Veliparib with temozolomide or carboplatin/paclitaxel versus placebo with carboplatin/paclitaxel in patients with BRCA1/2 locally recurrent/metastatic breast cancer: randomized phase II study

Targeting the DNA damage response: PARP inhibitors and new perspectives in the landscape of cancer treatment

Cancer derives from alterations of pathways responsible for cell survival, differentiation and proliferation. Dysfunctions of mechanisms protecting genome integrity can promote oncogenesis but can also be exploited as therapeutic target. Poly-ADP-Ribose-Polymerase (PARP)-inhibitors, the first approved targeted agents able to tackle DNA damage response (DDR), have demonstrated antitumor activity, particularly when homologous recombination impairment is present. Despite the relevant results achieved, a large proportion of patients fail to obtain durable responses. The development of innovative treatments, able to overcome resistance and ensure long-lasting benefit for a wider population is still an unmet need. Moreover, improvement in biomarker assays is necessary to properly identify patients who can benefit from DDR targeting agents. Here we summarize the main DDR pathways, explain the current role of PARP inhibitors in cancer therapy and illustrate new therapeutic strategies targeting the DDR, focusing on the combinations of PARP inhibitors with other agents and on cell-cycle checkpoint inhibitors.

Impact of Value Frameworks on the Magnitude of Clinical Benefit: Evaluating a Decade of Randomized Trials for Systemic Therapy in Solid Malignancies

In the era of rapid development of new, expensive cancer therapies, value frameworks have been developed to quantify clinical benefit (CB). We assessed the evolution of CB since the 2015 introduction of The American Society of Clinical Oncology and The European Society of Medical Oncology value frameworks. Randomized clinical trials (RCTs) assessing systemic therapies for solid malignancies from 2010 to 2020 were evaluated and CB (Δ) in 2010–2014 (pre-value frameworks (PRE)) were compared to 2015–2020 (POST) for overall survival (OS), progression-free survival (PFS), response rate (RR), and quality of life (QoL). In the 485 studies analyzed (12% PRE and 88% POST), the most common primary endpoint was PFS (49%), followed by OS (20%), RR (12%), and QoL (6%), with a significant increase in OS and decrease in RR as primary endpoints in the POST era (p = 0.011). Multivariable analyses revealed significant improvement in ΔOS POST (OR 2.86, 95% CI 0.46 to 5.26, p = 0.02) while controlling for other variables. After the development of value frameworks, median ΔOS improved minimally. The impact of value frameworks has yet to be fully realized in RCTs. Efforts to include endpoints shown to impact value, such as QoL, into clinical trials are warranted.

BRCA1 Versus BRCA2 and PARP Inhibitors Efficacy in Solid Tumors:A Meta-Analysis of Randomized Controlled Trials

Background

BRCA2 mutation has a more substantial impact on the homologous recombination and superior therapeutic response to platinum-based chemotherapy than BRCA1 mutation. Whether BRCA2-mutated patients could benefit more from PARPi than BRCA1-mutated patients remains unclear. We performed a meta-analysis to assess the efficacy difference of PARPi between BRCA1 mutation carriers and BRCA2 mutation carriers.

Methods

Pubmed, Embase, and Cochrane Library were comprehensively searched for randomized controlled trials (RCTs) of PARPi that had available hazard ratios (HRs) of progression-free survival (PFS) in both BRCA1-mutated population and BRCA2-mutated population. We calculated the pooled PFS HRs and 95%CI using randomized-effect models, and the difference between the two estimates was compared by interaction test.

Results

A total of 11 eligible RCTs of high quality were identified through search. Overall, 1544 BRCA1 mutation carriers and 1191 BRCA2 mutation carriers were included in the final analysis. The pooled PFS HR was 0.42 (95% CI: 0.35-0.50) in BRCA1-mutated patients who were treated with PARPi compared with patients in the control group. In BRCA2-mutated patients treated with PARPi, the pooled PFS HR compared with the control groups was 0.35 (95% CI: 0.24-0.51). The difference in efficacy of PARPi was not significant between the two subgroups (P _{heterogeneity} = 0.40, for interaction).

Conclusion

BRCA1-mutated patients and BRCA2-mutated patients could benefit from PARPi, and the efficacy is comparable. Currently, there is no evidence that BRCA2-mutated patients would benefit more from PARPi than BRCA1-mutated patients.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42020214582.

