scholarly journals Expanding the Use of PARP Inhibitors as Monotherapy and in Combination in Triple-Negative Breast Cancer

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.

Author(s):  
Norikazu Masuda ◽  
Hiroko Bando ◽  
Takashi Yamanaka ◽  
Takayuki Kadoya ◽  
Masato Takahashi ◽  
...  

Abstract Purpose To investigate clinical usefulness of eribulin-based neoadjuvant chemotherapy in triple-negative breast cancer (TNBC) patients. Methods Patients in group A (aged < 65 years with homologous recombination deficiency, HRD, score ≥ 42, or those at any age with germline BRCA mutation, gBRCAm) were randomized to 4 cycles of paclitaxel plus carboplatin (group A1) or eribulin plus carboplatin (group A2), followed by 4 cycles of anthracycline. Patients in group B (aged < 65 years with HRD score < 42, or aged ≥ 65 years without gBRCAm) were randomized to 6 cycles of eribulin plus cyclophosphamide (group B1) or eribulin plus capecitabine (group B2); non-responders to the first 4 cycles of the eribulin-based therapy received anthracycline. Primary endpoint was pCR rate (ypT0-is, ypN0; centrally confirmed). Main secondary endpoint was safety. Results The full analysis set comprised 99 patients. The pCR rate was 65% (90% CI, 46%–81%) and 45% (27%–65%) in groups A1 and A2, respectively, and 19% (8%–35%) in both groups B1 and B2. No major difference was seen in secondary endpoints, but peripheral neuropathy incidence was 74% in group A1, whereas it was 32%, 22%, and 26% in groups A2, B1, and B2, respectively. Conclusions In patients aged < 65 years with high HRD score or gBRCAm, weekly paclitaxel plus carboplatin and eribulin plus carboplatin followed by anthracycline resulted in a pCR rate of > 60% and > 40%, respectively, suggesting potential usefulness of patient stratification using HRD; pCR tended to be low in patients with HRD-negative tumors. Neurotoxicity was less frequent with the eribulin-based regimen. Trial registration:The study has been registered with the University Hospital Medical Information Network Clinical Trials Registry (http://www.umin.ac.jp/ctr/index-j.htm) with unique trial number UMIN000023162. The Japan Breast Cancer Research Group trial number is JBCRG-22.


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.


2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 1544-1544 ◽  
Author(s):  
Kristilyn Dillman Zonno ◽  
Rajesh R. Kaldate ◽  
Christopher Arnell ◽  
Jennifer Saam ◽  
Brian Abbott ◽  
...  

1544 Background: BRCA1/2 deleterious mutation identification among triple-negative breast cancer (TNBC) patients has gained importance due to cancer-risk management implications for patients and their relatives, and also has an emerging role in guiding treatment selection for therapies such as PARP inhibitors. The National Comprehensive Cancer Network (NCCN) currently recommends BRCA1/2 testing for TNBC patients diagnosed at age <60. Mutation prevalence among TNBC patients has previously been studied only in small regionalized cohorts. A recent study in unselected patients using the updated definitive criteria for TNBC reported mutation prevalence as 10.6%. Methods: Following the 2011 NCCN Hereditary Breast and Ovarian Cancer (HBOC) Testing Criteria update, serial cohorts of > 5,000 Ashkenazi Jewish and > 65,000 non-Ashkenazi Jewish breast cancer patients undergoing commercial BRCA1/2 testing were analyzed. Age at diagnosis, ethnicity, and provider-reported TN status were obtained from test requisition forms completed by ordering providers, and correlated with test results. Neither the accuracy nor definitive criteria used for TN status reported was independently verified. Results: Incidence of TNBC was reported as 9.7% among non-Ashkenazi patients and 16.5% within the subset with African ancestry. Incidence of TNBC was reported as 4.5% among Ashkenazi patients, but this is likely affected by test ordering for this population. The Table displays the BRCA1/2mutation rates classified by ethnicity and age-group. Conclusions: This study provides the most robust estimate to date of BRCA1/2 mutation prevalence among TNBC patients of all ages. The mutation rates seen among TNBC patients diagnosed after age 60 also illustrate the importance of testing such patients who may not meet the current NCCN HBOC testing criteria. [Table: see text]


2015 ◽  
Vol 33 (17) ◽  
pp. 1902-1909 ◽  
Author(s):  
Steven J. Isakoff ◽  
Erica L. Mayer ◽  
Lei He ◽  
Tiffany A. Traina ◽  
Lisa A. Carey ◽  
...  

Purpose The identification of patients with metastatic triple-negative breast cancer (mTNBC) who are expected to benefit from platinum-based chemotherapy is of interest. We conducted a single-arm phase II clinical trial of single-agent platinum for mTNBC with biomarker correlates. Patients and Methods Patients with mTNBC received first- or second-line cisplatin (75 mg/m2) or carboplatin (area under the concentration-time curve 6) by physician's choice once every 3 weeks. Coprimary end points were objective response rate (RR) and response prediction by p63/p73 gene expression. Secondary and exploratory end points included toxicity assessment, RR in cisplatin versus carboplatin, and RR in molecularly defined subgroups, including BRCA1/2 mutation carriers. Results Patients (N = 86; 69 as first-line therapy) received cisplatin (n = 43) or carboplatin (n = 43). RR was 25.6% (95% CI, 16.8% to 36%) and was numerically higher with cisplatin (32.6%) than with carboplatin (18.7%). RR was 54.5% in patients with germline BRCA1/2 mutations (n = 11). In patients without BRCA1/2 mutations (n = 66), exploratory analyses showed that a BRCA-like genomic instability signature (n = 32) discriminated responding and nonresponding tumors (mean homologous recombination deficiency–loss of heterozygosity/homologous recombination deficiency–large-scale state transitions [HRD-LOH/HRD-LST] scores were 12.68 and 5.11, respectively), whereas predefined analysis by p63/p73 expression status (n = 61), p53 and PIK3CA mutation status (n = 53), or PAM50 gene expression subtype (n = 55) did not. Five of the six long-term responders alive at a median of 4.5 years lacked germline BRCA1/2 mutations, and two of them had increased tumor HRD-LOH/HRD-LST scores. Conclusion Platinum agents are active in mTNBC, especially in patients with germline BRCA1/2 mutations. A measure of tumor DNA repair function may identify patients without mutations who could benefit from platinum therapy agents. Prospective controlled confirmatory trials are warranted.


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