Buparlisib in Kombination mit Tamoxifen: Rationale für zielgerichtete Therapie bei PIK3CA-mutiertem metastasierten Mammakarzinom bestätigt

2021 ◽  
pp. 1-3
Author(s):  
Carlota Claussen ◽  
Maggie Banys-Paluchowski

The PIKTAM study evaluated the efficacy and safety of the PI3K inhibitor buparlisib in combination with tamoxifen in hormone receptor-positive (HR+), HER2-negative advanced breast cancer patients after failure of prior endocrine therapy. In this open-label, single-arm phase II trial, 25 patients were enrolled in 11 sites in Germany. Patients were stratified according to PIK3CA mutation status (tissue and cfDNA from serum samples) and/or loss of PTEN expression. Patients received buparlisib (100mg) and tamoxifen (20mg) once daily on a continuous schedule (28-day cycle) until progression or unacceptable toxicity. Primary endpoint was overall 6-month progression-free survival (PFS) rate. Key secondary endpoints included the 6-month PFS rate in subpopulations, PFS, overall survival, overall response rate (ORR), disease control rate (DCR), and safety. Overall, the 6-month PFS rate was 33.3% (n/N = 7/21, one-sided 95% CI 16.8–100) and median PFS was 6.1 (CI 2.6–10.6) months. The ORR and DCR were 12.5% and 44%. The PIK3CA-mutated subgroup consistently showed the highest 6-month PFS rate (62.5%, n/N = 5/8), median PFS (8.7 months), ORR (40%), and DCR (80%). No new safety signals emerged. Most common adverse events were gastrointestinal disorders (56%), psychiatric/mood disorders (48%), skin rash/hypersensitivity (44%), cardiovascular (40%), and hepatic (32%) events. The trial was prematurely terminated due to the substantially altered risk – benefit profile of buparlisib. Nevertheless, PIK3CA mutations emerged as a clinically feasible and useful biomarker for combined PI3K inhibition and endocrine therapy in patients with HR+ breast cancer. Further biomarker – stratified studies with isoform – specific PI3K inhibitors are warranted. EudraCT No: 2014–000599–24.

2020 ◽  
Vol 12 ◽  
pp. 175883592094093 ◽  
Author(s):  
Pauline du Rusquec ◽  
Cyriac Blonz ◽  
Jean Sebastien Frenel ◽  
Mario Campone

Recently many therapeutic classes have emerged in advanced hormone receptor-positive breast cancer, which is the leading cause of cancer death in women. In absence of visceral crisis, treatment relies on endocrine therapy combined with cyclin dependent kinase 4 and 6 inhibitor. Many mechanisms lead to resistance to endocrine therapy, including the activation of intracellular signaling pathways critical for cell survival. Approximately 70% of breast tumors harbor an alteration in the phosphoinositide 3 kinase (PI3K)/Akt pathway, leading to its hyper activation. This pathway is involved in the regulation of growth, proliferation and cell survival as well as in angiogenesis and is consequently a major target in the oncogenesis. An aberrant PIK3CA mutation is a common phenomenon in breast cancer and found in approximately 40% of patients with advanced hormone receptor-positive breast cancer. For the moment, the only positive trials showing a progression free survival benefit in this population are BOLERO-2 (2012), SOLAR-1 (2019), which tested everolimus, a mammalian target of rapamycin inhibitor, and alpelisib, a PI3K inhibitor, and led to their marketing authorization. However, many other inhibitors of this pathway are promising; nevertheless their development is actually limited by toxicity, mainly cutaneous (rash), digestive (diarrhea) and endocrine (diabetes).


2020 ◽  
Vol 3 (3) ◽  
pp. 133-136
Author(s):  
Elias A. Chandran ◽  
Ian Kennedy

ABSTRACT PIK3CA mutations resulting in disinhibition of the phosphoinositide 3-kinase (PI3K) pathway are present in approximately a third of estrogen receptor (ER)-positive breast cancer. Recent clinical trials of PI3K inhibition in PIK3CA-mutated metastatic breast cancer have shown improvement in progression-free survival of up to 11 months. We report a 68-year-old woman with metastatic ER-positive breast cancer with PIK3CA mutation who despite having disease progression after four lines of endocrine therapy (ET) attained a complete response (CR) after subsequent addition of a PI3K inhibitor. Remarkably, her CR is still maintained at 5 years. We believe this may be due to the co-occurrence of an NF1 mutation, which increases sensitivity to PI3K inhibition. Our case demonstrates restoration of sensitivity to ET by additional inhibition of PI3K, which resulted in exceptional disease response, far exceeding the expected duration. Hence, we believe that PI3K inhibition in addition to ET should be considered in patients with simultaneous PIK3CA and NF1 mutations.


