGFR TKIs, HER2 M+ tumors independent of prior therapy, or EGFR FISH+ tumors who received ≤3 prior chemotherapies were enrolled. Afatinib 50 mg qd was administered until disease progression or intolerable adverse events. Tumor assessments (RECIST 1.0) were performed every 8 wks. Pts who progressed on afatinib but experienced clinical benefit could continue treatment with afatinib 40 mg qd + paclitaxel 80 mg/m² qw on days 1, 8 and 15 every 28-day cycle. Primary endpoint: Confirmed objective response. Results: 41 pts were treated: 63% female; median age 63 yrs; 68% never smokers; 32% ex-smokers. 33 pts received afatinib monotherapy only; 8 pts received afatinib followed by afatinib/paclitaxel combination therapy. 78% (n=32) of pts were EGFR M+, 5% (n=2) were EGFR FISH+ and 17% (n=7) were HER2 M+. For afatinib monotherapy, 1 confirmed partial response (PR) was observed (EGFR FISH+), stable disease (SD) was seen in 5/7 HER2 M+, 2/2 EGFR FISH+ and 17/32 EGFR M+ pts, and overall disease control (DC) rate was 59% (n=24); mean duration of DC was 26 wks.Median PFS was 16 wks (17 wks in HER2 M+ pts). Of 8 afatinib/paclitaxel-treated pts, 1 had a confirmed PR and 2 had SD; median PFS was 7 wks. Most frequently reported drug-related AEs in afatinib monotherapy pts were diarrhea (n=39; grade ≥3 n=13), rash/acne (n=33; grade ≥3 n=4) and stomatitis (n=19; grade ≥3 n=2). In the combination arm these were diarrhea (n=4; grade ≥3 n=1) and nausea (n=3; grade ≥3 n=0). Conclusions: Efficacy of afatinib in EGFR M+ NSCLC pts has been established in previous trials. Novel activity of afatinib in HER2 M+ and EGFR FISH+ NSCLC pts has been demonstrated here, with a manageable safety profile of afatinib in the overall population. Clinical trial information: NCT00730925.

Overall survival (OS) analysis from PRIME: Randomized phase III study of panitumumab (pmab) with FOLFOX4 for first-line metastatic colorectal cancer (mCRC)

3620

Background: The primary and final analyses of PRIME demonstrated that pmab + FOLFOX4 significantly improved progression-free survival (PFS) vs FOLFOX4 alone for first-line treatment of patients (pts) with wild-type (WT) KRAS exon 2 mCRC. Methods: Pts were randomized 1:1 to pmab 6.0 mg/kg every 2 weeks + FOLFOX4 or FOLFOX4 alone and had no prior chemotherapy for mCRC, ECOG performance status ≤ 2, and tumor tissue for biomarker testing. The primary endpoint was PFS by central assessment. Secondary endpoints included OS, objective response rate, and safety. KRAS exon 2 tumor status was determined by a blinded central lab prior to the primary analysis. This exploratory analysis of updated survival (>80% OS events) estimated the treatment effect of pmab + FOLFOX4 compared with FOLFOX4 alone on OS by KRAS exon 2 status. Previous analyses in pts with WT KRAS exon 2 tumor status reported OS with an event rate of 54% of pts in the primary analysis and 68% of pts in the final analysis. Results: 1183 pts were randomized and received treatment: 593 pts in the pmab + FOLFOX4 arm and 590 pts in the FOLFOX4 alone arm. The KRAS exon 2 ascertainment rate was 93%, consistent with the primary analysis. 535/656 pts (82%) with WT KRAS exon 2 mCRC had an OS event at the time of this analysis. Results are shown (Table). Conclusions: In this updated analysis, an improvement in OS was observed in pts with WT KRAS exon 2 mCRC treated with pmab + FOLFOX4 vs FOLFOX4 alone (p = 0.03). Median OS was reduced in pts with mutant (MT) KRAS mCRC (p = 0.16) and is consistent with previous analyses. Updated efficacy and safety results will be presented. KRAS testing is critical to select appropriate pts with mCRC for treatment with pmab. Clinical trial information: NCT00364013. [Table: see text]