Efficacy and Safety of PARP Inhibitors in Advanced or Metastatic Triple-Negative Breast Cancer: A Systematic Review and Meta-Analysis

Purpose

Poly (ADP-ribose) polymerase (PARP) inhibitors have shown promising results in metastatic triple-negative breast cancers (TNBCs). We therefore performed a systematic review and meta-analysis to evaluate the efficacy and safety of this drug in patients with advanced or metastatic TNBC.

Methods

A systematic literature search of PubMed, Embase, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials for synonyms of "PARP inhibitors" and "breast cancer" was carried out. All published phase II/III clinical studies of PARP inhibitors in patients with advanced/metastatic TNBC were screened. Data were extracted independently by two authors and analyzed using Review Manager software version 5.3. End points include overall response rate (ORR), progression-free survival (PFS), and adverse events.

Results

Ten clinical trials were identified, with a total of 1,495 patients included. Pooled analyses showed that PARP inhibitors could provide a significant improvement of ORR [risk ratio (RR) = 2.00; 95% confidence interval (CI), 1.14-3.50; p = 0.02) and PFS [hazard ratio (HR) = 0.68; 95%Cl, 0.59-0.77; p < 0.0001) compared to chemotherapy in the whole population. In subgroup analysis, patients with BRCA mutation had a higher objective response to PARP inhibitor, with an RR of 2.85 (95%CI, 1.34-6.06; p = 0.007) compared to BRCA wild-type patients. However, no significant difference in ORR was observed between the homologous recombination deficiency (HRD) positive and non-HRD subgroups (RR = 1.82; 95%CI, 0.81-4.08; p = 0.14). Hematological toxicity is a common adverse event of PARP inhibitors.

Conclusions

PARP inhibitors are effective options for the treatment of patients with advanced or metastatic TNBC. Compared with patients without germline BRCA mutation, patients with germline BRCA mutation could benefit more from PARP inhibitors. In clinical setting, hematological toxicity associated with PARP inhibitors should be monitored regularly.

Veliparib in Combination With Platinum-Based Chemotherapy for First-Line Treatment of Advanced Squamous Cell Lung Cancer: A Randomized, Multicenter Phase III Study

PURPOSE

Squamous non-small-cell lung cancer (sqNSCLC) is genetically complex with evidence of DNA damage. This phase III study investigated the efficacy and safety of poly (ADP-ribose) polymerase inhibitor veliparib in combination with conventional chemotherapy for advanced sqNSCLC (NCT02106546).

PATIENTS AND METHODS

Patients age ≥ 18 years with untreated, advanced sqNSCLC were randomly assigned 1:1 to carboplatin and paclitaxel with veliparib 120 mg twice daily (twice a day) or placebo twice a day for up to six cycles. The primary end point was overall survival (OS) in the veliparib arm versus the control arm in current smokers, based on phase II findings. Archival tumor samples were provided for biomarker analysis using a 52-gene expression histology classifier (LP52).

RESULTS

Overall, 970 patients were randomly assigned to carboplatin and paclitaxel plus either veliparib (n = 486) or placebo (n = 484); 57% were current smokers. There was no significant OS benefit with veliparib in current smokers, with median OS 11.9 versus 11.1 months (hazard ratio [HR], 0.905; 95% CI, 0.744 to 1.101; P = .266). In the overall population, OS favored veliparib; median OS was 12.2 versus 11.2 months (HR, 0.853; 95% CI, 0.747 to 0.974), with no difference in progression-free survival (median 5.6 months per arm). In patients with biomarker-evaluable tumor samples (n = 360), OS favored veliparib in the LP52-positive population (median 14.0 v 9.6 months; HR, 0.66; 95% CI, 0.49 to 0.89), but favored placebo in the LP52-negative population (median 11.0 v 14.4 months; HR, 1.33; 95% CI, 0.95 to 1.86). No new safety signals were observed in the experimental arm.

CONCLUSION

In current smokers with advanced sqNSCLC, there was no therapeutic benefit of adding veliparib to first-line chemotherapy. The LP52 signature may identify a subgroup of patients likely to derive benefit from veliparib with chemotherapy.

