Updated overall survival from the MONALEESA-3 trial in postmenopausal women with HR+/HER2- advanced breast cancer receiving first-line ribociclib plus fulvestrant.

BACKGROUND: The phase III MONALEESA-3 trial included first- (1L) and second-line (2L) patients and demonstrated a significant overall survival (OS) benefit for ribociclib + fulvestrant in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+/HER2-) advanced breast cancer (ABC) in the final protocol-specified and exploratory (longer follow-up) OS analyses. At the time of these analyses, the full OS benefit of 1L ribociclib was not completely characterized because the median OS (mOS) was not reached. As CDK4/6 inhibitor (CDK4/6i) + endocrine therapy (ET) is now a preferred option for 1L HR+/HER2- ABC, we report an exploratory analysis (median follow-up, 70.8 months; 14.5 months longer than the prior analysis) to fully elucidate the OS benefit in the MONALEESA-3 1L population. METHODS: Postmenopausal patients with HR+/HER2- ABC were randomized 2:1 to 1L/2L fulvestrant + ribociclib or placebo. OS in 1L patients (de novo disease or relapse > 12 months from completion of [neo]adjuvant ET) was assessed by Cox proportional hazards model and Kaplan-Meier methods. Progression-free survival 2 (PFS2) and chemotherapy-free survival (CFS) were analyzed. MONALEESA-3 is registered with ClinicalTrials.gov (NCT02422615). RESULTS: At data cutoff (January 12, 2022; median follow-up time, 70.8 months), mOS was 67.6 versus 51.8 months with 1L ribociclib versus placebo (hazard ratio (HR) 0.67; 95% CI 0.50-0.90); 16.5% and 8.6% of ribociclib and placebo patients, respectively, were still receiving treatment. PFS2 (HR 0.64) and CFS (HR 0.62) favored ribociclib versus placebo. Among those who discontinued treatment, 16.7% and 35.0% on ribociclib or placebo, respectively, received a subsequent CDK4/6i. No new safety signals were observed. CONCLUSIONS: This analysis of MONALEESA-3 reports the longest mOS thus far (67.6 months) for 1L patients in a phase III ABC trial. These results in a 1L population show that the OS benefit of ribociclib was maintained through extended follow-up, further supporting its use in HR+/HER2- ABC.

Early stage breast cancer follow-up in real-world clinical practice: the added value of cell free circulating tumor DNA.

PURPOSE: Physical examinations and annual mammography (minimal follow-up) are as effective as laboratory/imaging tests (intensive follow-up) in detecting breast cancer (BC) recurrence. This statement is now challenged by the availability of new diagnostic tools for asymptomatic cases. Herein, we analyzed current practices and circulating tumor DNA (ctDNA) in monitoring high-risk BC patients treated with curative intent in a comprehensive cancer center. PATIENTS AND METHODS: Forty-two consecutive triple negative BC patients undergoing neoadjuvant therapy and surgery were prospectively enrolled. Data from plasma samples and surveillance procedures were analyzed to report the diagnostic pattern of relapsed cases, i.e., by symptoms, follow-up procedures and ctDNA. RESULTS: Besides minimal follow-up, 97% and 79% of patients had at least 1 non-recommended imaging and laboratory tests for surveillance purposes. During a median follow-up of 5.1(IQR, 4.1-5.9) years, 13 events occurred (1 contralateral BC, 1 loco-regional recurrence, 10 metastases, and 1 death). Five recurrent cases were diagnosed by intensive follow-up, 5 by symptoms, and 2 incidentally. ctDNA antedated disseminated disease in all evaluable cases excepted two with bone-only and single liver metastases. The mean time from ctDNA detection to suspicious findings at follow-up imaging was 3.81(SD, 2.68), and to definitive recurrence diagnosis 8(SD, 2.98) months. ctDNA was undetectable in the absence of disease and in two suspected cases not subsequently confirmed. CONCLUSIONS: Some relapses are still symptomatic despite the extensive use of intensive follow-up. ctDNA is a specific test, sensitive enough to detect recurrence before other methods, suitable for clarifying equivocal imaging, and exploitable for salvage therapy in asymptomatic BC survivors.

