Fulvestrant and everolimus efficacy after CDK4/6 inhibitor: a prospective study with circulating tumor DNA analysis

In a prospective study (NCT02866149), we assessed the efficacy of fulvestrant and everolimus in CDK4/6i pre-treated mBC patients and circulating tumor DNA (ctDNA) changes throughout therapy. Patients treated with fulvestrant and everolimus had their ctDNA assessed at baseline, after 3-5 weeks and at disease progression. Somatic mutations were identified in archived tumor tissues by targeted NGS and tracked in cell-free DNA by droplet digital PCR. ctDNA detection was then associated with clinicopathological characteristics and patients' progression-free survival (PFS), overall survival (OS) and best overall response (BOR). In the 57 included patients, median PFS and OS were 6.8 (95%CI [5.03-11.5]) and 38.2 (95%CI [30.0-not reached]) months, respectively. In 47 response-evaluable patients, BOR was a partial response or stable disease in 15 (31.9%) and 11 (23.4%) patients, respectively. Among patients with trackable somatic mutation and available plasma sample, N = 33/47 (70.2%) and N = 19/36 (52.8%) had ctDNA detected at baseline and at 3 weeks, respectively. ctDNA detection at baseline and PIK3CA mutation had an adverse prognostic impact on PFS and OS in multivariate analysis. This prospective cohort study documents the efficacy of fulvestrant and everolimus in CDK4/6i-pretreated ER + /HER2- mBC and highlights the clinical validity of early ctDNA changes as pharmacodynamic biomarker.

Tumor mutational burden assessment and standardized bioinformatics approach using custom NGS panels in clinical routine

BACKGROUND

High tumor mutational burden (TMB) was reported to predict the efficacy of immune checkpoint inhibitors (ICIs). Pembrolizumab, an anti-PD-1, received FDA-approval for the treatment of unresectable/metastatic tumors with high TMB as determined by the FoundationOne®CDx test. It remains to be determined how TMB can also be calculated using other tests.

RESULTS

FFPE/frozen tumor samples from various origins were sequenced in the frame of the Institut Curie (IC) Molecular Tumor Board using an in-house next-generation sequencing (NGS) panel. A TMB calculation method was developed at IC (IC algorithm) and compared to the FoundationOne® (FO) algorithm. Using IC algorithm, an optimal 10% variant allele frequency (VAF) cut-off was established for TMB evaluation on FFPE samples, compared to 5% on frozen samples. The median TMB score for MSS/POLE WT tumors was 8.8 mut/Mb versus 45 mut/Mb for MSI/POLE-mutated tumors. When focusing on MSS/POLE WT tumor samples, the highest median TMB scores were observed in lymphoma, lung, endometrial, and cervical cancers. After biological manual curation of these cases, 21% of them could be reclassified as MSI/POLE tumors and considered as "true TMB high." Higher TMB values were obtained using FO algorithm on FFPE samples compared to IC algorithm (40 mut/Mb [10-3927] versus 8.2 mut/Mb [2.5-897], p < 0.001).

CONCLUSIONS

We herein propose a TMB calculation method and a bioinformatics tool that is customizable to different NGS panels and sample types. We were not able to retrieve TMB values from FO algorithm using our own algorithm and NGS panel.

First-Line Ipatasertib, Atezolizumab, and Taxane Triplet for Metastatic Triple-Negative Breast Cancer: Clinical and Biomarker Results

PURPOSE

To evaluate a triplet regimen combining immune checkpoint blockade, AKT pathway inhibition, and (nab-) paclitaxel as first-line therapy for locally advanced/metastatic triple-negative breast cancer (mTNBC).

PATIENTS AND METHODS

The single-arm CO40151 phase Ib study (NCT03800836), the single-arm signal-seeking cohort of IPATunity130 (NCT03337724), and the randomized phase III IPATunity170 trial (NCT04177108) enrolled patients with previously untreated mTNBC. Triplet therapy comprised intravenous atezolizumab 840 mg (days 1 and 15), oral ipatasertib 400 mg/day (days 1-21), and intravenous paclitaxel 80 mg/m2 (or nab-paclitaxel 100 mg/m2; days 1, 8, and 15) every 28 days. Exploratory translational research aimed to elucidate mechanisms and molecular markers of sensitivity and resistance.

RESULTS

Among 317 patients treated with the triplet, efficacy ranged across studies as follows: median progression-free survival (PFS) 5.4 to 7.4 months, objective response rate 44% to 63%, median duration of response 5.6 to 11.1 months, and median overall survival 15.7 to 28.3 months. The safety profile was consistent with the known toxicities of each agent. Grade ≥3 adverse events were more frequent with the triplet than with doublets or single-agent paclitaxel. Patients with PFS >10 months were characterized by NF1, CCND3, and PIK3CA alterations and increased immune pathway activity. PFS <5 months was associated with CDKN2A/CDKN2B/MTAP alterations and lower predicted phosphorylated AKT-S473 levels.

CONCLUSIONS

In patients with mTNBC receiving an ipatasertib/atezolizumab/taxane triplet regimen, molecular characteristics may identify those with particularly favorable or unfavorable outcomes, potentially guiding future research efforts.

Accelerated subsequent lung cancer after post-operative radiotherapy for breast cancer

BACKGROUND

Post-operative whole breast radiotherapy for breast cancer (BC) may increase the risk of subsequent lung cancer (LC). The impact of radiotherapy intensification (boost) has not been specifically explored in this context. We investigated the role of radiation modalities on the development of subsequent LC among our patients treated by radiotherapy for localized BC.

METHODS

All patients with a diagnosis of LC between 2000 and 2020 with a history of prior localized BC treated by surgery and post-operative radiotherapy were retrospectively reviewed. Primary endpoint was time to first diagnosis of LC after BC treatment with radiotherapy (RT).

RESULTS

From 98 patients who developed subsequent LC after primary BC treated with post-operative RT, 38% of patients (n = 37) received an additional RT boost, and 46% (n = 45) received hormonal treatment post radiation. A total of 61% (n = 60) were smokers. With regards to LC characteristics, adenocarcinoma was the most frequent histology (68%, n = 66); 36% (n = 35) harbored at least 1 molecular alteration, 57% (n = 20) of them being amenable to targeted therapy. Median time to first diagnosis of LC was 6 years [1.7-28.4 yrs] in the whole cohort. In the subgroup of patients treated with boost this time was reduced to 4 years [1.8-20.8 years] compared to 8 years for patients without boost [1.7-28.4 yrs] (p = 0.007). Boost, smoking usage, endocrine therapy, and age <50 yrs old at BC radiation remained independent factors associated with shorter time to first diagnosis of LC after BC treatment.

DISCUSSION

We report for the first time the potential impact of boost -part of BC radiation treatment- for BC on the risk of subsequent LC. The impact of low dose radiation on lung parenchyma could explain this phenomenon, but the underlying physiopathology is still under investigation. This work highlights the need for clinicians to identify patients at risk of developing faster subsequent thoracic malignancy after BC radiation, for implementing personalized surveillance.

Abstract P5-02-19: ctDNA as dynamic marker of response to fulvestrant and everolimus in CDK4/6 inhibitor-pretreated ER+ HER2- metastatic breast cancer patients: a prospective study

ctDNA as dynamic marker of response to fulvestrant and everolimus in CDK4/6 inhibitor-pretreated ER+ HER2- metastatic breast cancer patients: a prospective study. Background The combination of fulvestrant with everolimus is recognized by NCCN and ESMO guidelines as a valid second line treatment option for ER+ HER2- metastatic breast cancer (mBC), upon progression on CDK4/6 inhibitor. The underlying evidence consists in a single randomized phase 2 trial (PrE0102, JCO 2018), in which N=66 patients allocated to fulvestrant and everolimus achieved a median PFS of 10.3 months (95%CI [7.6-13.8]). However, none of PrE0102 patients were pre-treated with CDK4/6 inhibitors. We set up a prospective study to document the PFS achieved by fulvestrant and everolimus in the pre-treated patients and investigated the clinical validity of ctDNA early changes as pharmacodynamic marker. Methods Eligible patients had ER+ HER2- mBC and had to be pre-treated by CDK4/6 inhibitor. Upon the signature of informed consent, patients were enrolled in the prospective observational ALCINA study (NCT02866149) and had their blood drawn at baseline (prior to treatment start), after 1 month on treatment, at first radiological assessment (3-4 months) and at disease progression. DNA from archived tumor tissue sample (or, when missing, from plasma obtained at baseline) was subjected to a large panel next generation sequencing. ctDNA levels were then assessed on the matched serial plasma samples by targeting the identified somatic mutation(s) with droplet digital PCR (ddPCR). Associations between clinicopathological characteristics, ctDNA levels and prospectively registered patient outcomes (PFS and OS) were then analyzed. Results Fifty-seven patients have been included, with a median age of 56.8 years. N=30 (52.6%) patients had ≥3 metastatic sites and N=34 (59.6%) had visceral metastases. Most patients (N=48, 84.2%) had only one prior line of treatment in the metastatic setting. After a median follow-up of 17.7 months, the median PFS was 6.9 months (95%CI[5.3-10.7]) and the median OS was 38.3 months (95%CI[26.9-NA]). The ORR was 33.3% (N=19 PR, no CR) whereas N=22 (38.6%) patients had a stable disease at best response. In the subgroup of N=22 (38.6%) patients with somatic PIK3CA mutations, median PFS was 3.1 months (95%CI[2.87-10.9]), while median OS was not reached. In multivariate analysis, somatic PIK3CA mutation was associated with a trend toward a shorter PFS (HR=1.84, 95%CI[0.97-3.99], p=0.06) and OS (HR=2.23, 95%CI[0.88-5.69], p=0.09). Duration of CDK4/6 inhibitor treatment had no overt impact on PFS (HR=0.68, 95%CI[0.38-1.22], p=0.2). Ten (19.6%) patients discontinued everolimus due to toxicity and 17 (29.9%) had at least one dose reduction due to an adverse event. The most grade 3 adverse event were mucositis (10.5%) and hypertriglyceridemia (3.5%), only 1 patient had a grade 3 pneumopathy. At least one mutation trackable by ddPCR was found in N=48 patients. As of July 2022, ctDNA levels have been analyzed in 34 patients (PIK3CAmut: N=19; ESR1mut: N=6; TP53mut: N=4; AKTmut: N=2; CUX1mut: N=1; GATA3mut: N=1; PTENmut: N=1). At baseline, N= 26/34 patients (76.5%) of patients had detectable ctDNA levels. Baseline ctDNA positivity had no prognostic impact on PFS (HR=0.93, 95%CI[0.4-2.13], p=0.86). ctDNA monitoring in the whole cohort will be available for the congress. Conclusion To our knowledge, this is the first prospective study to evaluate the efficacy of fulvestrant-everolimus after progression on CDK4/6 inhibitor. Efficacy data on 57 patients shows that fulvestrant-everolimus is an active regimen in this population. The PFS observed under fulvestrant-everolimus in patients with PIK3CA-mutant mBC appears shorter than previouly reported with alpelisib in the BYLIEVE study. Results of ctDNA to monitor the individual response to therapy will be presented at the congress.

Citation Format: Antoine Vasseur, Caroline Hego, Wissam Taka, Olfa Trabelsi-Grati, Florence Lerebours, Jean-Yves Pierga, Delphine Loirat, Etienne Brain, Paul COTTU, Marie-Paule Sablin, Luc Cabel, Benjamin Renouf, Shufang Renault, Francois-Clement Bidard. ctDNA as dynamic marker of response to fulvestrant and everolimus in CDK4/6 inhibitor-pretreated ER+ HER2- metastatic breast cancer patients: a prospective study [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 P5-02-19.