Role of PARP in TNBC: Mechanism of Inhibition, Clinical Applications, and Resistance

Triple-negative breast cancer is a combative cancer type with a highly inflated histological grade that leads to poor theragnostic value. Gene, protein, and receptor-specific targets have shown effective clinical outcomes in patients with TNBC. Cells are frequently exposed to DNA-damaging agents. DNA damage is repaired by multiple pathways; accumulations of mutations occur due to damage to one or more pathways and lead to alterations in normal cellular mechanisms, which lead to development of tumors. Advances in target-specific cancer therapies have shown significant momentum; most treatment options cause off-target toxicity and side effects on healthy tissues. PARP (poly(ADP-ribose) polymerase) is a major protein and is involved in DNA repair pathways, base excision repair (BER) mechanisms, homologous recombination (HR), and nonhomologous end-joining (NEJ) deficiency-based repair mechanisms. DNA damage repair deficits cause an increased risk of tumor formation. Inhibitors of PARP favorably kill cancer cells in BRCA-mutations. For a few years, PARPi has shown promising activity as a chemotherapeutic agent in BRCA1- or BRCA2-associated breast cancers, and in combination with chemotherapy in triple-negative breast cancer. This review covers the current results of clinical trials testing and future directions for the field of PARP inhibitor development.

Breast cancer treatment-related cardiovascular disturbances: advocacy for a watchful attitude in this never-ending story

INTRODUCTION

Thanks to the emergence of new therapeutics, prognosis and outcome of breast cancer patients (any subtype) have improved significantly. This raises the issue of the interactions and side effects related to the use of multiple drugs. Thus, to decide on a treatment, the optimal benefit risk-ratio should be carefully watched as toxicities such as cardiac ones effect on long-term survival. Indeed, nowadays in France, cardiovascular diseases rank first as causes of death in women.

AREAS COVERED

This non-exhaustive review aims to report the currently available data on cardiac side effects caused by the use of emerging drugs in breast cancer, in localized or metastatic diseases alike. We will focus on HER2-inhibitors, cyclin-dependent-kinase 4/6 and PARP inhibitors, chemotherapy and immunotherapy, before discussing the means of prevention.

EXPERT OPINION

Although this issue has largely been studied, the recent emergence of new drugs emphasizes the necessity for oncologists to adapt their practice to a multidisciplinary model that includes cardio-oncology.

Treatment of Triple Negative Cell Lines with Olaparib to Block DNA Repair

BACKGROUND

The most aggressive breast cancer is the triple negative histological type and the gold standard for its treatment is platinum salts, such as carboplatin. Due to high recurrence, there is a need to test new drugs, such as PARP inhibitors (PARPi) that induce lethality in cells with DNA damage. Olaparib is a PARPi, already used in some tumors, but not tested in canine species. Thus, the aim of this study was demonstrating the efficacy of olaparib in inhibiting DNA repair and controlling disease progression by decreasing the migration capacity of mammary tumor cells.

METHODS

The cell lines, CF41.Mg and MDA-MB-468, were cultured and was performed the MTT to define the best dose of carboplatin. Next, the cells were treated with 10 µM carboplatin, olaparib and with combination of both for 24 hours. PARP-1 protein and gene expression was evaluated by immunofluorescence, western blotting and qRT-PCR, respectively. The analysis of cell migration was performed in transwell chambers.

RESULTS

For CF41.Mg and MDA-MB-468 cell lines, there was decrease in PARP-1 protein and gene expression after treatment with carboplatin, olaparib and both in combination compared to the group without treatment (control) (p<0.05). Moreover, in both lines, reduction in invasion rate was observed after treatment with carboplatin, olaparib and when combined, compared to the control group (p<0.05).

CONCLUSION

Our data suggests that carboplatin and olaparib were able to block DNA repair and control the cancer invasion, especially when used in combination. The results with olaparib in the canine line are unpublished. The olaparib should be a possible agent against human breast cancer and canine mammary tumors.

Phase II trial of veliparib and temozolomide in metastatic breast cancer patients with and without BRCA1/2 mutations

PURPOSE

We evaluated the efficacy and safety of poly-(adenosine diphosphate-ribose) polymerase (PARP) 1 and 2 inhibitor veliparib and temozolomide in metastatic breast cancer patients with and without germline BRCA1/2 mutations.

METHODS

In this single-arm phase II trial, patients with metastatic breast cancer received veliparib 30 to 40 mg twice daily on days 1 to 7 with concurrent temozolomide 150 mg/m² on days 1 to 5 of a 28-day cycle. The primary cohort was unselected for BRCA mutation status, and an expansion cohort enrolled only BRCA1/2 carriers. The primary endpoint was objective response rate (ORR) in each cohort. Secondary endpoints included progression-free survival (PFS), clinical benefit rate (CBR), and evaluation of safety and tolerability.