Blood-based genomics of triple-negative breast cancer progression in patients treated with neoadjuvant chemotherapy.

BACKGROUND: As neoadjuvant chemotherapy (NAC) is increasingly used in triple-negative breast cancer (TNBC), we investigated the value of circulating tumor DNA (ctDNA) for patient monitoring prior, during, and after NAC, and circulating tumor cells (CTCs) for disease characterization at clinical progression. MATERIALS AND METHODS: Forty-two TNBC patients undergoing NAC were prospectively enrolled. Primary tumor mutations identified by targeted-gene sequencing were validated and tracked in 168 plasma samples longitudinally collected at multiple time-points by droplet digital polymerase chain reaction. At progression, plasma DNA underwent direct targeted-gene assay, and CTCs were collected and analyzed for copy number alterations (CNAs) by low-pass whole genome sequencing. RESULTS: ctDNA detection after NAC was associated with increased risk of relapse, with 2-year event-free survival estimates being 44.4% [95% confidence interval (CI) 21.4%-92.3%] versus 77.4% (95% CI 57.8%-100%). ctDNA prognostic value remained worthy even after adjusting for age, residual disease, systemic inflammatory indices, and Ki-67 [hazard ratio (HR) 1.91; 95% CI 0.51-7.08]. During follow-up, ctDNA was undetectable in non-recurrent cases with the unique exception of one showing a temporary peak over eight samples. Conversely, ctDNA was detected in 8/11 recurrent cases, and predated the clinical diagnosis up to 13 months. Notably, recurrent cases without ctDNA developed locoregional, contralateral, and bone-only disease. At clinical progression, CTCs presented chromosome 10 and 21q CNAs whose network analysis showed connected modules including HER/PI3K/Ras/JAK signaling and immune response. CONCLUSION: ctDNA is not only associated with but is also predictive of prognosis in TNBC patients receiving NAC, and represents an exploitable tool, either alone or with CTCs, for personalized TNBC management.

De-escalated therapy for HR+/HER2+ breast cancer patients with Ki67 response after 2-week letrozole: results of the PerELISA neoadjuvant study.

BACKGROUND: In human epidermal growth factor receptor 2 (HER2+) breast cancers, neoadjuvant trials of chemotherapy plus anti-HER2 treatment consistently showed lower pathologic complete response (pCR) rates in hormone receptor (HR) positive versus negative tumors. The PerELISA study was aimed to evaluate the efficacy of a de-escalated, chemotherapy-free neoadjuvant regimen in HR+/HER2+ breast cancer patients selected on the basis of Ki67 inhibition after 2-week letrozole. PATIENTS AND METHODS: PerELISA is a phase II, multicentric study for postmenopausal patients with HR+/HER2+ operable breast cancer. Patients received 2-week letrozole, and then underwent re-biopsy for Ki67 evaluation. Patients classified as molecular responders (Ki67 relative reduction >20% from baseline) continued letrozole and started trastuzumab-pertuzumab for five cycles. Patients classified as molecular non-responders started weekly paclitaxel for 13 weeks combined with trastuzumab-pertuzumab. Primary aim was breast and axillary pCR. According to a two-stage Simon's design, to reject the null hypothesis, at least 8/43 pCR had to be documented. RESULTS: Sixty-four patients were enrolled, 44 were classified as molecular responders. All these patients completed the assigned treatment with letrozole-trastuzumab-pertuzumab and underwent surgery. A pCR was observed in 9/44 cases (20.5%, 95% confidence interval 11.1% to 34.5%). Among molecular non-responders, 16/17 completed treatment and underwent surgery, with pCR observed in 81.3% of the cases. PAM50 intrinsic subtype was significantly associated with Ki67 response and pCR. Among molecular responders, the pCR rate was significantly higher in HER2-enriched than in other subtypes (45.5% versus 13.8%, P = 0.042). CONCLUSIONS: The primary end point of the study was met, by reaching the pre-specified pCRs. In patients selected using Ki67 reduction after short-term letrozole exposure, a meaningful pCR rate can be achieved without chemotherapy. PAM50 intrinsic subtyping further refines our ability to identify a subset of patients for whom chemotherapy might be spared. EUDRACT NUMBER: 2013-002662-40. CLINICALTRIALS.GOV IDENTIFIER: NCT02411344.

