scholarly journals PARP Inhibitor Olaparib Use in a BRCA1-Positive Patient With Metastatic Triple-Negative Breast Cancer, Without the Initial Use of Platinum-Based Chemotherapy, Showing Significant Rapid Near Resolution of Large Liver Metastasis While Patient Experienced Gout-Like Symptoms

2019 ◽  
Vol 7 ◽  
pp. 232470961986498 ◽  
Author(s):  
Trevanne Matthews Hew ◽  
Lara Zuberi

Triple-negative breast cancer (TNBC) accounts for 20% of breast cancers diagnosed worldwide. This subtype of breast cancer tends to behave more aggressively, and unlike other breast cancer subtypes, there are no standard targeted treatments for most patients. However, up to 20% of patients with TNBC harbor a breast cancer gene (BRCA) mutation, particularly in BRCA1. For patients who carry this gene mutation, this opens the door for new management options by the use of newer agents such as polyadenosine diphosphate-ribose polymerase (PARP) inhibitors in the metastatic setting. Given that this is uncommon and that PARP inhibitors have only recently received Federal Drug Administration approval, the experience with these drugs is relatively new. In this article, we present a case of a patient treated in this setting with olaparib who developed an unanticipated side effect as a result of the high efficacy of the drug.

2018 ◽  
Vol 25 ◽  
pp. 142 ◽  
Author(s):  
J.M. Lebert ◽  
R. Lester ◽  
E. Powell ◽  
M. Seal ◽  
J. McCarthy

Triple-negative breast cancer constitutes a heterogeneous group of malignancies that are often aggressive and associated with a poor prognosis. Molecular characterization, while not a standard of care, can further subtype triple-negative breast cancer and provide insight into prognostication and behaviour. Optimal chemotherapy regimens have yet to be established; however, there have been advances in the systemic treatment of triple-negative breast cancer in the neoadjuvant, adjuvant, and metastatic settings. In this review, we discuss evidence for the potential benefit of neoadjuvant platinum-based chemotherapy, adjuvant combination chemotherapy with weekly paclitaxel, and BRCA mutation–directed therapy in the metastatic setting. The role for adjuvant capecitabine in patients who do not achieve a pathologic complete response with neoadjuvant chemotherapy is reviewed. Future directions and data concerning novel targeted agents are reviewed, including the most recent data on parp [poly (adp-ribose) polymerase] inhibitors, antiandrogen agents, and immunotherapy.


2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 1063-1063 ◽  
Author(s):  
Ye Han ◽  
Chia-Wei Li

1063 Background: Poly (ADP-ribose) polymerase (PARP) inhibitors have emerged as promising targeted therapies for BRCA-mutated cancers by blocking repair of DNA double-strand breaks. However, resistance to PARP inhibitors have been described in some patients lowering overall response rates. The mechanisms underlying PARP inhibitor (PARPi) resistance are an area of active investigation. Methods: PARPi adaptive resistant clones (MDA-MB-468, MDA-MB-231, HCC1806) were generated in triple-negative breast cancer cell lines. Through morphologic observation and functional analysis, we evaluated epithelial-mesenchymal transition (EMT) and changes in immune checkpoint programmed death-ligand 1 (PD-L1). We also downregulated the expression of PD-L1 by shRNA to study the role of PD-L1 in PARPi resistance. We evaluated the immunology sensitivity to cytotoxic T cell upon PD-L1 change using a murine ex-vivo CD8+ T cell killing assay and a comparison of total killing cells percentage per well. Results: We demonstrated that inhibition of PARP enhances EMT, which induces phosphorylation of Akt at S473. This in turn upregulates the expression of PD-L1 by 2-3 fold in triple-negative breast cancer cells. In addition, PARPi–induced EMT occurred independent of PD-L1 upregulation in triple-negative breast cancer cells. Metformin administration (10µM) was found to reverse EMT by blocking the p-Akt S473 axis through activation of AMPK, resulting in downregulation of PD-L1 expression and sensitizing PARPi-resistant cancer cells to T cell killing. Conclusions: In summary, we identified that induction of EMT is a new mechanism for PARP inhibitor resistance. Metformin was able to reverse EMT and therefore a combination of metformin and PARP inhibitors may be a promising therapeutic strategy to increase the efficacy of PARP inhibitors and tumor sensitivity to T cells.


2021 ◽  
Vol 11 (10) ◽  
pp. 1009
Author(s):  
Wen-Jing Hsu ◽  
Cheng-Hsun Chen ◽  
Yu-Chu Chang ◽  
Chia-Hsiung Cheng ◽  
Ying-Huei TsaI ◽  
...  