RESULTS

In the primary cohort of 41 unselected patients, which included 9 BRCA mutation carriers, the ORR was 10% and clinical benefit rate at 4 months (CBR) was 27%. In the expansion cohort of 21 BRCA1/2 carriers, the ORR was 14% and CBR was 43%. Among all 30 BRCA1/2 carriers, the ORR was 23% versus 0% among non-carriers. In the subset of BRCA1/2 carriers, the ORR was 32% among platinum-naïve patients versus 9% among platinum-exposed patients. The median PFS was 3.3 months among BRCA1/2 carriers compared to 1.8 months among non-carriers (HR: 0.48, p = 0.006). A longer median PFS of 6.2 months was observed among BRCA1/2 carriers who had no prior platinum therapy. The most common grade 3 and 4 toxicities were thrombocytopenia (32%) and neutropenia (21%) that generally improved with dose modifications.

CONCLUSION

Veliparib and temozolomide demonstrated clinical activity in platinum-naïve BRCA-associated metastatic breast cancer with manageable toxicity at doses of veliparib well below the single-agent active dose. Although the study did not meet its primary endpoint in unselected nor BRCA-associated breast cancer, this regimen was further evaluated in the BROCADE 2 study.

TRIAL REGISTRATION

NCT01009788 (ClinicalTrials.gov), November 9, 2009.

Relevance of Platinum-free Interval and BRCA Reversion Mutations for Veliparib Monotherapy after Progression on Carboplatin/Paclitaxel for gBRCA Advanced Breast Cancer (BROCADE3 Crossover)

PURPOSE

Safety, efficacy, and exploratory biomarker analyses were evaluated in patients with advanced HER2-negative germline breast cancer susceptibility gene (gBRCA)-associated breast cancer enrolled in the BROCADE3 trial who received crossover veliparib monotherapy after disease progression on placebo plus carboplatin/paclitaxel.

PATIENTS AND METHODS

Eligible patients (N = 513) were randomized 2:1 to veliparib plus carboplatin/paclitaxel or placebo plus carboplatin/paclitaxel; patients had variable platinum-free intervals (PFI) at progression. In the placebo arm, patients were eligible to receive crossover veliparib monotherapy (300-400 mg twice daily continuous). Antitumor activity and adverse events were assessed during crossover veliparib treatment. BRCA reversion mutations at crossover were analyzed retrospectively using next-generation sequencing on plasma circulating tumor DNA (ctDNA).

RESULTS

Seventy-five patients in the placebo plus carboplatin/paclitaxel arm received ≥1 dose of crossover veliparib postprogression (mean treatment duration: 154 days). Eight of 50 (16%) patients with measurable disease had a RECIST v1.1 response. Activity was greater in patients with PFI ≥180 days compared with <180 days [responses in 23.1% (3/13) vs. 13.5% (5/37) of patients]. BRCA reversion mutations that restored protein function were detected in ctDNA from 4 of 28 patients tested, and the mean duration of crossover veliparib monotherapy was <1 month in these 4 patients versus 7.49 months in patients lacking reversion mutations. The most frequent adverse events were nausea (61%), vomiting (29%), and fatigue (24%).

CONCLUSIONS

Crossover veliparib monotherapy demonstrated limited antitumor activity in patients who experienced disease progression on placebo plus carboplatin/paclitaxel. PFI appeared to affect veliparib activity. BRCA reversion mutations may promote cross-resistance and limit veliparib activity following progression on platinum.

A common goal to CARE: Cancer Advocates, Researchers, and Clinicians Explore current treatments and clinical trials for breast cancer brain metastases

Breast cancer is the most commonly diagnosed cancer in women worldwide. Approximately one-tenth of all patients with advanced breast cancer develop brain metastases resulting in an overall survival rate of fewer than 2 years. The challenges lie in developing new approaches to treat, monitor, and prevent breast cancer brain metastasis (BCBM). This review will provide an overview of BCBM from the integrated perspective of clinicians, researchers, and patient advocates. We will summarize the current management of BCBM, including diagnosis, treatment, and monitoring. We will highlight ongoing translational research for BCBM, including clinical trials and improved detection methods that can become the mainstay for BCBM treatment if they demonstrate efficacy. We will discuss preclinical BCBM research that focuses on the intrinsic properties of breast cancer cells and the influence of the brain microenvironment. Finally, we will spotlight emerging studies and future research needs to improve survival outcomes and preserve the quality of life for patients with BCBM.