2021 ◽  
Vol 13 ◽  
pp. 175883592098765
Author(s):  
Raffaella Palumbo ◽  
Rosalba Torrisi ◽  
Federico Sottotetti ◽  
Daniele Presti ◽  
Anna Rita Gambaro ◽  
...  

Background: The CDK4/6 inhibitor palbociclib combined with endocrine therapy (ET) has proven to prolong progression-free survival (PFS) in women with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2−) metastatic breast cancer (MBC). Few data are available regarding the efficacy of such a regimen outside the clinical trials. Patients and methods: This is a multicentre prospective real-world experience aimed at verifying the outcome of palbociclib plus ET in an unselected population of MBC patients. The primary aim was the clinical benefit rate (CBR); secondary aims were the median PFS, overall survival (OS) and safety. Patients received palbociclib plus letrozole 2.5 mg (cohort A) or fulvestrant 500 mg (cohort B). Results: In total, 191 patients (92 in cohort A, 99 in cohort B) were enrolled and treated, and 182 were evaluable for the analysis. Median age was 62 years (range 47–79); 54% had visceral involvement; 28% of patients had previously performed one treatment line (including chemotherapy and ET), 22.6% two lines and 15.9% three. An overall response rate of 34.6% was observed with 11 (6.0%) complete responses and 52 (28.6%) partial responses. Stable disease was achieved by 78 patients (42.9%) with an overall CBR of 59.8%. At a median follow-up of 24 months (range 6–32), median PFS was 13 months without significant differences between the cohorts. When analysed according to treatment line, PFS values were significantly prolonged when palbociclib-based therapy was administered as first-line treatment (14.0 months), to decrease progressively in second and subsequent lines (11.7 and 6.7 months, respectively). Median OS was 25 months, ranging from 28.0 months in 1st line to 18.0 and 13.0 months in 2nd and subsequent lines, respectively. Conclusions: Our data indicate that palbociclib plus ET is active and safe in HR+/HER2− MBC, also suggesting a better performance of the combinations in earlier treatment lines.


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 1087-1087
Author(s):  
Tao Sun ◽  
Yanxia Shi ◽  
Jiuwei Cui ◽  
Yongmei Yin ◽  
Quchang Ouyang ◽  
...  