Genomics to select treatment for patients with metastatic breast cancer

Cancer progression is driven in part by genomic alterations¹. The genomic characterization of cancers has shown interpatient heterogeneity regarding driver alterations², leading to the concept that generation of genomic profiling in patients with cancer could allow the selection of effective therapies^3,4. Although DNA sequencing has been implemented in practice, it remains unclear how to use its results. A total of 1,462 patients with HER2-non-overexpressing metastatic breast cancer were enroled to receive genomic profiling in the SAFIR02-BREAST trial. Two hundred and thirty-eight of these patients were randomized in two trials (nos. NCT02299999 and NCT03386162) comparing the efficacy of maintenance treatment⁵ with a targeted therapy matched to genomic alteration. Targeted therapies matched to genomics improves progression-free survival when genomic alterations are classified as level I/II according to the ESMO Scale for Clinical Actionability of Molecular Targets (ESCAT)⁶ (adjusted hazards ratio (HR): 0.41, 90% confidence interval (CI): 0.27-0.61, P < 0.001), but not when alterations are unselected using ESCAT (adjusted HR: 0.77, 95% CI: 0.56-1.06, P = 0.109). No improvement in progression-free survival was observed in the targeted therapies arm (unadjusted HR: 1.15, 95% CI: 0.76-1.75) for patients presenting with ESCAT alteration beyond level I/II. Patients with germline BRCA1/2 mutations (n = 49) derived high benefit from olaparib (gBRCA1: HR = 0.36, 90% CI: 0.14-0.89; gBRCA2: HR = 0.37, 90% CI: 0.17-0.78). This trial provides evidence that the treatment decision led by genomics should be driven by a framework of target actionability in patients with metastatic breast cancer.

Abstract P2-13-27: Infusion-related reactions in patients receiving pertuzumab and trastuzumab: A retrospective study

BACKGROUND: The use of two anti-HER2 monoclonal antibodies (mAbs) (pertuzumab and trastuzumab) combined with taxanes is the standard of care for first line treatment in HER2-positive metastatic breast cancer (mBC). Infusion related reactions (IRR) during first administration of anti-HER2 mAb have been reported. Reintroduction of the causal drugs is often possible, but there is no data to identify patients at highest risk of developing IRR and modalities of safe reintroduction. The aim of this study was to report patients who experienced IRR during anti-HER2 mAbs infusions at Institut Curie Hospitals (ICH) and to describe these reactions. METHODS: All IRR cases must be reported to the ICH pharmacies. We retrospectively inspected the electronic record of patients who experienced an IRR during pertuzumab (Pmab) and trastuzumab (Tmab). We collected patients’ characteristics, grade of IRR and outcomes. RESULTS: From January 2013 to December 2020, a total of 223 patients had at least one Pmab+Tmab infusion as part of their BC treatment. Among them, 28 patients (8%) with anti-HER2 mAb IRR were identified. All patients but one had an HER2-positive BC; the HER2-negative case was a HER3-mutant mBC. Twelve patients (43%) had de novo mBC. Twenty-six patients (93%) received Pmab+Tmab as first line treatment for mBC. Ten patients were previously exposed to Tmab and three to Pmab+Tmab for (neo)adjuvant treatment. At IRR onset, 21 patients (75%) had liver metastasis, with more than five liver metastases for 19 of them. Fifteen patients (55%) had liver enzymes upper normal limit. IRR occurred during first anti-HER2-mAb infusion in 22 patients (79%) despite pre-treatment with antihistaminic and/or glucosteroids for taxanes. The other IRR were reported at the 2nd, 5th, 6th, 8th and &gt; 10th cycle of Pmab+Tmab. Sixteen IRR (57%) were attributed to Pmab infusion, 9 (32%) to Tmab infusion and 3 (11%) to Tmab and/or Pmab. Al IRR were declared to the pharmacovigilance agency. Majority of reactions were mild to moderate (54% of grade 2). Most frequent symptoms associated with IRR were: thrills (68%), hyperthermia (64%); low oxygen saturation (36%), pain (25%), hypotension (21%), cutaneous (18%) and digestive (18%) reaction. Three patients were transferred to ICU. One death was attributed to anti-HER2 mAb IRR (death was attributed to respiratory distress during the first Tmab infusion). Reintroduction off Pmab+Tmab was performed in 18 patients, after pre-treatment with antihistaminic and/or glucosteroids and with vital function monitoring in conventional hospitalization. No recurrence of IRR was observed in 15/18 patients. For the 3 patients with recurrent IRR, symptoms were mild to moderate. Objective response to anti-HER2 treatments was observed in twenty three patients (82%; 8 complete responses; 15 partial responses). Median PFS was 16 months. CONCLUSIONS: Most anti-Her2-mAb IRR occurs during first infusion, are mild to moderate and do not require a transfer in ICU. Our study suggests that patients with high liver burden might be over-represented among those experiencing an IRR. Reintroduction of Pmab+Tmab was safe in most patients, allowing the continuation of the anti-HER2 dual blockade.

Citation Format: Delphine Loirat, Juliette Logeart, Pauline Vaflard, Aurélien Noret, Mathilde Saint-Ghislain, Edith Borcoman, Audrey Hurgon, Cyrille Cros, Thomas Genevee, Audrey Bellesoeur, Francesco Ricci, Florence Lerebours, Laurence Escalup, Marie-Paule Sablin, François-Clément Bidard, Paul H. Cottu, Jean-Yves Pierga. Infusion-related reactions in patients receiving pertuzumab and trastuzumab: A retrospective study [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 P2-13-27.

Abstract GS1-10: Clinical utility of molecular tumor profiling: Results from the randomized trial SAFIR02-BREAST

Background: While studies have shown feasibility and reported preliminary evidence of utility, there is no evidence that multigene sequencing improves outcome in patients with metastatic cancer. The aim of the present study was to assess the clinical utility of multigene sequencing and DNA copy number analyses.. Methods: In SAFIR02-BREAST (NCT: 02299999) and SAFIR-PI3K (NCT: 03386162), open-label multicentric phase II randomized trials, patients were selected if they had a Her2-negative metastatic breast cancer eligible to 1st or 2nd line chemotherapy. Patients underwent a pre-treatment biopsy of metastatic disease when feasible, followed by genomic analysis by next generation sequencing and SNParray. After 6 to 8 cycles of induction chemotherapy, patients without progressive disease and presenting an actionable genomic alteration, were randomized between targeted therapies matched to genomic alterations or maintenance chemotherapy. The primary objective was to evaluate whether targeted therapies guided by genomics improves progression-free survival (PFS) as compared to maintenance chemotherapy, in a pooled analyses of SAFIR02-BREAST and SAFIR-PI3K populations. A hierarchical testing was applied. The efficacy of targeted therapies matched to genomic alterations was first tested in patients presenting an ESCAT I/II alteration (ESMO Scale of Actionability of Molecular Targets). If a p value &lt;0.1 was observed in the first step, analyses were then performed in the Intent-to-treat population. Results: Out of the 1462 patients included, 238 (16%) were subsequently randomized between maintenance chemotherapy (n=81) and targeted therapy (n=157). In 115 patients presenting an ESCAT I/II genomic alteration, the median PFS was 9.1 months (90%CI: 7.1-9.8) and 2.8 (90%CI: 2.1-4.8) in matched targeted therapy and maintenance chemotherapy arms respectively (adjusted HR for stratification factors =0.41;90%CI: 0.27-0.61, p&lt;0.001). In the overall population, there was no significant difference in the duration of PFS between the two arms (adjusted HR: 0.77 (95%CI: 0.56- 1.06, p=0.109). ESCAT classification was highly predictive for the benefit of targeted therapies matched to genomic alterations (interaction test, p= 0.004). Targeted therapies matched to genomic alterations were not effective in patients without ESCAT I/II alteration (HR: 1.15, 95%CI: 0.76-1.75). The SNP array analyses (n=926) identified 21 genes altered more frequently in metastases as compared to primary tumors (TCGA+ METABRIC). Of these, focal TERT amplifications were associated with a poor outcome. Focal CDK4 amplifications were observed after resistance to CDK4 inhibitors. Finally, high HRD was associated with longer PFS in patients with BRCA mutation treated with olaparib (HR: 0.32 [95%CI: 0.12;0.83], p=0.013).. Conclusion: SAFIR02/PI3K trials report that the clinical use of multigene sequencing must be driven by a framework of actionability, and identifies new genomic alterations associated with metastatic evolution and drug resistance or sensitivity.

Citation Format: Fabrice André, Anthony Gonçalves, Thomas Filleron, Florence Dalenc, Amélie Lusque, Mario Campone, Marie-Paule Sablin, Hervé Bonnefoi, Ivan Bieche, Ludovic Lacroix, Alicia Tran-Dien, Marta Jimenez, Alexandra Jacquet, Qing Wang, Etienne Rouleau, David Gentien, Isabelle Soubeyran, Alain Morel, Monica Arnedos, Thomas Bachelot. Clinical utility of molecular tumor profiling: Results from the randomized trial SAFIR02-BREAST [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 GS1-10.

Genomic Alterations in Head and Neck Squamous Cell Carcinoma: Level of Evidence According to ESMO Scale for Clinical Actionability of Molecular Targets (ESCAT)

Development of high-throughput technologies helped to decipher tumor genomic landscapes revealing actionable molecular alterations. We aimed to rank the level of evidence of recurrent actionable molecular alterations in head and neck squamous cell carcinoma (HNSCC) on the basis of the European Society for Medical Oncology (ESMO) Scale for Clinical Actionability of Molecular Targets (ESCAT) to help the clinicians prioritize treatment. We identified actionable alterations in 33 genes. HRAS-activating mutations were ranked in tier IB because of the efficacy of tipifarnib (farnesyltransferase inhibitor) in HRAS-mutated patients with HNSCC (nonrandomized clinical trial). Microsatellite instability (MSI), high tumor mutational burden (TMB), and NTRK fusions were ranked in tier IC because of PD-1 and TRK tyrosine kinase inhibitors tissue-agnostic approvals. CDKN2A-inactivating alterations and EGFR amplification were ranked in tier IIA because of the efficacy of palbociclib (CDK4/6 inhibitor) and afatinib (tyrosine kinase inhibitor) in these respective molecular subgroups in retrospective analyses of clinical trials. Molecular alterations in several genes, including PIK3CA gene, were ranked in tier IIIA because of clinical benefit in other tumor types, whereas molecular alterations in IGF1R and TP53 genes were ranked in tier IVA and tier V, respectively. The most compelling actionable molecular alterations in HNSCC according to ESCAT include HRAS-activating mutations, MSI, high TMB, NTRK fusions, CDKN2A-inactivating alterations, and EGFR amplification.

Dissociated Responses in Patients with Metastatic Solid Tumors Treated with Immunotherapy

BACKGROUND

Immune checkpoint inhibitors have been demonstrated to improve overall survival. Atypical patterns of response have been reported, including dissociated response (DR). We evaluated the prevalence of DR.

PATIENTS AND METHODS

Patients had to have a baseline computed tomography (CT) scan and at least one follow-up CT scan and two target lesions (TLs). Three types of DR were evaluated using RECIST1.1: DR1, defined as at least one progressive and one responding TL; DR2, defined as at least one progressive and one stable TL; and DR3, defined as at least one stable and one responding TL.

RESULTS

A total of 1244 measurements of 272 TLs were performed in 100 patients. Forty-nine out of the 272 TLs (18%) had received old or recent radiotherapy, and 42 (15%) had been biopsied. An objective response was observed in 22 patients (22%) and on 52 TLs (19%). DR1 were observed in 8% of patients. At the tumor measurement level, the response rate was lower in the case of prior radiotherapy (29% vs 34%, p = 0.01) and higher in the case of prior biopsy (40% vs 32%, p = 0.02).