Efficacy and safety of first-line veliparib and carboplatin-paclitaxel in patients with HER2- advanced germline BRCA+ breast cancer: Subgroup analysis of a randomised clinical trial

BACKGROUND

Addition of veliparib to carboplatin-paclitaxel, with continuation of veliparib monotherapy if carboplatin-paclitaxel was discontinued, improved progression-free survival (PFS) in patients with germline BRCA-associated locally advanced/metastatic HER2- breast cancer and ≤2 lines of previous cytotoxic therapy for metastatic disease in BROCADE3. A pre-planned subgroup analysis evaluated efficacy and safety in patients without previous cytotoxic therapy for metastatic disease.

METHODS

Patients were randomised 2:1 to receive veliparib (120 mg orally BID) or placebo on days -2 to 5. Carboplatin (AUC 6) was administered on day 1, and paclitaxel (80 mg/m2) on days 1, 8 and 15 (21-day cycles). Patients discontinuing carboplatin-paclitaxel for reasons besides progression could continue veliparib/placebo monotherapy (300 mg BID, increasing to 400 mg BID if tolerated) until progression. The primary end-point was PFS assessed by investigator.

RESULTS

Of 509 patients in the intention-to-treat population (98.6% female; mean age 47, standard deviation 11), 413 (81%) had no previous cytotoxic therapy for metastatic disease (274, veliparib; 139, placebo). In the first-line subgroup, median PFS was 16.6 months (95% confidence interval [CI] 13.4-18.7) versus 13.1 months (95% CI 11.4-14.5) for the veliparib versus control groups (hazard ratio 0.70, 95% CI 0.54-0.89, P = .004). More patients were alive and progression-free at 2 years (36% versus 23.2%) and 3 years (27.9% versus 13.3%) in the veliparib versus control group. Adverse events unrelated to progression leading to study drug discontinuation occurred in 25 (9.1%) and 8 (5.8%) patients.

CONCLUSIONS

Veliparib with carboplatin-paclitaxel led to durable disease control among first-line patients, suggesting a benefit of this treatment approach in early lines.

CLINICAL TRIAL REGISTRATION

NCT02163694.

Efficacy and safety of PARP inhibitors in patients with BRCA-mutated advanced breast cancer: A meta-analysis and systematic review

Objective

This meta-analysis aimed to investigate the efficacy and safety of poly (adenosine diphosphate-ribose) polymerase (PARP) inhibitors in BRCA-mutated advanced breast cancer patients comprehensively.

Methods

We conducted a systematic literature research through PubMed, the Cochrane Central Register of Controlled Trials (CENTRAL), Embase, China National Knowledge Infrastructure (CNKI), wanfang, China Biology Medicine disc (CBMdisc), and ClinicalTrials.gov from inception to January 2021. Randomized controlled trials (RCTs) with available data comparing PARP inhibitors versus control therapy in BRCA-mutated advanced breast cancer were eligible for analysis. Statistical analyses were performed with Review Manager (RevMan) version 5.4 and R version 4.0.3.

Results

1706 studies were retrieved in total, and 4 RCTs with 1540 patients were eligible for meta-analysis finally. The results showed that progression-free survival (PFS) and overall survival (OS) were significantly improved in germline BRCA-mutated breast cancer patients with PARP inhibitors (HR 0.64, 95% CI [0.56–0.74]; HR 0.86, 95% CI [0.74–0.99], respectively) with no significant heterogeneity across studies (I² = 22%, χ² p = 0.28; I² = 0%, χ² p = 0.70, respectively). There was no significant difference in the overall adverse events (AEs), grade≥3 AEs and AEs leading to treatment discontinuation between PARP inhibitor arms and control arms (RR 1.01, 95% CI [0.99–1.02]; RR 0.95, 95% CI [0.83–1.09]; RR 1.17, 95% CI [0.87–1.57], respectively). Based on the available data, PARP inhibitors provided comparable or better results than control arms in improving the quality of life in BRCA-mutated advanced breast cancer patients.

Conclusions

PARP inhibitors prolonged PFS and OS among patients with BRCA-mutated advanced breast cancer with tolerable safety and improved quality of life.

•

PARP inhibitors showed encouraging efficacy in BRCA-mutated advanced breast cancer.

•

The safety of PARP inhibitors was tolerable.

•

We included both PARP inhibitor monotherapy and combination therapy studies.