Treatment of triple-negative breast cancer (TNBC) remains an unmet clinical need owing to its lack of an efficient therapeutic target. The targeting of DNA repair by poly(ADP-ribose) polymerase (PARP) inhibitors has shown benefit for patients with the BRCA variation. However, sensitivities to the PARP inhibitors were reported regardless of BRCA status. Thus, exploring the underlying mechanisms is imperative. Herein, we identified that breast cancer cells with an elevated expression of protein arginine methyl transferase 1 (PRMT1) was associated with therapeutic sensitivity to the PARP inhibitor olaparib. The results of cell viability and colony formation assays indicated that the suppression of PRMT1 by small hairpin RNA or by the chemical inhibitor increased sensitivity to olaparib in human TNBC MDA-MB-231 and BT549 cells. Bioinformatic analysis revealed that PRMT1 expression was significantly associated with the MYC signature, and TNBC cells with higher PRMT1 and the MYC signature were associated with therapeutic sensitivity to olaparib. Mechanistic studies further demonstrated that knockdown of PRMT1 reduced the c-Myc protein level and downregulated the expression of MYC downstream targets, whereas overexpression of PRMT1 enhanced c-Myc protein expression. Moreover, the overexpression of PRMT1 promoted c-Myc protein stability, and the inhibition of PRMT1 downregulated c-Myc protein stability. Accordingly, the knockdown of PRMT1 inhibited homologous recombination gene expression. These data indicate that PRMT1 is instrumental in regulating DNA repair, at least in part, by modulating c-Myc signaling. Our data highlighted the PRMT1/c-Myc network as a potential therapeutic target in patients with TNBC.


2021 ◽  
Vol 14 (12) ◽  
pp. 1270
Author(s):  
Mariya Yordanova ◽  
Audrey Hubert ◽  
Saima Hassan

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, and is known to be associated with a poor prognosis and limited therapeutic options. Poly (ADP-ribose) polymerase inhibitors (PARPi) are targeted therapeutics that have demonstrated efficacy as monotherapy in metastatic BRCA-mutant (BRCAMUT) TNBC patients. Improved efficacy of PARPi has been demonstrated in BRCAMUT breast cancer patients who have either received fewer lines of chemotherapy or in chemotherapy-naïve patients in the metastatic, adjuvant, and neoadjuvant settings. Moreover, recent trials in smaller cohorts have identified anti-tumor activity of PARPi in TNBC patients, regardless of BRCA-mutation status. While there have been concerns regarding the efficacy and toxicity of the use of PARPi in combination with chemotherapy, these challenges can be mitigated with careful attention to PARPi dosing strategies. To better identify a patient subpopulation that will best respond to PARPi, several genomic biomarkers of homologous recombination deficiency have been tested. However, gene expression signatures associated with PARPi response can integrate different pathways in addition to homologous recombination deficiency and can be implemented in the clinic more readily. Taken together, PARPi have great potential for use in TNBC patients beyond BRCAMUT status, both as a single-agent and in combination.


2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Wei Song ◽  
Lin Tang ◽  
Yumei Xu ◽  
Jing Xu ◽  
Wenwen Zhang ◽  
...  

Abstract Emerging evidence has shown that adding poly(ADP-ribose) polymerase (PARP) inhibitors to chemotherapy regimens is superior to the control regimens alone in BRCA1-mutated triple-negative breast cancer (TNBC) patients, but their underlying mechanisms have not been fully elucidated. In this study, using miRNA microarray analysis of two BRCA1-mutated TNBC cell lines, we found that miR-664b-5p expression was increased after adding a PARP inhibitor, olaparib, to a carboplatin (CBP) plus gemcitabine (GEM) therapy regimen. Functional assays showed miR-664b-5p overexpression inhibited proliferation, migration and invasion in BRCA1-mutated TNBC cells. CCNE2 was identified as a novel functional target of miR-664b-5p, and CCNE2 knockdown revealed effects similar to those observed with miR-664b-5p overexpression. Both CCNE2 knockdown and miR-664b-5p overexpression significantly increased the chemosensitivity of BRCA1-mutated TNBC cells. In addition, in vivo studies indicated that miR-664b-5p inhibited tumour growth compared with the control in tumour xenograft models, and we also found that CCNE2 expression was inversely correlated with miR-664b-5p expression in 90 TNBC patient samples. In conclusion, miR-664b-5p functions as a tumour suppressor and has an important role in the regulation of PARP inhibitors to increase chemosensitivity by targeting CCNE2. This may be one of the possible mechanisms by which PARP inhibitors increase chemosensitivity in BRCA1-mutated TNBC.


2021 ◽  
Vol 11 ◽  
Author(s):  
Giacomo Barchiesi ◽  
Michela Roberto ◽  
Monica Verrico ◽  
Patrizia Vici ◽  
Silverio Tomao ◽  
...  