CONCLUSIONS

A DR was observed in 8% of patients. Response rate was lower in the case of prior radiotherapy and higher in the case of prior biopsy.

Safety, pharmacokinetic, pharmacodynamic and clinical activity of molibresib for the treatment of nuclear protein of the testis carcinoma and other cancers: Results of a Phase I/II open-label, dose escalation study

Molibresib is an orally bioavailable, selective, small molecule BET protein inhibitor. Results from a first time in human study in solid tumors resulted in the selection of a 75 mg once daily dose of the besylate formulation of molibresib as the recommended Phase 2 dose (RP2D). Here we present the results of Part 2 of our study, investigating safety, pharmacokinetics, pharmacodynamics and clinical activity of molibresib at the RP2D for nuclear protein in testis carcinoma (NC), small cell lung cancer, castration-resistant prostate cancer (CRPC), triple-negative breast cancer, estrogen receptor-positive breast cancer and gastrointestinal stromal tumor. The primary safety endpoints were incidence of adverse events (AEs) and serious AEs; the primary efficacy endpoint was overall response rate. Secondary endpoints included plasma concentrations and gene set enrichment analysis (GSEA). Molibresib 75 mg once daily demonstrated no unexpected toxicities. The most common treatment-related AEs (any grade) were thrombocytopenia (64%), nausea (43%) and decreased appetite (37%); 83% of patients required dose interruptions and 29% required dose reductions due to AEs. Antitumor activity was observed in NC and CRPC (one confirmed partial response each, with observed reductions in tumor size), although predefined clinically meaningful response rates were not met for any tumor type. Total active moiety median plasma concentrations after single and repeated administration were similar across tumor cohorts. GSEA revealed that gene expression changes with molibresib varied by patient, response status and tumor type. Investigations into combinatorial approaches that use BET inhibition to eliminate resistance to other targeted therapies are warranted.

Abstract PD14-03: Molecular mechanism of ipatasertib (IPAT) and its combination with atezolizumab (atezo) in patients (pts) with locally advanced/metastatic triple-negative breast cancer (aTNBC)

Background: Phase 3 trials (IMpassion130, KEYNOTE-355) have shown improved efficacy with the addition of immune checkpoint modulators to chemotherapy in PD-L1 +ve aTNBC. However, unmet need remains in the ~60% of pts with aTNBC who have PD-L1 -ve tumors. Preliminary data from a multicenter phase 1b study (NCT03800836) evaluating the safety and efficacy of the oral AKT inhibitor IPAT + atezo + paclitaxel/nab-paclitaxel showed promising antitumor activity (73% confirmed objective response rate) irrespective of PD-L1 status [Schmid, AACR 2019], suggesting a potential role for the triplet independent of PD-L1 status. We report on-treatment changes in the tumor microenvironment in Cohort 2.

Methods: In Cohort 2, pts with aTNBC and ≤2 prior lines of chemotherapy for aTNBC received oral IPAT 400 mg on d1-28 of cycle 1 (35-d cycle) and on d1-21 of subsequent cycles (28-d cycles). IV atezo 840 mg was given on d8 & 22 of cycle 1 and on d1 & 15 of subsequent cycles. Biopsies were collected before treatment administration during cycle 1 on d1 (C1D1) & d8 (C1D8), and on d15 of cycle 2 (C2D15). PD-L1 (VENTANA SP142 immune cell ≥1%) and CD8 expression was assessed by immunohistochemistry (IHC); % immune infiltrate was measured by H&E staining. Changes in gene expression were assessed by RNA-Seq. Gene set enrichment analysis was used to study molecular pathway activation (enrichment score [ES] &gt;0 to 1) or inhibition (ES -1 to &lt;0).

Results: In Cohort 2, 11 pts had PD-L1 -ve tumors at baseline and are included in the analyses below, 2 had PD-L1 +ve tumors and 3 were unevaluable for PD-L1. IHC analysis of serial biopsies from pts with PD-L1 -ve tumors showed a statistically significant increase in immune infiltrates (mean % infiltrates C1D8/C1D1=1.44; p=0.042) and a trend toward increased CD8 protein expression (mean CD8 % staining C1D8/C1D1=1.75; Kruskal-Wallis p=0.16) at the tumor center during the first week of single-agent IPAT compared with the baseline biopsy. An increase in PD-L1 expression (mean PD-L1 % infiltrating immune cells C2D15/C1D1=4.33; Kruskal-Wallis p=0.044) was seen during IPAT + atezo combination treatment. No significant changes in immune infiltrates or CD8 expression were observed after initiating atezo versus IPAT alone. As expected, MTORC1 activity decreased (ES=-0.43; p&lt;0.005) in response to IPAT. IPAT (± atezo) enhanced key immunogenic pathways, including antigen processing and presentation (ES=0.49; p&lt;0.005), allograft rejection (ES=0.47; p&lt;0.0001), inflammatory response (ES=0.34; p&lt;0.05), and NK cell activation (ES=0.66; p&lt;0.05). In addition, IPAT + atezo enhanced TCR signaling (ES=0.52; p&lt;0.0005) and interferon gamma response (ES=0.30; p&lt;0.05). IPAT treatment was associated with decreased expression of gene sets predicting pathway upregulation, including E2F signaling, G2M checkpoint, and MYC activity. IPAT was also associated with apoptotic pathway enrichment. Using a syngeneic melanoma mouse model, we validated clinical findings and identified additional molecular changes after treatment with IPAT and/or anti-PD-L1. To date, 3 enrolled pts achieved a partial response and 6 had stable disease. Clinical and preclinical studies are ongoing to explore associations between treatment-driven molecular changes and clinical response.

Conclusion: Inhibition of AKT signaling may remodel the microenvironment of PD-L1 -ve tumors by increasing immune infiltration, priming immune pathways, promoting tumor cell apoptosis, and inhibiting oncogenic cell proliferative pathways. To our knowledge, these are the first reports evaluating molecular changes during AKT-targeted therapy for aTNBC in the context of immunotherapy irrespective of PD-L1 status. IPAT warrants further investigation combined with atezo as treatment for PD-L1 -ve aTNBC.

Citation Format: Peter Schmid, Delphine Loirat, Peter Savas, Enrique Espinosa, Valentina Boni, Antoine Italiano, Shane White, Victor Laliman, Geraldine Strasser, Kui Lin, Karen Cheng, Aruna Mani, Matthew Wongchenko, Marie-Paule Sablin, Kalpit Shah. Molecular mechanism of ipatasertib (IPAT) and its combination with atezolizumab (atezo) in patients (pts) with locally advanced/metastatic triple-negative breast cancer (aTNBC) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD14-03.

Abstract PS12-28: Phase 1b study evaluating a triplet combination of ipatasertib (IPAT), atezolizumab, and a taxane as first-line therapy for locally advanced/metastatic triple-negative breast cancer (TNBC)

Background: The combination of immune checkpoint modulators with chemotherapy improves efficacy compared with chemotherapy alone in PD-L1+ advanced TNBC (IMpassion130; KEYNOTE-355). The addition of IPAT to paclitaxel (PAC) improved efficacy in a phase 2 trial in advanced TNBC (LOTUS). Preliminary overall response rate (ORR) data from a multicenter phase 1b study (NCT03800836) evaluating a triplet combination of IPAT, atezolizumab, and taxane chemotherapy showed promising anti-tumor activity in a similar patient population, irrespective of PD-L1 status [Schmid, AACR 2019]. Here, we report follow-up results including progression-free survival (PFS) from this study. Patients and Methods: Eligible patients had measurable unresectable locally advanced/metastatic TNBC, ECOG performance status 0/1, and had received no prior systemic therapy for advanced disease (prior [neo]adjuvant chemotherapy and/or radiation permitted if all chemotherapy was completed ≥12 months before first dose). Patients with brain metastases were excluded. Patients received oral IPAT 400 mg/day on days 1–21 and IV atezolizumab 840 mg on days 1 & 15 in combination with PAC 80 mg/m2 (Arm A) or nab-PAC 100 mg/m2 (Arm B) on days 1, 8, & 15. Cycles were repeated every 28 days until loss of clinical benefit, unacceptable toxicity, or consent withdrawal. Arms C and D evaluated sequential regimens comprising a doublet induction therapy with the third agent added on day 15 (Arm C: IPAT + PAC, then + atezolizumab; Arm D: atezolizumab + PAC, then + IPAT). Tumors were assessed every 8 weeks. Key endpoints were confirmed ORR (per RECIST v1.1), duration of response (DoR), PFS, and safety. Results: At the data cut-off (26 Jul 2020), results were available from 114 patients (Arm A n=70, Arm B n=20, Arm C n=12, Arm D n=12). Median duration of follow-up was 11.1 months. Efficacy results are summarized in the table. Safety of the combination appeared to be consistent with the known safety profile of the individual drugs. Grade ≥3 adverse events (AEs) occurred in 55% of patients (including rash [13%], diarrhea [12%], and neutropenia [10%]) and serious AEs in 34%. AEs led to discontinuation of IPAT in 6% of patients and atezolizumab in 4%. No new safety signals were identified.

Conclusions: Updated results demonstrate a lower ORR than in the preliminary report of the first 26 patients. Subgroup analyses according to PD-L1 or PIK3CA/AKT1/PTEN alteration status or taxane backbone show no consistent trend across endpoints, although small sample sizes limit interpretation. Further biomarker analyses focusing on subgroups and biology may identify subsets of patients deriving a benefit.

PopulationConfirmed ORR, n (%) [95% CI]Median DoR, months (95% CI)aMedian PFS, months (95% CI)All patients (n=114)61 (54) [44–63]7.3 (5.6–7.8)7.2 (5.5–7.4)PD-L1 statusbPositive (n=51)32 (63) [48–76]7.4 (5.0–12.9)7.3 (5.4–7.4)Negative (n=45)20 (44) [30–60]5.6 (3.7–7.4)7.2 (5.4–9.1)Unknown (n=18)9 (50) [26–74]11.1 (5.8–NE)6.3 (4.9–11.0)Arm (taxane backbone)A (PAC) (n=70)36 (51) [39–64]7.4 (5.6–12.9)7.2 (5.3–7.4)B (nab-PAC) (n=20)13 (65) [41–85]7.3 (3.9–7.4)6.6 (3.4–9.0)C+D (PAC) (n=12+12)12 (50) [29–71]6.8 (3.9–14.7)7.5 (5.5–11.3)PIK3CA/AKT1/PTEN statuscAltered (n=36)d19 (53) [35–70]6.8 (3.9–7.6)7.4 (5.5–9.1)Non-altered (n=45)28 (62) [47–76]7.3 (5.5–9.4)6.6 (5.2–9.0)Unknown (n=33)14 (42) [25–61]10.2 (5.8–NE)6.0 (5.1–9.1)aIn responding patients. bAssessed by VENTANA SP142 immunohistochemistry assay (Ventana Medical Systems, Tucson, AZ, USA); PD-L1+ defined as immune cell expression in ≥1% of the tumor area. cAssessed using FoundationOne CDx (Foundation Medicine, Cambridge, MA, USA). dPIK3CA/AKT mutation (n=12) or PTEN alteration (n=24). CI = confidence interval; nab = nanoparticle albumin-bound; NE = not estimable.

Citation Format: Peter Schmid, Peter Savas, Enrique Espinosa, Valentina Boni, Antoine Italiano, Shane White, Karen Cheng, Lisa Lam, Lidia Robert, Victor Laliman, Kalpit Shah, Marie-Paule Sablin. Phase 1b study evaluating a triplet combination of ipatasertib (IPAT), atezolizumab, and a taxane as first-line therapy for locally advanced/metastatic triple-negative breast cancer (TNBC) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS12-28.