Breast Cancer Treatments: Updates and New Challenges

Breast cancer (BC) is the most frequent cancer diagnosed in women worldwide. This heterogeneous disease can be classified into four molecular subtypes (luminal A, luminal B, HER2 and triple-negative breast cancer (TNBC)) according to the expression of the estrogen receptor (ER) and the progesterone receptor (PR), and the overexpression of the human epidermal growth factor receptor 2 (HER2). Current BC treatments target these receptors (endocrine and anti-HER2 therapies) as a personalized treatment. Along with chemotherapy and radiotherapy, these therapies can have severe adverse effects and patients can develop resistance to these agents. Moreover, TNBC do not have standardized treatments. Hence, a deeper understanding of the development of new treatments that are more specific and effective in treating each BC subgroup is key. New approaches have recently emerged such as immunotherapy, conjugated antibodies, and targeting other metabolic pathways. This review summarizes current BC treatments and explores the new treatment strategies from a personalized therapy perspective and the resulting challenges.

Moving beyond PARP Inhibition: Current State and Future Perspectives in Breast Cancer

Breast cancer is the most frequent and lethal tumor in women and finding the best therapeutic strategy for each patient is an important challenge. PARP inhibitors (PARPis) are the first, clinically approved drugs designed to exploit synthetic lethality in tumors harboring BRCA1/2 mutations. Recent evidence indicates that PARPis have the potential to be used both in monotherapy and combination strategies in breast cancer treatment. In this review, we show the mechanism of action of PARPis and discuss the latest clinical applications in different breast cancer treatment settings, including the use as neoadjuvant and adjuvant approaches. Furthermore, as a class, PARPis show many similarities but also certain critical differences which can have essential clinical implications. Finally, we report the current knowledge about the resistance mechanisms to PARPis. A systematic PubMed search, using the entry terms “PARP inhibitors” and “breast cancer”, was performed to identify all published clinical trials (Phase I-II-III) and ongoing trials (ClinicalTrials.gov), that have been reported and discussed in this review.

BRCA Mutational Status is a Promising Predictive Biomarker for Platinum- based Chemotherapy in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) can be distinguished from other breast malignancies by the lack of expression of estrogen receptors (ER), progesterone receptors (PR) as well as human epidermal growth factor receptor 2 (HER2). TNBC is associated with adverse clinical outcomes and high risk of metastasis. Currently, several clinical and translational reports are focusing on developing targeted therapies for this aggressive cancer. In addition to approved targeted drugs such as poly(ADP-ribose) polymerase inhibitors (PARPi) and immune-checkpoint inhibitors, platinum-based chemotherapy is still a cornerstone therapeutic option in TNBC. However, despite the observed improved outcomes with platinum- based chemotherapy in TNBC, there is still a large proportion of patients who do not respond to this treatment, hence, the need for predictive biomarkers to stratify TNBC patients and therefore, avoiding unwanted toxicities of these agents. With the emergence of genetic testing, several recent studies suggested mutations in breast cancer susceptibility gene (BRCA) in TNBC patients as important predictors of outcomes. These mutations alter the homologous recombination repair (HRR) mechanisms leading to genomic instability. Consequently, sensitivity to platinum-based treatments in this subpopulation of TNBC patients may be explained by cell death enhanced by deoxyribonucleic acid (DNA) damage induced by these potent anticancer drugs. Through this paper, we review several recent studies on this topic to better understand the mechanisms and discuss the potential of BRCA mutational status as a predictive biomarker of platinum-based chemotherapy in TNBC.

Indirect treatment comparison of olaparib and talazoparib in germline BRCA-mutated HER2-negative metastatic breast cancer

Aim: Two poly(ADP-ribose) polymerase (PARP) inhibitors olaparib and talazoparib are approved for patients with germline BRCA-mutated (gBRCAm) HER2-negative metastatic breast cancer. Methods: A Bayesian fixed-effects indirect treatment comparison (ITC) analysis was performed to simulate the comparative efficacy (primary outcome of progression-free survival [PFS]) and safety of PARP inhibitor monotherapy. Results: ITC of data from the OlympiAD (olaparib) and EMBRACA (talazoparib) studies suggested no significant difference in efficacy (PFS) between olaparib and talazoparib. However, there were differences in specific adverse events; patients receiving olaparib had a higher rate of nausea and vomiting, while those receiving talazoparib had a higher rate of alopecia and anemia. Discussion: These data support the benefit of the PARP inhibitor class in gBRCAm HER2-negative metastatic breast cancer.