Efficacy and safety of Everolimus and Exemestane in hormone-receptor positive (HR+) human-epidermal-growth-factor negative (HER2-) advanced breast cancer patients: New insights beyond clinical trials. The EVA study.

BACKGROUND: The BOLERO-2 trial reported efficacy and safety of Everolimus (EVE) and Exemestane (EXE) combination in HR+ advanced breast cancer (ABC) patients. The BALLET trial further evaluated the safety of EVE-EXE in HR+ ABC patients, without reporting efficacy data. Aim of the EVA real-life study was to collect data of efficacy and safety of EVE-EXE combination in the clinical setting, as well as exploring efficacy according to EVE Dose-Intensity (DI) and to previous treatment with Fulvestrant. PATIENTS AND METHODS: This study aimed to describe the outcome of ABC pts treated with EVE-EXE combination in terms of median duration of EVE treatment and ORR in a real-life setting. RESULTS: From July 2013 to December 2015, the EVA study enrolled 404 pts. Median age was 61 years (33-83). Main metastatic sites were: bone (69.1%), soft tissue (34.7%) and viscera (33.2%). Median number of previous treatments was 2 (1-7). 43.3% of the pts had received Fulvestrant. Median exposure to EVE was 31.0 weeks (15.4-58.3) in the whole population. No difference was observed in terms of EVE exposure duration according to DI (p for trend = 0.27) or type of previous treatments (p = 0.33). ORR and Disease Control Rate (DCR) were observed in 31.6% and 60.7% of the patients, respectively, with the lowest ORRs confined in CHT pre-treated patients or in those who received the lowest DI of EVE. Grade 3-4 adverse events (AEs) were reported in 37.9% of the patients. Main AEs were: stomatitis (11.2%), non-infectious pneumonitis - NIP (3.8%), anaemia (3.8%) and fatigue (3.2%). CONCLUSIONS: The EVA study provided new insights in the use of EVE-EVE combination in HR+ ABC pts many years after the publication of the pivotal trial. The combination is safe and the best response could be obtained in patients receiving the full dose of EVE and/or after hormone-therapy as Fulvestrant in ABC.

Immune modulation of pathologic complete response after neoadjuvant HER2-directed therapies in the NeoSphere trial.

BACKGROUND: To investigate in the NeoSphere trial the contribution of the immune system to pathologic complete response in the breast (pCRB) after neoadjuvant docetaxel with trastuzumab (TH), pertuzumab (TP), or both (THP), or monoclonal antibodies alone (HP). PATIENTS AND METHODS: Immune gene mRNA expression (n = 350, 83.8%), lymphocyte infiltration (TIL, n = 243, 58.3%), and PDL1 by immunohistochemistry (n = 305, 73.1%) were correlated with pCRB. We studied five selected genes (IFNG, PD1, PDL1, PDL2, CTLA4) and six immune metagenes corresponding to plasma cells (IGG), T cells (CD8A), antigen-presenting cells (MHC2), and to MHC1 genes (MHC1), STAT1 co-expressed genes (STAT1), and interferon-inducible genes (IF-I). Gene expression data from the NOAH trial were used for validation. RESULTS: TIL as continuous variable and PDL1 protein expression were not significantly associated with pCRB. Expression of immune genes/metagenes had different association with pCRB after THP than after other therapies. With THP, higher expression of PD1 and STAT1, or any among PDL1, CTLA4, MHC1, and IF-I were linked with lower pCRB. In the combined TH/TP/HP treatment group, in multivariate analysis, higher expression of PD1, MHC2, and STAT1 were linked with pCRB, and higher PDL1, MHC1, or IF-I to lower pCRB. In the NOAH, a similar association of higher STAT1 with higher pCRB, and higher MHC1 and IF-I with lower pCRB was found for trastuzumab/chemotherapy but not for chemotherapy treatment only. CONCLUSIONS: The immune system modulates response to therapies containing trastuzumab and pertuzumab. Greatest benefit from THP is observed for low expression of some immune markers (i.e. MHC1, CTLA4). The involvement of PDL1 in resistance supports testing combinations of HER2-directed antibodies and immune-checkpoint inhibitors.