A phase Ib/II study of xentuzumab, an IGF-neutralising antibody, combined with exemestane and everolimus in hormone receptor-positive, HER2-negative locally advanced/metastatic breast cancer

Background

Xentuzumab—a humanised IgG1 monoclonal antibody—binds IGF-1 and IGF-2, inhibiting their growth-promoting signalling and suppressing AKT activation by everolimus. This phase Ib/II exploratory trial evaluated xentuzumab plus everolimus and exemestane in hormone receptor-positive, locally advanced and/or metastatic breast cancer (LA/MBC).

Methods

Patients with hormone receptor-positive/HER2-negative LA/MBC resistant to non-steroidal aromatase inhibitors were enrolled. Maximum tolerated dose (MTD) and recommended phase II dose (RP2D) of xentuzumab/everolimus/exemestane were determined in phase I (single-arm, dose-escalation). In phase II (open-label), patients were randomised 1:1 to the RP2D of xentuzumab/everolimus/exemestane or everolimus/exemestane alone. Randomisation was stratified by the presence of visceral metastases. Primary endpoint was progression-free survival (PFS).

Results

MTD was determined as xentuzumab 1000 mg weekly plus everolimus 10 mg/day and exemestane 25 mg/day. A total of 140 patients were enrolled in phase II (70 to each arm). Further recruitment was stopped following an unfavourable benefit-risk assessment by the internal Data Monitoring Committee appointed by the sponsor. Xentuzumab was discontinued; patients could receive everolimus/exemestane if clinically indicated. Median PFS was 7.3 months (95% CI 3.3–not calculable) in the xentuzumab/everolimus/exemestane group and 5.6 months (3.7–9.1) in the everolimus/exemestane group (hazard ratio 0.97, 95% CI 0.57–1.65; P = 0.9057). In a pre-specified subgroup of patients without visceral metastases at screening, xentuzumab/everolimus/exemestane showed evidence of PFS benefit versus everolimus/exemestane (hazard ratio 0.21 [0.05–0.98]; P = 0.0293). Most common any-cause adverse events in phase II were diarrhoea (29 [41.4%] in the xentuzumab/everolimus/exemestane group versus 20 [29.0%] in the everolimus/exemestane group), mucosal inflammation (27 [38.6%] versus 21 [30.4%]), stomatitis (24 [34.3%] versus 24 [34.8%]), and asthenia (21 [30.0%] versus 24 [34.8%]).

Conclusions

Addition of xentuzumab to everolimus/exemestane did not improve PFS in the overall population, leading to early discontinuation of the trial. Evidence of PFS benefit was observed in patients without visceral metastases when treated with xentuzumab/everolimus/exemestane, leading to initiation of the phase II XENERA™-1 trial (NCT03659136).

Trial registration

ClinicalTrials.gov, NCT02123823. Prospectively registered, 8 March 2013.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13058-020-01382-8.

Real-world Evaluation of Oral Vinorelbine in the Treatment of Metastatic Breast Cancer: An ESME-MBC Study

BACKGROUND/AIM

Vinorelbine is indicated for use in the treatment of MBC as a single agent or in combination but there is little real world data on this molecule and even less on its oral form. We exploited the Unicancer Epidemiology Strategy Medical-Economics (ESME) metastatic breast cancer (MBC) database to investigate current patterns of use of oral vinorelbine (OV), as well as outcomes of patients receiving this drug.

PATIENTS AND METHODS

Data were collected retrospectively from women and men treated for MBC between 2008 and 2014 at one of 18 French Comprehensive Cancer Centres. The efficacy of OV was evaluated in terms of progression-free (PFS) and overall survival (OS) and treatment duration. The population and patterns of OV usage were also described.

RESULTS

A total of 1806 patients (11% of the ESME MBC database) were included in this analysis. OV was prescribed as monotherapy (46%) or in combination (29%), especially with capecitabine. mainly in later treatment lines. Median PFS was 3.3 months: 2.9 months for single agent, 3.6 months for combination therapy. Median OS was 40.9 months.

CONCLUSION

Real-world data offer complementary results to the data from traditional clinical trials, but they concern a much larger population. In this ESME MBC cohort, OV was only prescribed to a small subset of MBC patients. OV was mainly given as single agent to patients with heavily pre-treated MBC; less commonly, it was co-administered with capecitabine or anti-HER2, in earlier lines of therapy. PFS was modest but in line with previous reports.

Capivasertib, an AKT Kinase Inhibitor, as Monotherapy or in Combination with Fulvestrant in Patients with AKT1 E17K-Mutant, ER-Positive Metastatic Breast Cancer

PURPOSE

The activating mutation AKT1 E17K occurs in approximately 7% of estrogen receptor-positive (ER+) metastatic breast cancer (MBC). We report, from a multipart, first-in-human, phase I study (NCT01226316), tolerability and activity of capivasertib, an oral AKT inhibitor, as monotherapy or combined with fulvestrant in expansion cohorts of patients with AKT1 E17K-mutant ER+ MBC.

PATIENTS AND METHODS

Patients with an AKT1 E17K mutation, detected by local (next-generation sequencing) or central (plasma-based BEAMing) testing, received capivasertib 480 mg twice daily, 4 days on, 3 days off, weekly or 400 mg twice daily combined with fulvestrant at the labeled dose. Study endpoints included safety, objective response rate (ORR; RECIST v1.1), progression-free survival (PFS), and clinical benefit rate at 24 weeks (CBR24). Biomarker analyses were conducted in the combination cohort.

RESULTS

From October 2013 to August 2018, 63 heavily pretreated patients received capivasertib (20 monotherapy, 43 combination). ORR was 20% with monotherapy, and within the combination cohort was 36% in fulvestrant-pretreated and 20% in fulvestrant-naïve patients, although the latter group may have had more aggressive disease at baseline. AKT1 E17K mutations were detectable in plasma by BEAMing (95%, 41/43), droplet digital PCR (80%, 33/41), and next-generation sequencing (76%, 31/41). A ≥50% decrease in AKT1 E17K at cycle 2 day 1 was associated with improved PFS. Combination therapy appeared more tolerable than monotherapy [most frequent grade ≥3 adverse events: rash (9% vs. 20%), hyperglycemia (5% vs. 30%), diarrhea (5% vs. 10%)].

CONCLUSIONS

Capivasertib demonstrated clinically meaningful activity in heavily pretreated patients with AKT1 E17K-mutant ER+ MBC, including those with prior disease progression on fulvestrant. Tolerability and activity appeared improved by the combination.

Genomic Profiling of Metastatic Uveal Melanoma and Clinical Results of a Phase I Study of the Protein Kinase C Inhibitor AEB071

Up to 50% of patients with uveal melanoma (UM) develop metastatic disease, for which there is no effective systemic treatment. This study aimed to evaluate the safety and efficacy of the orally available protein kinase C inhibitor, AEB071, in patients with metastatic UM, and to perform genomic profiling of metastatic tumor samples, with the aim to propose combination therapies. Patients with metastatic UM (n = 153) were treated with AEB071 in a phase I, single-arm study. Patients received total daily doses of AEB071 ranging from 450 to 1,400 mg. First-cycle dose-limiting toxicities were observed in 13 patients (13%). These were most commonly gastrointestinal system toxicities and were dose related, occurring at doses ≥700 mg/day. Preliminary clinical activity was observed, with 3% of patients achieving a partial response and 50% with stable disease (median duration 15 weeks). High-depth, targeted next-generation DNA sequencing was performed on 89 metastatic tumor biopsy samples. Mutations previously identified in UM were observed, including mutations in GNAQ, GNA11, BAP1, SF3B1, PLCB4, and amplification of chromosome arm 8q. GNAQ/GNA11 mutations were observed at a similar frequency (93%) as previously reported, confirming a therapeutic window for inhibition of the downstream effector PKC in metastatic UM.In conclusion, the protein kinase C inhibitor AEB071 was well tolerated, and modest clinical activity was observed in metastatic UM. The genomic findings were consistent with previous reports in primary UM. Together, our data allow envisaging combination therapies of protein kinase C inhibitors with other compounds in metastatic UM.

Comparative Analysis of Durable Responses on Immune Checkpoint Inhibitors Versus Other Systemic Therapies: A Pooled Analysis of Phase III Trials

PURPOSE

Immune checkpoint inhibitors (ICIs) have been demonstrated to improve overall survival (OS) in several tumor types. Durable responses have been reported with these agents in patients with melanoma and lung cancer. We aimed to quantify the proportion of patients who experience durable responses on ICIs and to compare it with other drug classes.

PATIENTS AND METHODS

We retrieved published phase III randomized trials that included at least one ICI arm in the recurrent and/or metastatic setting. A durable response to treatment was defined as a progression-free survival that exceeded three times the median progression-free survival of the whole population. The proportion of patients who experienced an OS that exceeded two times the median OS of the whole patient population also was estimated.

RESULTS

Nineteen studies involving 11,640 patients treated in 42 treatment arms (26 ICI and 16 non-ICI arms) were included. The mean proportion of patients who experienced a durable response was 2.3 times higher in those treated with an ICI compared with those treated in the control arms (25% v 11%). Durable responses were more frequent in patients treated with anti–PD-1/PD-L1 agents than in patients treated with anti–CTLA-4 agents (28% v 18%). The mean proportion of patients who had an OS that exceeded two times the median OS was also higher in those treated with ICIs than in those treated in the control arms (30% v 23%). In multivariable analysis, the effects of treatment with anti–PD-1/PD-L1 agents and of first-line treatment were statistically associated with a higher mean proportion of durable responses.

CONCLUSION

Durable responses were more frequent in patients treated with ICIs, although they also occurred in patients treated with other drug classes.

Actionability of HER2-amplified circulating tumor cells in HER2-negative metastatic breast cancer: the CirCe T-DM1 trial

BACKGROUND

In this prospective phase 2 trial, we assessed the efficacy of trastuzumab-emtansine (T-DM1) in HER2-negative metastatic breast cancer (MBC) patients with HER2-positive CTC.

METHODS

Main inclusion criteria for screening were as follows: women with HER2-negative MBC treated with ≥ 2 prior lines of chemotherapy and measurable disease. CTC with a HER2/CEP17 ratio of ≥ 2.2 by fluorescent in situ hybridization (CellSearch) were considered to be HER2-amplified (HER2_amp). Patients with ≥ 1 HER2_amp CTC were eligible for the treatment phase (T-DM1 monotherapy). The primary endpoint was the overall response rate.

RESULTS

In 154 screened patients, ≥ 1 and ≥ 5 CTC/7.5 ml of blood were detected in N = 118 (78.7%) and N = 86 (57.3%) patients, respectively. ≥1 HER2_amp CTC was found in 14 patients (9.1% of patients with ≥ 1 CTC/7.5 ml). Among 11 patients treated with T-DM1, one achieved a confirmed partial response. Four patients had a stable disease as best response. Median PFS was 4.8 months while median OS was 9.5 months.

CONCLUSIONS

CTC with HER2 amplification can be detected in a limited subset of HER2-negative MBC patients. Treatment with T-DM1 achieved a partial response in only one patient.

TRIAL REGISTRATION

NCT01975142, Registered 03 November 2013.