Breast cancer brain metastasis: insight into molecular mechanisms and therapeutic strategies

Breast cancer is one of the most prevalent malignancies in women worldwide. Early-stage breast cancer is considered a curable disease; however, once distant metastasis occurs, the 5-year overall survival rate of patients becomes significantly reduced. There are four distinct metastatic patterns in breast cancer: bone, lung, liver and brain. Among these, breast cancer brain metastasis (BCBM) is the leading cause of death; it is highly associated with impaired quality of life and poor prognosis due to the limited permeability of the blood-brain barrier and consequent lack of effective treatments. Although the sequence of events in BCBM is universally accepted, the underlying mechanisms have not yet been fully elucidated. In this review, we outline progress surrounding the molecular mechanisms involved in BCBM as well as experimental methods and research models to better understand the process. We further discuss the challenges in the management of brain metastases, as well as providing an overview of current therapies and highlighting innovative research towards developing novel efficacious targeted therapies.

Systematic review of combinations of targeted or immunotherapy in advanced solid tumors

With rapid advances in our understanding of cancer, there is an expanding number of potential novel combination therapies, including novel-novel combinations. Identifying which combinations are appropriate and in which subpopulations are among the most difficult questions in medical research. We conducted a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-guided systematic review of trials of novel-novel combination therapies involving immunotherapies or molecular targeted therapies in advanced solid tumors. A MEDLINE search was conducted using a modified Cochrane Highly Sensitive Search Strategy for published clinical trials between July 1, 2017, and June 30, 2020, in the top-ranked medical and oncology journals. Trials were evaluated according to a criterion adapted from previously published Food and Drug Administration guidance and other key considerations in designing trials of combinations. This included the presence of a strong biological rationale, the use of a new established or emerging predictive biomarker prospectively incorporated into the clinical trial design, appropriate comparator arms of monotherapy or supportive external data sources and a primary endpoint demonstrating a clinically meaningful benefit. Of 32 identified trials, there were 11 (34%) trials of the novel-novel combination of anti-programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) and anti-cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) therapy, and 10 (31%) trials of anti-PD-1/PD-L1 and anti-vascular endothelial growth factor (VEGF) combination therapy. 20 (62.5%) trials were phase II trials, while 12 (37.5%) were phase III trials. Most (72%) trials lacked significant preclinical evidence supporting the development of the combination in the given indication. A majority of trials (69%) were conducted in biomarker unselected populations or used pre-existing biomarkers within the given indication for patient selection. Most studies (66%) were considered to have appropriate comparator arms or had supportive external data sources such as prior studies of monotherapy. All studies were evaluated as selecting a clinically meaningful primary endpoint. In conclusion, designing trials to evaluate novel-novel combination therapies presents numerous challenges to demonstrate efficacy in a comprehensive manner. A greater understanding of biological rationale for combinations and incorporating predictive biomarkers may improve effective evaluation of combination therapies. Innovative statistical methods and increasing use of external data to support combination approaches are potential strategies that may improve the efficiency of trial design. Designing trials to evaluate novel-novel combination therapies presents numerous challenges to demonstrate efficacy in a comprehensive manner. A greater understanding of biological rationale for combinations and incorporating predictive biomarkers may improve effective evaluation of combination therapies. Innovative statistical methods and increasing use of external data to support combination approaches are potential strategies that may improve the efficiency of trial design.

Pathogenesis and Potential Therapeutic Targets for Triple-Negative Breast Cancer

Triple negative breast cancer (TNBC) is a heterogeneous tumor characterized by early recurrence, high invasion, and poor prognosis. Currently, its treatment includes chemotherapy, which shows a suboptimal efficacy. However, with the increasing studies on TNBC subtypes and tumor molecular biology, great progress has been made in targeted therapy for TNBC. The new developments in the treatment of breast cancer include targeted therapy, which has the advantages of accurate positioning, high efficiency, and low toxicity, as compared to surgery, radiotherapy, and chemotherapy. Given its importance as cancer treatment, we review the latest research on the subtypes of TNBC and relevant targeted therapies.

Perspectives on PARP inhibitors as pharmacotherapeutic strategies for breast cancer

Introduction Approximately 10% of all breast cancer cases occur in individuals who have germline pathogenic variants of the BRCA 1, BRCA 2, and other genes associated with impaired DNA damage repair that is associated with an increased risk of breast, ovarian, and other cancers. Inhibitors of poly-ADP ribose polymerase (PARP) induce synthetic lethality in cancer cells harboring such pathogenic variants.Area covered In this review, the authors review the mechanisms of action, antitumor activity, and adverse events associated with PARP inhibitors for the treatment of advanced breast cancer. The authors then summarize the area and provide their expert perspectives on the area.Expert opinion Two PARP inhibitors are approved in metastatic breast cancer, including olaparib and talozaparib. Both agents were approved based on phase III trials demonstrating that they were associated with improved progression-free survival compared with treatment of physician's choice in patients receiving second-third line therapy for locally advanced, inoperable, or metastatic breast cancer in patients with germline pathogenic BRCA 1 or BRCA2 variants.