1087 Background: Breast cancer is the most common cancer among women, with up to 37% of patients (pts) harboring germline BRCA1/2 mutations (g BRCA1/2m) that appear to be sensitive to poly (ADP-ribose) polymerase proteins 1 and 2 (PARP1/2) inhibition. Pamiparib is an orally administered selective PARP1/2 inhibitor that has the potential to cross the blood-brain barrier. This study evaluated the efficacy and safety of pamiparib in pts with locally advanced/metastatic human epidermal growth factor receptor 2-negative (HER2-) breast cancer, with deleterious or suspected deleterious g BRCA1/2m, who received ≤ 2 prior lines of chemotherapy. Methods: In this open-label, phase 2, multi-center study in China (NCT03575065), pts with locally advanced/metastatic HER2- breast cancer with deleterious or suspected deleterious g BRCA1/2m triple negative breast cancer (TNBC cohort) or hormone receptor-positive (HR+)/HER2- breast cancer (HR+ cohort) were enrolled. Pts received pamiparib 60 mg orally twice daily in 28-day cycles. The primary endpoint was objective response rate (ORR; RECIST v1.1) by independent review committee (IRC). Secondary endpoints included duration of response (DOR) and progression free survival (PFS) by IRC, overall survival (OS), safety and tolerability. Results: 88 pts were enrolled (median age 45.5 years), 76 pts (TNBC cohort n = 55; HR+ cohort n = 21) had measurable disease at baseline per IRC. 60 pts (68.2%) received 1 or 2 prior lines of chemotherapy; 42 pts (47.7%) were treated with platinum previously. Median follow-up was 13.77 months (TNBC cohort, 10.87 months; HR+ cohort, 18.45 months). In the TNBC cohort: confirmed ORR was 38.2% (95% CI: 25.4–52.3); median DOR (mDOR) was 6.97 months (95% CI: 3.94–not estimable[NE]); median PFS (mPFS) was 5.49 months (95% CI: 3.65–7.33); median OS (mOS) was 17.08 months (95% CI:13.70–NE). In the HR+ cohort: confirmed ORR was 61.9% (95% CI: 38.4–81.9); mDOR was 7.49 months (95% CI: 5.55–14.75); mPFS was 9.20 months (95% CI: 7.39–11.93); mOS was not reached (NR; 95% CI 18.10–NE). ≥ Grade 3 treatment emergent adverse events (TEAEs) occurred in 54 pts (61.4%); anemia was the most common TEAE, occurring in 77 pts (87.5%). Dose reduction due to TEAEs occurred for 57 pts (64.8%); discontinuations due to TEAEs occurred for 2 pts (2.3%). Conclusions: Pamiparib showed a promising response in pts with locally advanced/metastatic HER2- breast cancer with a g BRCA1/2m. The safety profile of pamiparib was considered acceptable and was generally consistent with therapies in the same class. Clinical trial information: NCT03575065 .[Table: see text]


2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e22065-e22065 ◽  
Author(s):  
R. Wesolowski ◽  
A. G. Shealy ◽  
J. Tao ◽  
H. C. Moore

e22065 Background: Mutations in BRCA1 and BRCA2 genes lead to defects in DNA repair. Estrogen receptor modulates transcription of genes responsible for cell division, which depends on cell's ability to repair DNA for genomic integrity. Differential efficacy of endocrine therapy for breast cancer, therefore, may be possible depending on the tumor's BRCA mutation status. Methods: Through an IRB approved registry, breast cancer patients tested for BRCA1 and BRCA2 mutations and treated with endocrine therapy for hormone-receptor positive non-metastatic disease were identified. Primary and secondary endpoints were overall survival (OS) and progression-free survival (PFS) respectively. Fisher's exact test or Wilcoxon rank sum test were used to assess differences among subgroups with respect to their characteristics. Cox proportional hazard analysis was used to identify univariate and multivariate risk factors for OS and PFS. Results: Of 115 breast cancer patients tested for BRCA mutations, 63 met the inclusion criteria of whom 16 patients were BRCA 1 or 2 mutation positive and 47 were negative. In the BRCA(+) group, 14 patients (87.5%) had stage I-III disease at diagnosis. In the BRCA(-) group, 5 patients (10.6%) had stage 0 disease while 41 patients (87.2%) had stage I-III disease at diagnosis. Stage at diagnosis was unavailable for 2 BRCA(+) and 1 BRCA(-) patients. Both groups were similar with respect to Her-2 expression status, history of ovarian suppression, age of diagnosis, and age of menopause. Median age was 48 yo in BRCA(+) group, 42 yo in BRCA(-), (p=0.12). Median follow up was 76.1 mos in BRCA(+) and 62.9 mos in BRCA(-) group. OS was worse in BRCA(+) group (HR 7.38, 95% [CI] 1.49–36.4 p=0.014). After adjustment for stage and history of ovarian suppression, the difference remained significant (HR 16.6, 95% [CI] 1.95–142, p=0.010). There was no difference in PFS (HR 2.02, 95% [CI] 0.82–4.96, p=0.13). Conclusions: Patients with BRCA mutation, hormone-receptor positive hereditary breast cancer treated with endocrine therapy had inferior survival compared with similar patients who are BRCA mutation negative. Prospective studies to evaluate the differential effects of endocrine therapy in these populations are warranted. No significant financial relationships to disclose.


2012 ◽  
Vol 30 (15_suppl) ◽  
pp. TPS652-TPS652
Author(s):  
Ahmad Awada ◽  
Javier Cortes ◽  
Miguel Martin ◽  
Philippe Aftimos ◽  
Mafalda Oliveira ◽  
...  