Pooled analysis of onapristone extended release (ONA ER) in metastatic cancer patients (pts): A review of liver safety

e14647

Background: ONA, a type I progesterone receptor (PR) antagonist, prevents PR activation by disrupting PR dimerization and DNA binding, and inhibits tumor progression. ONA (immediate release) has efficacy comparable to other endocrine therapies in pts with metastatic breast cancer (BC). The only notable toxicity was transient elevation in liver chemistries in some pts. In 2 clinical trials, ONA ER was given to 88 cancer pts who underwent frequent liver chemistry monitoring. Methods: We pooled and reviewed all liver safety data from 2 trials. A hepatologist (PBW) reviewed all pts with either a hepatobiliary SOC AE or who experienced an elevation > ULN of any liver-related laboratory test. Results: Of 88 pts who received ONA ER for a median 8 weeks (3-51), 59% were female, median age 68 (36-89), 99% Caucasian, 28% had liver metastases (mets), 48% bone mets and 17% also took abiraterone (ABI), which has liver toxicity. 54 pts (61%) experienced any ONA ER-related AE. More AEs were seen in ABI pts (67%), those with liver mets (72%) and BC (76%).. In terms of liver-related TEAEs, overall 10% of pts had ALT and 13% AST elevations, while 20% pts with liver mets had raised ALT/AST and 29% of BC pts. Overall 15% pts had G3 TEAEs, compared to 28% pts with liver mets, mostly due to increased GGT (24%), which has unclear clinical impact. There were no discontinuations for LFT elevations. A relationship between the liver events and ONA ER was judged to be unlikely in each subject, except one. This event was detected at day 29 of treatment and consisted of a marked rise in serum GGT and alkaline phosphatase with only a moderate rise in serum ALT (peak – 262). These abnormalities improved quickly after stopping ONA but recurred on reintroduction: these events are not serious by international criteria and the pt was able to continue ONA at a lower dose for 40 weeks without recurrence Conclusions: The safety experience for ONA ER has been reassuring but must continue to be characterized. For new ONA ER studies, weekly liver chemistry monitoring is planned for the first 4 weeks with Q2W monitoring thereafter. The occasional G3 elevations in serum AST, ALT or bilirubin will prompt interruption, but re-starting treatment at a lower dose should be possible for most pts. Clinical trial information: NCT02052128 and NCT02049190.

RUBY: A phase II study testing rucaparib in germline (g) BRCA wild-type patients presenting metastatic breast cancer (mBC) with homologous recombination deficiency (HRD)

1092

Background: PARP-inhibitors improve PFS in mBC patients (pts) harboring a gBRCA mutation (mut). However, unlike ovarian cancer, there is no evidence until now that this class of agents has efficacy in gBRCA wild-type (WT) pts. In RUBY, we evaluated rucaparib in gBRCA WT mBC pts, and whose tumor present with HRD as assessed by genome-wide Loss of Heterozygosity (LOH) score. Methods: 713 gBRCA WT women with HER2- mBC, initiating a first metastatic chemo, were screened for high (≥18%) genomic tumor LOH generated from a SNP array on metastatic sample. Eligible pts with a high LOH score or somatic (s) BRCA mut and ≥1 prior chemo regimen were proposed to enter RUBY and receive oral rucaparib 600 mg BID continuously in 28-day cycles until disease progression. The primary endpoint was clinical benefit rate (CBR), defined by complete (CR) and partial response (PR) or stable disease (SD) ≥16 weeks. We used a Simon’s two-stage design (p0=20%; p1=40%), responses in ≥4/17 pts were expected to move to second step, and ≥11/37 pts to be considered of clinical interest (α=10% and power of 90%). Whole genome sequencing (WGS) was performed retrospectively to further assess potential biomarkers of PARP inhibitor response. Results: Tumors from 221 (31%) pts were LOH high. 41 pts were enrolled, including 4 pts with sBRCA mut. Median prior metastatic chemo lines was 2 (1-5), 17 pts had TNBC at diagnosis. As of 14 Jan 2019, 16 pts were alive, 5 are still on treatment. The median number of cycles was 2 (1 -20), and 37/40 patients were evaluable for CBR. 5 pts (13.5%) demonstrated clinical benefit (1 CR [LOH high], 3 PR [2 LOH high, 1 sBRCA2] and 1 SD>31 weeks [sBRCA1]). 19 pts had grade 3-4 toxicities. 3 pts discontinued due to toxicity. 4/5 responders pts had their tumor profiled by WGS: preliminary analyses showed that 4 pts presented high large scale state transitions, and 3 presented a somatic biallelic loss of function in HR-related genes. The fifth responder harbored a mut on gPALB2 and sBRCA2 at inclusion. Conclusions: In this study, rucaparib demonstrates antitumor activity in a subset of gBRCA WT mBC pts whose tumor has high LOH. Final analyses of WGS will provide insights about HRD signatures and drivers alterations associated with response. Clinical trial information: NCT02505048.

Phase I dose-escalation study of F14512, a polyamine-vectorized topoisomerase II inhibitor, in patients with platinum-refractory or resistant ovarian cancer

Purpose To determine the maximum tolerated dose (MTD) of F14512, a topoisomerase II inhibitor designed to target cancer cells through the polyamine transport system, (three-hour daily infusion given for 3 consecutive days every 3 weeks) in platinum-refractory or resistant ovarian cancer. Other objectives were safety, pharmacokinetics (PK), PK/pharmacodynamics relationship, and efficacy. Methods This was an open-label, dose-escalation, multicenter phase I study. Results Eleven patients were enrolled and were treated at dose levels (DLs) of 10 and 5 mg/m²/day. All patients received the 3 injections per cycle as per study protocol (median, 1 cycle (Ferlay et al. Int J Cancer 136:E359–386, 2015; Siegel et al. CA Cancer J Clin 65:5–29, 2015; Oronsky et al. Med Oncol 34:103, 2017; Barret et al. Cancer Res 68:9845–9853, 2008; Ballot et al. Apoptosis 17:364–376, 2012; Brel et al. Biochem Pharmacol 82:1843–1852, 2011; Gentry et al. Biochemistry 50:3240–3249, 2011; Kruczynski et al. Investig New Drugs 29:9–21, 2011; Chelouah et al. PLoS One 6:e23597, 2011)) with no dose reductions. At DL 10 mg/m²/day, 6 dose-limiting toxicities (DLTs) were reported (3/4 evaluable patients: 2 grade 3 febrile neutropenia, 1 grade 4 neutropenia lasting at least 7 days, 1 grade 3 nausea, 1 decreased appetite, and 1 grade 3 asthenia). At dose 5 mg/m²/day, 2 DLTs were reported (2/6 treated patients: 2 grade 3 febrile neutropenia). Both DLs were defined as MTD. Stable disease was reported as best overall response in 2 (40%) patients having both received 9 cycles, one at each DL. 90.9% of patients experienced grade 4 neutropenia, but for only one (9.1%) it was reported as a serious adverse event. Conclusion Although there was some encouraging efficacy signal, grade 4 neutropenia led to complications and it was decided to stop the study. A DL below 5 mg/m²/day was not tested as this would not allow reaching the minimum serum concentration needed for the pharmacological activity of the drug.

Exploitation of Precision Medicine Trials Data: Examples of Long Responders From the SHIVA01 Trial

Purpose

Precision medicine trials constitute a precious source of molecular data with prospective clinical annotations allowing the exploration of patients’ subpopulations according to specific clinical or biological questions. Using the SHIVA01—the first randomized trial comparing molecularly targeted therapy on the basis of tumor molecular profiling versus conventional chemotherapy in metastatic cancer patients who failed standard of care therapy—annotated database, we report cases of patients treated in the trial with targeted therapy who experienced an objective response or prolonged disease stabilization in light of patients’ molecular alterations.

Patients and Methods

We selected all patients included in SHIVA01 treated with a molecularly targeted agent (MTA) who experienced an objective response or disease stabilization that lasted longer than 6 months according to Response Evaluation Criteria in Solid Tumors version 1.1.

Results

Among the 170 patients who received MTAs in the SHIVA01 trial, 15 patients (9%) experienced an objective response (n = 3) or disease stabilization that lasted longer than 6 months (n = 12). The most frequent histologic subtypes were breast cancer (27%) and cervical cancer (20%). Six patients, including three patients with breast cancer, were treated with abiraterone on the basis of androgen receptor protein overexpression. Five patients were treated with everolimus on the basis of a PTEN heterozygous deletion with loss of protein expression, PIK3CA mutation, or both alterations. The remaining four patients were treated with tamoxifen, erlotinib, imatinib, and vemurafenib on the basis of progesterone receptor expression, EGFR amplification, KIT mutation, and BRAF mutation, respectively. TP53 mutations were absent in responder patients.

Conclusion

Analysis of patients who experienced objective responses or disease stabilization that lasted longer than 6 months allowed the identification of potential biomarkers of sensitivity and resistance to MTAs.

Phase I study of onapristone, a type I antiprogestin, in female patients with previously treated recurrent or metastatic progesterone receptor-expressing cancers

INTRODUCTION

Onapristone is a type I progesterone receptor (PR) antagonist, which prevents PR- mediated DNA transcription. Onapristone is active in multiple preclinical models and two prior studies demonstrated promising activity in patients with breast cancer. We conducted a study of extended release (ER) Onapristone to determine a recommended dose and explore the role of transcriptionally-activated PR (APR), detected as an aggregated subnuclear distribution pattern, as a predictive biomarker.

METHODS

An open-label, multicenter, randomized, parallel-group, phase 1 study (target n = 60; NCT02052128) included female patients ≥18 years with PRpos tumors. APR analysis was performed on archival tumor tissue. Patients were randomized to five cohorts of extended release (ER) onapristone tablets 10, 20, 30, 40 or 50 mg BID, or immediate release 100 mg QD until progressive disease or intolerability. Primary endpoint was to identify the recommended phase 2 dose. Secondary endpoints included safety, clinical benefit and pharmacokinetics.

RESULTS

The phase 1 dose escalation component of the study is complete (n = 52). Tumor diagnosis included: endometrial carcinoma 12; breast cancer 20; ovarian cancer 13; other 7. Median age was 64 (36-84). No dose limiting toxicity was observed with reported liver function test elevation related only to liver metastases. The RP2D was 50 mg ER BID. Median therapy duration was 8 weeks (range 2-44), and 9 patients had clinical benefit ≥24 weeks, including 2 patients with APRpos endometrial carcinoma.

CONCLUSION

Clinical benefit with excellent tolerance was seen in heavily pretreated patients with endometrial, ovarian and breast cancer. The data support the development of Onapristone in endometrial endometrioid cancer. Onapristone should also be evaluated in ovarian and breast cancers along with APR immunohistochemistry validation.

Abstract OT3-06-02: A phase Ib trial of xentuzumab and abemaciclib in patients with locally advanced or metastatic solid tumors, including hormone receptor-positive, HER2-negative breast cancer (plus endocrine therapy)

Background: Resistance to endocrine therapy remains an important clinical problem in hormone receptor-positive (HR+), HER2-negative (HER2-) breast cancer (BC), necessitating alternative treatment options. The insulin-like growth factor (IGF) axis and cyclin D-cyclin-dependent kinase (CDK) 4/6-retinoblastoma pathway have been implicated in the pathogenesis and resistance mechanisms of a variety of cancers, including BC. Binding of IGF-I and -II to the IGF receptor results in upregulation of cyclin D1, and subsequent progression through the cell cycle, thus providing rationale for the simultaneous inhibition of IGF-I and -II and CDK4/6. This Phase Ib trial assesses the maximum-tolerated dose (MTD)/recommended phase II dose (RP2D), safety and preliminary efficacy of the IGF-ligand-neutralizing antibody, xentuzumab, in combination with abemaciclib, a selective, small-molecule inhibitor of both CDK4 and 6, in patients (pts) with solid tumors. The trial includes four dose finding cohorts followed by two expansion cohorts. Only those cohorts that will include pts with postmenopausal HR+, HER2- BC will be presented here.