Triple negative tumors represent 15% of breast cancer and are characterized by the lack of estrogen receptors, progesterone receptor, and HER2 amplification or overexpression. Approximately 25% of patients diagnosed with triple negative breast cancer carry a germline BRCA1 or BRCA2 mutation. They have an aggressive biology, and chemotherapy has been the mainstay of treatment for a long time. Despite intensive therapies, prognosis is still poor, and many patients will eventually relapse or die due to cancer. Therefore, novel targeted agents that can increase the treatment options for this disease are urgently needed. Recently, a new class of molecules has emerged as a standard of care for patients with triple negative breast cancer and germline BRCA1 or BRCA2 mutation: poly (ADP-ribose) (PARP) inhibitors. In the first part of the review, we summarize and discuss evidence supporting the use of PARP inhibitors. Currently, two PARP inhibitors have been approved for triple negative metastatic breast cancer—olaparib and talazoparib—based on two phase III trials, which showed a progression-free survival benefit when compared to chemotherapy. Safety profile was manageable with supportive therapies and dose reductions/interruptions. In addition, other PARP inhibitors are currently under investigation, such as talazoparib, rucaparib, and veliparib. Subsequently, we will discuss the potential role of PARP inhibitors in the future. Clinical research areas are investigating PARP inhibitors in combination with other agents and are including patients without germline BRCA mutations: ongoing phase II/III studies are combining PARP inhibitors with immunotherapy, while phases I and II trials are combining PARP inhibitors with other targeted agents such as ATM and PIK3CA inhibitors. Moreover, several clinical trials are enrolling patients with somatic BRCA mutation or patients carrying mutations in genes, other than BRCA1/2, involved in the homologous recombination repair pathway (e.g., CHECK2, PALB2, RAD51, etc.).


2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e12567-e12567
Author(s):  
Alexandra Desnoyers ◽  
Ramy Saleh ◽  
Michelle Nadler ◽  
Eitan Amir

e12567 Background: PARP inhibitors (PARPi), when given as single agents, have modest antitumor activity in patients with advanced breast cancer and germline mutation in BRCA1 or BRCA2. It is unclear whether some subgroups derive greater benefit from treatment. Methods: Two electronic databases (MEDLINE, CENTRAL) and one registry (Clinicaltrials.gov) were searched from inception to November 2018 to identify trials of PARPi in patients with metastatic breast cancer. The response rates to PARPi were extracted and pooled. Analyses were performed for patients with a germline BRCA mutation. Meta-regression explored the influence of patient and tumor characteristics and previous chemotherapy on the objective response rate (ORR) as reported in individual studies. Analysis comprised of a linear regression weighted by individual study sample size using the weighted least squares (mixed effect) method. Quantitative significance was defined using methods described by Burnand et al. Results: Of 1855 citations, 11 studies comprising 813 patients were included in the analysis. 765 (94%) patients had a germline BRCA mutations; 48% of breast cancers were triple-negative. 76% of patients had received at least 1 previous line of chemotherapy in the metastatic setting and 30% were exposed to platinum-based chemotherapy. Pooled ORR was 47% in patients with a germline BRCA mutation. Meta-regression showed that previous chemotherapy in the metastatic setting ( = -0.94, p = 0.006), especially platinum-based chemotherapy ( = -0.89, p = 0.02) were associated with highly significant negative association with ORR. A highly quantitatively significant negative association was observed for age ( = -0.80, p = 0.10), but this did not meet statistical significance. Performance status ( = 0.44, p = 0.38) and hormone receptor status (hormone receptors positive: = 0.46, p = 0.30) were not associated with response. Conclusions: PARPi therapy is associated with lesser response in patient with prior chemotherapy exposure, especially platinum-based treatment. Younger patients may benefit more from PARPi. There was no association between ORR and hormone receptor status.


Open Medicine ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. 1143-1149
Author(s):  
Meiying Shen ◽  
Huawen Pan ◽  
Yuxia Chen ◽  
Yu Hang Xu ◽  
Weixiong Yang ◽  
...  

AbstractTriple-negative breast cancer (TNBC) is a particularly aggressive subtype known for its extremely high drug resistance, progression, poor prognosis, and lack of clear therapeutic targets. Researchers are aiming to advance TNBC treatment worldwide. In the past 2–3 years, more positive results have emerged in the clinical research on TNBC treatment. Based on the results, several impressive drugs have been approved to benefit patients with TNBC, including the PARP inhibitors olaparib and talazoparib for germline BRCA mutation-associated breast cancer (gBRCAm-BC) and immunotherapy using the checkpoint inhibitor atezolizumab in combination with nab-paclitaxel for programmed cell death-ligand 1-positive (PD-L1+) advanced TNBC. Although neoadjuvant therapy has focused on combinations of systemic agents to optimize pathologically complete response, metastatic TNBC still has a poor prognosis. Innovative multidrug combination systemic therapies based on neoadjuvants and adjuvants have led to significant improvements in outcomes, particularly over the past decade.


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