TPS652 Background: Hormone receptor-positive, HER2-negative breast cancer (BC) is currently associated with 3-4 years overall survival in the metastatic setting and, after ≥2 relapses, therapeutic approaches are reduced. XPG expression is frequently modified in BC. T is a cytotoxic agent that forms a complex with the XPG, inducing cell apoptosis. As a single agent, T has shown anti-tumor activity in patients with poor prognosis BC, and a better response to T in BC patients with XPG RNA overexpression has been observed. Methods: This is an open-label, phase II study of T (1.3 mg/m2 in 3-hour intravenous infusion every 3 weeks) in patients with hormone receptor-positive, HER2-negative advanced BC, according to their primary tumor’s XPG expression. Primary endpoint: to evaluate the efficacy of T in terms of progression free survival rate at 4 months (PFS4) according to the patient’s XPG expression. Secondary endpoints: Comparison of PFS, overall response rate, duration of response, overall survival and safety profile in XPG-high and XPG-low patients. Assignment: BC patients who have previously received anthracyclins and/or taxanes and who progressed after 2-5 chemotherapy lines will be assigned according to their XPG expression from paraffin embedded tumor samples to stratum A (XPG-high [>3]) or to stratum B (XPG-low [≤3]) (threshold was selected from median XPG expression values observed in a previous trial). Statistical methods: A two-stage design was chosen: at a first stage 20 patients will be enrolled in each stratum. A futility analysis (O’Brien Fleming boundary) based on the primary endpoint (PFS4) will be conducted once 40 evaluable patients have been recruited. If ≥ 7 out of 20 patients achieve PFS4, recruitment will continue to a maximum sample size of 50 evaluable patients per stratum. If ≥ 22 out of 50 patients achieve PFS4, T will be considered active in this group (alpha error: 0.025, power: 80%). To date, 35 patients (16 XPG-high and 15 XPG-low) have been enrolled from three countries and five centers. Recruitment is ongoing.


2019 ◽  
Vol 37 (15_suppl) ◽  
pp. TPS1115-TPS1115 ◽  
Author(s):  
Romualdo Barroso-Sousa ◽  
Lorenzo Trippa ◽  
Paulina Lange ◽  
Chelsea Andrews ◽  
Heather L. McArthur ◽  
...  

TPS1115 Background: A previous study from our group showed that approximately 9% of metastatic breast cancer (MBC) is hypermutated, defined as a tumor mutational burden (TMB) ≥10 Mutations/Megabase (Mut/Mb). The aim of this study is to evaluate if patients with hypermutated HER2-negative MBC benefit from the combination of nivolumab plus ipilimumab. Methods: This is an open-label, single-arm, multicenter, phase 2 study assessing the efficacy of nivolumab 3 mg/Kg intravenously (IV) every 14 days plus Ipilimumab 1 mg/Kg IV every 6 weeks in subjects with hypermutated metastatic HER2-negative breast cancer. Patients with measurable HER2-negative MBC, TMB ≥10 Mut/Mb assessed by a cancer-gene panel evaluating > 300 genes and performed in a CLIA-certified laboratory, and 0-3 prior lines of chemotherapy in the advanced setting are eligible. The primary objective is overall response rate according to RECIST 1.1. Secondary objectives include the safety and tolerability of the combination, progression-free survival, and overall survival. The study will follow a two-stage design. In the first stage 14 patients will be enrolled. If there is at least one patient with objective response, accrual will continue to the second stage where an additional 16 patients will be enrolled. If there are at least 4 patients with an objective response among the 30 patients, the regimen will be considered worthy of further study. If the true response rate is 5%, the chance the regimen is declared worthy of further study is less than 5%. If the true response rate is 25%, the chance that the regimen is declared worthy of further study is > 90%. Tumor biopsies, peripheral blood, and stool collection are mandatory and will be obtained at baseline, on treatment (end of cycle 1), and at disease progression and will be assessed for potential biomarkers of treatment response. The trial was activated in February 2019, and accrual should be completed in 18 months. Clinical trial information: NCT03789110.


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