Trial design: In this phase Ib multicenter, non-randomized, open-label, dose escalation trial (BI 1280.18 [NCT03099174]), the key aims in the BC cohorts (Cohorts B–D, F) are to define the MTD or recommended phase 2 dose (RP2D), and to evaluate the preliminary efficacy, safety and tolerability of xentuzumab plus abemaciclib in combination with endocrine therapies. Eligible pts include adults ≥18 yrs (≥20 for Japan), with measurable or evaluable disease, adequate organ function, ECOG PS ≤1, and postmenopausal locally advanced or metastatic HR+, HER2- BC (Cohorts B–D, F). CDK4/6 inhibitor-naïve pts (Cohorts B–D) and pts who have received prior CDK4/6 inhibitors (palbociclib or ribociclib) plus aromatase inhibitors (Cohort F) are included. The MTD/RP2D of xentuzumab plus abemaciclib to be used in Cohorts B–D will be established in pts with solid tumors (Cohort A) who will receive xentuzumab (starting dose 1000mg weekly iv) plus abemaciclib (starting dose 150mg every 12 hours). CDK4/6 inhibitor-naïve pts with BC will receive xentuzumab plus abemaciclib at the RP2D determined in Cohort A in combination with letrozole (2.5mg/day; Cohort B), anastrozole (1mg/day; Cohort C), or fulvestrant (500mg/month; Cohort D). CDK4/6 inhibitor pre-treated pts with BC (Cohort F) will receive xentuzumab plus abemaciclib and fulvestrant at the RP2D determined in Cohort D. Primary endpoints in the BC cohorts are the MTD and/or RP2D of xentuzumab plus abemaciclib in combination with endocrine therapies, and the objective response (OR) in CDK4/6 inhibitor pre-treated pts with advanced BC (Cohort F); disease control (DC), duration of DC, time to OR, duration of OR, and progression-free survival (PFS) in Cohort F are secondary endpoints. Additionally, PK outcomes, safety and tolerability will be assessed in all cohorts. This study will be conducted in the US, Europe and Japan. Pt screening started in May 2017. Target enrolment is ˜88 pts, including ˜56 pts with advanced HR+, HER2- BC, of whom ˜20 had previously been treated with CDK 4/6 inhibitors.

Citation Format: Yee D, Sablin MP, Iwata H, Johnston EL, Bogenrieder T, Serra J, Hua H, Lo Russo P, Prat A. A phase Ib trial of xentuzumab and abemaciclib in patients with locally advanced or metastatic solid tumors, including hormone receptor-positive, HER2-negative breast cancer (plus endocrine therapy) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT3-06-02.

Comprehensive genomic profiling of head and neck squamous cell carcinoma reveals FGFR1 amplifications and tumour genomic alterations burden as prognostic biomarkers of survival

BACKGROUND

We aimed at identifying deleterious genomic alterations from untreated head and neck squamous cell carcinoma (HNSCC) patients, and assessing their prognostic value.

PATIENTS AND METHODS

We retrieved 122 HNSCC patients who underwent primary surgery. Targeted NGS was used to analyse a panel of 100 genes selected among the most frequently altered genes in HNSCC and potential therapeutic targets. We selected only deleterious (activating or inactivating) single nucleotide variations, and copy number variations for analysis. Univariate and multivariate analyses were performed to assess the prognostic value of altered genes.

RESULTS

A median of 2 (range: 0-10) genomic alterations per sample was observed. Most frequently altered genes involved the cell cycle pathway (TP53 [60%], CCND1 [30%], CDKN2A [25%]), the PI3K/AKT/MTOR pathway (PIK3CA [12%]), tyrosine kinase receptors (EGFR [9%], FGFR1 [5%]) and cell differentiation (FAT1 [7%], NOTCH1 [4%]). TP53 mutations (p = 0.003), CCND1 amplifications (p = 0.04), CDKN2A alterations (p = 0.02) and FGFR1 amplifications (p = 0.003), correlated with shorter overall survival (OS). The number of genomic alterations was significantly higher in the HPV-negative population (p = 0.029) and correlated with a shorter OS (p < 0.0001). Only TP53 mutation and FGFR1 amplification status remained statistically significant in the multivariate analysis.

CONCLUSION

These results suggest that genomic alterations involving the cell cycle (TP53, CCND1, CDKN2A), as well as FGFR1 amplifications and tumour genomic alterations burden are prognostic biomarkers and might be therapeutic targets for patients with HNSCC.

First-in-Human Phase I Study of Single-agent Vanucizumab, A First-in-Class Bispecific Anti-Angiopoietin-2/Anti-VEGF-A Antibody, in Adult Patients with Advanced Solid Tumors

Purpose: Vanucizumab is an investigational antiangiogenic, first-in-class, bispecific mAb targeting VEGF-A and angiopoietin-2 (Ang-2). This first-in-human study evaluated the safety, pharmacokinetics, pharmacodynamics, and antitumor activity of vanucizumab in adults with advanced solid tumors refractory to standard therapies.Experimental Design: Patients received escalating biweekly (3-30 mg/kg) or weekly (10-30 mg/kg) intravenous doses guided by a Bayesian logistic regression model with overdose control.Results: Forty-two patients were treated. One dose-limiting toxicity, a fatal pulmonary hemorrhage from a large centrally located mediastinal mass judged possibly related to vanucizumab, occurred with the 19 mg/kg biweekly dose. Arterial hypertension (59.5%), asthenia (42.9%), and headache (31%) were the most common toxicities. Seventeen (41%) patients experienced treatment-related grade ≥3 toxicities. Toxicity was generally higher with weekly than biweekly dosing. A MTD of vanucizumab was not reached in either schedule. Pharmacokinetics were dose-linear with an elimination half-life of 6-9 days. All patients had reduced plasma levels of free VEGF-A and Ang-2; most had reductions in K^TRANS (measured by dynamic contrast-enhanced MRI). Two patients (renal cell and colon cancer) treated with 30 mg/kg achieved confirmed partial responses. Ten patients were without disease progression for ≥6 months. A flat-fixed 2,000 mg biweekly dose (phamacokinetically equivalent to 30 mg/kg biweekly) was recommended for further investigation.Conclusions: Biweekly vanucizumab had an acceptable safety and tolerability profile consistent with single-agent use of selective inhibitors of the VEGF-A and Ang/Tie2 pathway. Vanucizumab modulated its angiogenic targets, impacted tumor vascularity, and demonstrated encouraging antitumor activity in this heterogeneous population. Clin Cancer Res; 24(7); 1536-45. ©2017 AACR.

Triple-NOTE (Triple Negative Outcome in ESME): Large recent real-world prognostic data on triple negative metastatic breast cancers (mTNBC)

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Background: During last decade, therapeutic arsenal has expanded for metastatic breast cancer (mBC), but few data are available about mTNBC, a poor prognosis subtype. In 2014, UNICANCER (composed of 18 French Comprehensive Cancer Centers) launched the Epidemiological Strategy and Medical Economics (ESME) program to centralize real-world data. This base represents a great opportunity to update the outcomes and the treatment practice patterns of this population. Methods: The ESME-mBC database was built from information systems, treatment databases and patients’ electronic files including quality control processes. All pts who initiated treatment for mBC between 01-Jan-2008 and 31-Dec-2014 were selected. The primary objective of this study was to assess overall survival (OS) of mTNBC pts. TNBC status was defined as ER and PR < 10% in both primary and metastatic disease, as well as the absence of overexpression or amplification of HER2. The secondary objectives were to describe the characteristics of this population, clinical management (duration and sequence of treatments) and to evaluate the prognostic value of several clinical factors (age, distant disease free interval, location and number of metastatic sites) Results: Among 16703 pts in the ESME-mBC database, 2368 (14%) had mTNBC. Median OS over this time period was 14.8 months (95% CI 14-15.6). Median age at diagnosis of mBC was 57 years. For the pts who relapsed, median metastasis free interval was 24 months, while 25.5% of the pts were de novo metastatic. 61% of the pts presented visceral metastasis and 12% had cerebral metastasis as first metastatic site. The pattern of metastatic involvement (visceral and cerebral) and a short metastasis free interval ( < 24 months) were the most important prognostic factors in multivariate analysis. The description of treatment sequences (duration, prognostic value) will be presented. Conclusions: In this real-life setting database, mTNBC remain of poor prognosis despite a trend for a better OS than the historical data available (12-13 ms). This TNBC ESME cohort is one of the largest available and offers an updated assessment of the outcomes of this population.

SHIVA: Randomized phase II trial comparing molecularly targeted therapy based on tumor molecular profiling versus conventional therapy in patients with refractory cancer—Overall survival (OS) analysis

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Background: The SHIVA trial is a multicentric randomized phase II trial comparing molecularly targeted therapy among 11 drugs based on tumor molecular profiling versus conventional therapy in patients with any type of cancer that is refractory to standard of care (NCT01771458). Only patients who had a druggable molecular alteration (DMA) identified on a mandatory tumor sample from a metastatic site using targeted sequencing, CGH and IHC were randomized. Cross-over was allowed at disease progression. The trial did not show any difference for its primary endpoint (PFS) [Le Tourneau et al., Lancet Oncol 2015]. We report here the OS of randomized and non-randomized patients. Methods: OS was estimated in the 4 following groups: 1) randomized patients, 2) patients for whom a DMA was identified but who were not subsequently randomized because they did not meet the randomization criteria (PS of 0 or 1, adequate organ function), 3) non-randomized patients because of the absence of DMA, and 4) non-randomized patients because no genomic analyses were performed. Since 70% of patients randomized into the standard arm eventually crossed over to the targeted therapy arm, all randomized patients were analyzed in group 1. The groups were compared in terms of patient characteristics using student and χ2 tests. OS was estimated using the Kaplan Meier method. Results: Among 741 patients included in SHIVA, 8 patients were included twice. Follow-up data were available for 680 out of the 733 patients. 197, 78, 222 and 183 patients belonged to groups 1 to 4, respectively. Median OS of the whole cohort was 7.9 months [95% CI: 7.0–9.1].As compared to non-randomized patients due to the absence of identified DMA, non-randomized patients with a DMA had a significantly worse prognosis: HR = 2.3 [95% CI: 1.7–3.0] (p > 0.0001) whereas randomized patients had a non-significant trend toward a better prognosis: HR = 0.85 [95% CI: 0.7–1.1] (p = 0.18). Conclusions: A statistically significant difference in OS was only observed in patients with a DMA who were not randomized. However, our analysis does not allow showing an intrinsic prognostic value of the DMA on OS.

Cabazitaxel in recurrent/metastatic squamous cell carcinoma of the head and neck: phase II UNICANCER trial ORL03

Treatments are limited after platinum Cetuximab or anti-PD1 failure for patients with recurrent/metastatic head and neck squamous cell carcinoma. Cabazitaxel has increased overall survival in hormone-refractory metastatic prostate cancer after failure of Docetaxel. Our aim was to detect a signal of activity with Cabazitaxel in patients with head and neck cancer who had failed platinum-, Cetuximab- and taxanes-based chemotherapy.

This multicenter phase II trial included progressive patients with an ECOG ≤2. Cabazitaxel was given at 25 mg/m²/3 weeks (maximum of 10 cycles), with growth factors support. Efficacy was centralized and assessed every 6 weeks. The primary endpoint was control rate at six-weeks. A Simon’s two-stage optimal design (P0=0.10; P1=0.30) required 29 evaluable patients. At the end of trial, at least 6 non-progressions were required to consider the drug worthy of further study.

Out of the 31 enrolled patients, 29 were eligible; 42% had received at least three previous lines of chemotherapy. For the primary end point, 8 patients (27.6%; 95%CI 12.7%-47.2%) had a stable disease at six weeks. Median progression-free survival was 1.05 months (95%CI 0.69-2.07). All patients were analyzed for toxicity: 6 patients had febrile neutropenia.

During the 81 cycles administered, 49 grade 3-5 events were observed concerning 81% of the patients, including 35 severe adverse events of which 15 were related to Cabazitaxel.

Although Cabazitaxel met its primary endpoint to deserve further investigations, its toxicity makes it difficult to use in frail patients and new schemes are needed (20 mg/m² for example) if further investigations are launched.

Patient-Specific Circulating Tumor DNA Detection during Neoadjuvant Chemotherapy in Triple-Negative Breast Cancer

BACKGROUND

In nonmetastatic triple-negative breast cancer (TNBC) patients, we investigated whether circulating tumor DNA (ctDNA) detection can reflect the tumor response to neoadjuvant chemotherapy (NCT) and detect minimal residual disease after surgery.

METHODS

Ten milliliters of plasma were collected at 4 time points: before NCT; after 1 cycle; before surgery; after surgery. Customized droplet digital PCR (ddPCR) assays were used to track tumor protein p53 (TP53) mutations previously characterized in tumor tissue by massively parallel sequencing (MPS).

RESULTS

Forty-six patients with nonmetastatic TNBC were enrolled. TP53 mutations were identified in 40 of them. Customized ddPCR probes were validated for 38 patients, with excellent correlation with MPS (r = 0.99), specificity (≥2 droplets/assay), and sensitivity (at least 0.1%). At baseline, ctDNA was detected in 27/36 patients (75%). Its detection was associated with mitotic index (P = 0.003), tumor grade (P = 0.003), and stage (P = 0.03). During treatment, we observed a drop of ctDNA levels in all patients but 1. No patient had detectable ctDNA after surgery. The patient with rising ctDNA levels experienced tumor progression during NCT. Pathological complete response (16/38 patients) was not correlated with ctDNA detection at any time point. ctDNA positivity after 1 cycle of NCT was correlated with shorter disease-free (P &lt; 0.001) and overall (P = 0.006) survival.

CONCLUSIONS

Customized ctDNA detection by ddPCR achieved a 75% detection rate at baseline. During NCT, ctDNA levels decreased quickly and minimal residual disease was not detected after surgery. However, a slow decrease of ctDNA level during NCT was strongly associated with shorter survival.

Identification of new candidate therapeutic target genes in head and neck squamous cell carcinomas

BACKGROUND

We aimed at identifying druggable molecular alterations at the RNA level from untreated HNSCC patients, and assessing their prognostic significance.

METHODS

We retrieved 96 HNSCC patients who underwent primary surgery. Real-time quantitative RT-PCR was used to analyze a panel of 42 genes coding for major druggable proteins. Univariate and multivariate analyses were performed to assess the prognostic significance of overexpressed genes.

RESULTS

Median age was 56 years [35-78]. Most of patients were men (80%) with a history of alcohol (70.4%) and/or tobacco consumption (72.5%). Twelve patients (12%) were HPV-positive. Most significantly overexpressed genes involved cell cycle regulation (CCND1 [27%], CDK6 [21%]), tyrosine kinase receptors (MET [18%], EGFR [14%]), angiogenesis (PGF [301%], VEGFA [14%]), and immune system (PDL1/CD274 [28%]). PIK3CA expression was an independent prognostic marker, associated with shorter disease-free survival.

CONCLUSIONS

We identified druggable overexpressed genes associated with a poor outcome that might be of interest for personalizing treatment of HNSCC patients.

Ligand-receptor dissociated expression explains high TSLP without prognostic impact in human primary head and neck squamous cell carcinoma

Thymic stromal lymphopoietin (TSLP) is an interleukin (IL)-7-like cytokine expressed by epithelial cells during allergic inflammation, and activating dendritic cells (DC). Its expression and functional role in cancer remain controversial. We conducted retrospective (n = 89), and prospective studies including patients with untreated primary head and neck squamous cell carcinoma (HNSCC). We found that TSLP was overexpressed by HNSCC tumor cells, and associated with a highly differentiated status. However, no significant difference in overall and recurrence-free survival was found between patients bearing a tumor with high and low TSLP levels, respectively. Surprisingly, there was no significant association between the levels of TSLP expression, and the number of tumor-infiltrating mature DCLAMP(+) DC. In order to explain the apparent lack of TSLP-induced DC activation, we performed phenotypic and functional experiments on freshly resected tumors. Tumor-infiltrating immune cells, including DC, did not express the TSLP receptor heterodimer (TSLPR chain, IL-7Ralpha chain). Furthermore, freshly sorted blood CD11c(+) DC from healthy donors cultured with tumor-conditioned supernatant exhibited an activated profile, but this was not affected by an anti-TSLP blocking antibody, suggesting a DC activation pathway independent of tumor-derived TSLP. Overall, our results demonstrate that TSLP is overexpressed in HNSCC but its function is hampered by the lack of TSLPR-expressing cells in the tumor microenvironment. Such a dissociated ligand-receptor expression may impact intercellular communication in other immune activation pathways, and tumor types.

Beyond Axillary Lymph Node Metastasis, BMI and Menopausal Status Are Prognostic Determinants for Triple-Negative Breast Cancer Treated by Neoadjuvant Chemotherapy

Background

Triple-negative breast cancers (TNBC) are a specific subtype of breast cancers with a particularly poor prognosis. However, it is a very heterogeneous subgroup in terms of clinical behavior and sensitivity to systemic treatments. Thus, the identification of risk factors specifically associated with those tumors still represents a major challenge. A therapeutic strategy increasingly used for TNBC patients is neoadjuvant chemotherapy (NAC). Only a subset of patients achieves a pathologic complete response (pCR) after NAC and have a better outcome than patients with residual disease.

Purpose

The aim of this study is to identify clinical factors associated with the metastatic-free survival in TNBC patients who received NAC.

Methods

We analyzed 326 cT1-3N1-3M0 patients with ductal infiltrating TNBC treated by NAC. The survival analysis was performed using a Cox proportional hazard model to determine clinical features associated with prognosis on the whole TNBC dataset. In addition, we built a recursive partitioning tree in order to identify additional clinical features associated with prognosis in specific subgroups of TNBC patients.

Results

We identified the lymph node involvement after NAC as the only clinical feature significantly associated with a poor prognosis using a Cox multivariate model (HR = 3.89 [2.42–6.25], p<0.0001). Using our recursive partitioning tree, we were able to distinguish 5 subgroups of TNBC patients with different prognosis. For patients without lymph node involvement after NAC, obesity was significantly associated with a poor prognosis (HR = 2.64 [1.28–5.55]). As for patients with lymph node involvement after NAC, the pre-menopausal status in grade III tumors was associated with poor prognosis (HR = 9.68 [5.71–18.31]).

Conclusion

This study demonstrates that axillary lymph node status after NAC is the major prognostic factor for triple-negative breast cancers. Moreover, we identified body mass index and menopausal status as two other promising prognostic factors in this breast cancer subgroup. Using these clinical factors, we were able to classify TNBC patients in 5 subgroups, for which pre-menopausal patients with grade III tumors and lymph node involvement after NAC have the worse prognosis.

Molecularly targeted therapy based on tumour molecular profiling versus conventional therapy for advanced cancer (SHIVA): a multicentre, open-label, proof-of-concept, randomised, controlled phase 2 trial

BACKGROUND

Molecularly targeted agents have been reported to have anti-tumour activity for patients whose tumours harbour the matching molecular alteration. These results have led to increased off-label use of molecularly targeted agents on the basis of identified molecular alterations. We assessed the efficacy of several molecularly targeted agents marketed in France, which were chosen on the basis of tumour molecular profiling but used outside their indications, in patients with advanced cancer for whom standard-of-care therapy had failed.

METHODS

The open-label, randomised, controlled phase 2 SHIVA trial was done at eight French academic centres. We included adult patients with any kind of metastatic solid tumour refractory to standard of care, provided they had an Eastern Cooperative Oncology Group performance status of 0 or 1, disease that was accessible for a biopsy or resection of a metastatic site, and at least one measurable lesion. The molecular profile of each patient's tumour was established with a mandatory biopsy of a metastatic tumour and large-scale genomic testing. We only included patients for whom a molecular alteration was identified within one of three molecular pathways (hormone receptor, PI3K/AKT/mTOR, RAF/MEK), which could be matched to one of ten regimens including 11 available molecularly targeted agents (erlotinib, lapatinib plus trastuzumab, sorafenib, imatinib, dasatinib, vemurafenib, everolimus, abiraterone, letrozole, tamoxifen). We randomly assigned these patients (1:1) to receive a matched molecularly targeted agent (experimental group) or treatment at physician's choice (control group) by central block randomisation (blocks of size six). Randomisation was done centrally with a web-based response system and was stratified according to the Royal Marsden Hospital prognostic score (0 or 1 vs 2 or 3) and the altered molecular pathway. Clinicians and patients were not masked to treatment allocation. Treatments in both groups were given in accordance with the approved product information and standard practice protocols at each institution and were continued until evidence of disease progression. The primary endpoint was progression-free survival in the intention-to-treat population, which was not assessed by independent central review. We assessed safety in any patients who received at least one dose of their assigned treatment. This trial is registered with ClinicalTrials.gov, number NCT01771458.

FINDINGS

Between Oct 4, 2012, and July 11, 2014, we screened 741 patients with any tumour type. 293 (40%) patients had at least one molecular alteration matching one of the 10 available regimens. At the time of data cutoff, Jan 20, 2015, 195 (26%) patients had been randomly assigned, with 99 in the experimental group and 96 in the control group. All patients in the experimental group started treatment, as did 92 in the control group. Two patients in the control group received a molecularly targeted agent: both were included in their assigned group for efficacy analyses, the patient who received an agent that was allowed in the experimental group was included in the experimental group for the purposes of safety analyses, while the other patient, who received a molecularly targeted agent and chemotherapy, was kept in the control group for safety analyses. Median follow-up was 11·3 months (IQR 5·8-11·6) in the experimental group and 11·3 months (8·1-11·6) in the control group at the time of the primary analysis of progression-free survival. Median progression-free survival was 2·3 months (95% CI 1·7-3·8) in the experimental group versus 2·0 months (1·8-2·1) in the control group (hazard ratio 0·88, 95% CI 0·65-1·19, p=0·41). In the safety population, 43 (43%) of 100 patients treated with a molecularly targeted agent and 32 (35%) of 91 patients treated with cytotoxic chemotherapy had grade 3-4 adverse events (p=0·30).

INTERPRETATION

The use of molecularly targeted agents outside their indications does not improve progression-free survival compared with treatment at physician's choice in heavily pretreated patients with cancer. Off-label use of molecularly targeted agents should be discouraged, but enrolment in clinical trials should be encouraged to assess predictive biomarkers of efficacy.

Abstract 4523: Population pharmacokinetic (PPK) modeling of onapristone in patients (pts) with progesterone receptor (PR)-expressing cancers

Background: Onapristone is a type I PR antagonist, which prevents PR-induced DNA transcription. Onapristone anti-cancer activity is well documented. An extended-release (ER) tablet formulation of onapristone was designed to address the liver function test (LFT) elevations seen with immediate-release (IR) onapristone. A phase 1 study with onapristone in patients with tumors expressing PR is underway. Objectives included determining the PK profile of ER onapristone using a PPK approach.

Materials and methods: This is an ongoing multi-center, open-label, randomized, parallel-group, 2-stage ph1 study. Female pts ≥18 yrs with tumors expressing PR are eligible. The Stage 1 primary endpoint is the recommended ph2 dose of ER onapristone; secondary endpoints include: safety, efficacy, and PK. Pts received onapristone ER 10, 20, 30, 40 or 50 mg BID, or onapristone IR tablets 100 mg QD until progressive disease or intolerability. PK blood samples from 8 time points were collected over 12 h post-dose Day 1 for the ER and 9 blood samples over 24 h post-dose for the IR formulation. Onapristone plasma concentrations were measured using validated UPLC with tandem mass spectrometry detection (range 1-250 ng/mL). Monolix V4.1 was used to calculate absorption constant (Ka); apparent clearance (CL/F); inter-compartmental clearance (Q); apparent distribution volume (V1/F), 2nd compartment distribution volume (V2) and bioavailability (F) of ER vs IR.

Results: Stage 1 is complete. 42 pts have validated PK data. A 2-compartment open model adequately described the total onapristone time-concentration curve with linear elimination. Results are in Table 1.

Table 1.Estimated PK parameters for onapristone in pts with PR-expressing cancers (n = 42)ParameterValueRelative standard error (%)Ka0.191 h-114CL/F1.51 L/h20Q3.11 L/h25V1/F5.41 L25V241.1 L45F60%20

Conclusions: The PPK modeling described the plasma onapristone time-concentration curves well. A central volume equivalent to the circulating blood volume and a large volume of the deep compartment suggest a large tissue diffusion. PPK/PD modeling to explore safety and efficacy is ongoing, with no overt PK/safety relationship detected.

Citation Format: Keyvan Rezai, Paul Cottu, Samuel Huguet, Mario Campone, Antoine Italiano, Andrea Varga, Jacques Bonneterre, Alexandra Leary, Marie-Paule Sablin, Stefan Proniuk, Alice Bexon, Erard Gilles, Joseph Bisaha, Alexander Zukiwski, Francois Lokiec. Population pharmacokinetic (PPK) modeling of onapristone in patients (pts) with progesterone receptor (PR)-expressing cancers. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4523. doi:10.1158/1538-7445.AM2015-4523

Abstract CT331: “BEECH”, a phase I/II study of the AKT inhibitor AZD5363 combined with paclitaxel in patients with advanced or metastatic breast cancer: results from the dose-finding study, including quantitative assessment of circulating tumor DNA as a s

Background: The PI3K/AKT/MTOR pathway is frequently de-regulated in breast cancer. AZD5363 (AZD) is a potent selective inhibitor of AKT1-3. We report the dose-finding phase assessing the safety/tolerability of two intermittent weekly dosing schedules of AZD combined with paclitaxel (P) in HER2 negative breast cancer. The study incorporates prospective assessment of whether circulating tumour DNA (ctDNA) analysis can predict response/resistance earlier than conventional RECIST.

Design: AZD capsules were dosed p.o. in one of two schedules: “4/3” (4 days on-treatment followed by 3 days off, starting 360 mg twice daily (bd)) or “2/5” (2 days on-5 days off, starting 560 mg bd). Both schedules comprised 3 weeks P 90 mg/m2 IV on Day 1 with AZD started on Day 2, and 1 week off-treatment. Patients who stopped P were able to continue AZD alone at investigators’ discretion. Escalating doses of AZD were evaluated in cohorts of 3-6 evaluable patients treated until disease progression, unacceptable toxicity, or withdrawal of consent. A safety review committee reviewed safety data and dose limiting toxicities (DLTs) prior to dose modification. Plasma samples for ctDNA extraction were collected at baseline, weekly in cycle 1, day 1 of all subsequent cycles, and were analysed by digital PCR. Female patients aged ≥18 years with HER2 negative MBC and up to two prior chemotherapy courses for advanced cancer were recruited.

Results: 37 patients have received AZD. DLTs in 2/6 patients at 480 mg 4/3 comprised one patient with maculo-papular rash, and another with immune allergic reaction (both CTCAE grade 3). No DLT was observed in the 400 mg 4/3 cohort, which was defined as the maximum tolerated dose (MTD) in combination with P. DLTs in 2/6 patients at 640 mg 2/5 comprised one patient with prolonged neutropaenia (grade 4), and another with diarrhoea (grade 3). No DLTs were observed in 11 patients on the 560 mg 2/5 cohort. In all patients median progression free survival was 8.2 months, despite pre-treatment with taxane chemotherapy in 62% patients and a median of 2 prior lines of chemotherapy. A patient with Cowden's syndrome (PTEN germline mutation) had a partial response maintained for 18 months, including 12 months on AZD5363 alone. ctDNA assessment suggests that lack of a fall in ctDNA abundance may predict for early progression.

Conclusions: AZD5363 400mg bd 4/3 in combination with paclitaxel was determined to be well tolerated in patients with MBC, with investigation of the 2/5 schedule continuing. Two international double-blind randomised studies have commenced to assess AZD5363 400 mg bd 4/3 schedule combined with paclitaxel versus paclitaxel plus placebo in ER positive HER2 negative MBC stratified by PIK3CA mutation status (BEECH Part B), and in triple negative breast cancer (PAKT).

Citation Format: Nicholas C. Turner, Mafalda Oliveira, Anne Armstrong, Marie-Paule Sablin, José A. Perez-Fidalgo, Sarah Herebien, Isaac Garcia-Murillas, Stan Johnson, Andrew Foxley, Adnan Mahmood, Justin P. Lindemann. “BEECH”, a phase I/II study of the AKT inhibitor AZD5363 combined with paclitaxel in patients with advanced or metastatic breast cancer: results from the dose-finding study, including quantitative assessment of circulating tumor DNA as a s [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr CT331. doi:10.1158/1538-7445.AM2015-CT331

Abstract 4512: Onapristone in patients (pts) with progesterone receptor (PR)-expressing cancers: PK results from part 1 of a randomized, parallel-dose phase 1 study

Background:  Onapristone is a type I PR antagonist, which prevents PR-induced DNA transcription; its anti-cancer activity is well-documented. The reported T1/2 is 2-4h, so an extended-release (ER) tablet was designed to mitigate Cmax spikes, which may be involved in the liver function test (LFT) elevations seen with an immediate-release (IR) onapristone.

Materials and methods:   The expansion cohort of this multi-center, open-label, randomized, parallel-group, 2-stage Ph1 study (NCT02052128) is ongoing in endometrioid cancers. Female pts ≥18 years with PR-expressing tumors (including endometrial, ovarian, breast) were eligible. The primary endpoint was to recommend a Ph2 dose of ER onapristone (RP2D), with a 57-day DLT observation period; secondary endpoints include: safety, efficacy, and real-time PK. Pts received onapristone ER 10, 20, 30, 40 or 50 mg BID, or IR tablets 100 mg QD until progressive disease or intolerability in Stage 1.

Results: 52 pts are enrolled (by 2 December 2014). Validated PK data are available for 35 pts. Onapristone AUC and Cmax are dose-proportional across all dose levels including 100mg IR (Table 1), with coefficients of determination (r2) of 0.76 and 0.79, respectively. The bioavailability of onapristone ER vs IR is high. Steady state is consistently attained at approximately 8 days (200 h), with T1/2 at 8-12 h, longer than previously published, with no evidence of onapristone accumulation through day 57.

Table 1.Onapristone PK parameters following first doseOnapristone formERERERERERIRDose (mg)10 bid20 bid30 bid40 bid50 bid100 qdn666566Mean AUC (μg/L*h)51761765015450174403161067980CV%47.7202.722.943.070.555.1Min348029411200038091515033330Median4654860815040207302593062270Max952440000214302667062500125000Mean Cmax (μg/L)226.8676.3767.3641.614594296CV%46.0140.115.693.646.862.8Min922206762914591556Median218403732.547414953726Max4031466988134424927507

Conclusions: This study reveals a longer than anticipated onapristone T1/2, which nevertheless supports using an ER formulation. AUC and Cmax data are dose proportional and allow dosing flexibility. Protracted exposure minimizing Cmax spikes is best achieved with a twice-daily, ER formulation. There were no LFT elevations in the absence of liver metastases in 30 patients exposed to the ER formulation. The RP2D is 50 mg bid based on safety and PK, to be further explored in the endometrioid cohort.

Citation Format: Francois Lokiec, Antoine Italiano, Andrea Varga, Jacques Bonneterre, Mario Campone, Alexandra Leary, Keyvan Rezai, Marie-Paule Sablin, Alice Bexon, Stefan Proniuk, Erard Gilles, Joseph Bisaha, Alexander Zukiwski, Paul Cottu. Onapristone in patients (pts) with progesterone receptor (PR)-expressing cancers: PK results from part 1 of a randomized, parallel-dose phase 1 study. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4512. doi:10.1158/1538-7445.AM2015-4512

Disease control with sunitinib in advanced intrahepatic cholangiocarcinoma resistant to gemcitabine-oxaliplatin chemotherapy

Advanced cholangiocarcinoma is associated with poor prognostic survival and has limited therapeutic options available at present. The importance of angiogenesis and expression of pro-angiogenic factors in intrahepatic forms of cholangiocarcinoma suggest that therapies targeting angiogenesis might be useful for the treatment of this disease. Here we report three cases of patients with advanced intrahepatic cholangiocarcinoma progressive after standard chemotherapy and treated with sunitinib 50 mg/d in 6-wk cycles of 4 wk on treatment followed by 2 wk off treatment (Schedule 4/2). In all three patients, sunitinib treatment was associated with a sustained disease control superior to 4 mo, patients achieving either a partial response or stable disease. A reduction in tumor size and density was observed in all cases, suggesting tumor necrosis as a result of sunitinib treatment in these patients. In addition, sunitinib was generally well tolerated and the occurrence of side effects was managed with standard medical interventions, as required. Our results suggest that sunitinib therapy may be associated with favorable outcomes and tolerability in patients with advanced cholangiocarcinoma. Those observations contributed to launch a prospective phase II multicenter trial investigating sunitinib in advanced intrahepatic cholangiocarcinoma (SUN-CK study; NCT01718327).

The spectrum of clinical trials aiming at personalizing medicine

All anticancer molecularly targeted agents on the market today have been approved with one or no companion diagnostic based on a specific genomic molecular alteration. These drugs have followed the same clinical development than chemotherapeutic agents and have been developed in selected tumor types and histologies. Now, some molecular alterations have been described across different tumor types, although with variable prevalence and functional impact. The latter raises the question of whether treatment decision should be mainly based on molecular biology, independently of tumor location and histology. This approach refers to what is commonly named personalized medicine and can today be addressed in clinical trials, since major advances in high throughput technologies allow depicting most druggable molecular alterations for an affordable cost in a timeframe that is compatible with clinical practice. Several studies have been initiated that aim at personalizing medicine in oncology. They include molecular screening programs, as well as personalized medicine trials that can be divided in two categories: (I) stratified clinical trials according to either molecular alterations or tumor types; and (II) algorithm-testing trials evaluating a treatment algorithm instead of drugs efficacy. Multiple challenges are associated with personalized medicine trials, but the main one remains our ability to predict drug efficacy based on molecular alterations. It is expected that taking into account several molecular alterations for the prediction of drug efficacy using systems biology approaches will improve patients' outcome. Bioinformatics research will be an important factor of future progression in this emerging field.

Challenges for the implementation of high-throughput testing and liquid biopsies in personalized medicine cancer trials

During recent decades, major advances in the comprehension of biology and in biotechnologies have paved the way for what is commonly named personalized medicine. For cancer therapy, personalized medicine represents a paradigm shift in which patient treatment is based on biology in addition to histology and tumor location. Here, we report the major personalized medicine trials in oncology that are either based on molecular alterations from tumor tissue or from circulating blood markers. We next review important challenges facing the implementation of personalized medicine in daily clinical practice, including tumor heterogeneity, reliability of high-throughput technologies, the key role of bioinformatics and the assessment of biomarkers and synthetic models, in order to use big data in actual cancer biology.