Evaluation of efficacy and safety of PARP inhibitors in breast cancer: A systematic review and meta-analysis

BACKGROUND

Many breast cancer clinical trials with PARPi have been completed or are currently carried out, either by monotherapy or combined with chemotherapy. We aim to assess the efficacy and safety of PARPi in breast cancer patients as compared to chemotherapy.

METHODS

A comprehensive literature search of PubMed, EMBASE, CENTRAL, conference meetings and clinical trial registry was performed. The primary outcomes were progression-free survival (PFS), overall survival (OS), overall response rate (ORR). The secondary outcome was safety profile. The comparative effects were measured using hazard ratio (HR) or relative risk (RR) with 95% confidence interval. Subgroup analyses were conducted based on types of intervention and baseline characteristics of patients.

RESULTS

Six RCTs (n = 1953) were included. Two RCTs were recognized as high risk. PARPi was associated with an improved PFS (HR, 0.65; 95% CI, 0.56-0.74), OS (HR, 0.86; 95% CI, 0.73-1.01), and a higher ORR (RR, 1.38; 95% CI, 1.05-1.82). PARPi, however, significantly increased risk of grade 3-4 thrombocytopenia (RR, 1.63; 95% CI, 1.06-2.52). Monotherapy was observed with lower risk of disease progression and higher ORR rate than combination therapy, 0.56 to 0.65 and 2.21 to 1.05, respectively. For patients without prior platinum treatment, PARPi significantly improved PFS (HR, 0.64; 95% CI, 0.52-0.79).

CONCLUSIONS

PARPi was observed with a significantly improved efficacy in aspects of PFS and ORR, but also higher risk of grade 3-4 thrombocytopenia as compared to chemotherapy. PARPi was a better choice for patients who had not received previous platinum treatment.

A randomized phase II trial of veliparib, radiotherapy and temozolomide in patients with unmethylated MGMT glioblastoma: the VERTU study

Background

Temozolomide offers minimal benefit in patients with glioblastoma with unmethylated O⁶-methylguanine-DNA methyltransferase (MGMT) promoter status, hence, the need for novel therapies. This study evaluated whether veliparib, a brain-penetrant poly(ADP-ribose) polymerase (PARP) inhibitor, acts synergistically with radiation and temozolomide.

Methods

VERTU was a multicenter 2:1 randomized phase II trial in patients with newly diagnosed glioblastoma and MGMT-unmethylated promotor status. The experimental arm consisted of veliparib and radiotherapy, followed by adjuvant veliparib and temozolomide. The standard arm consisted of concurrent temozolomide and radiotherapy, followed by adjuvant temozolomide. The primary objective was to extend the progression-free survival rate at six months (PFS-6m) in the experimental arm.

Results

A total of 125 participants were enrolled, with 84 in the experimental arm and 41 in the standard arm. The median age was 61 years, 70% were male, 59% had Eastern Cooperative Oncology Group (ECOG) performance status of 0, and 87% underwent macroscopic resection. PFS-6m was 46% (95% confidence interval [CI]: 36%-57%) in the experimental arm and 31% (95% CI: 18%-46%) in the standard arm. Median overall survival was 12.7 months (95% CI: 11.4-14.5 months) in the experimental arm and 12.8 months (95% CI: 9.5-15.8 months) in the standard arm. The most common grade 3-4 adverse events were thrombocytopenia and neutropenia, with no new safety signals.

Conclusion

The veliparib-containing regimen was feasible and well tolerated. However, there was insufficient evidence of clinical benefit in this population. Further information from correlative translational work and other trials of PARP inhibitors in glioblastoma are still awaited.

Breast-Gynaecological & Immuno-Oncology International Cancer Conference (BGICC) Consensus and Recommendations for the Management of Triple-Negative Breast Cancer

Background: The management of patients with triple-negative breast cancer (TNBC) is challenging with several controversies and unmet needs. During the 12th Breast-Gynaecological & Immuno-oncology International Cancer Conference (BGICC) Egypt, 2020, a panel of 35 breast cancer experts from 13 countries voted on consensus guidelines for the clinical management of TNBC. The consensus was subsequently updated based on the most recent data evolved lately. Methods: A consensus conference approach adapted from the American Society of Clinical Oncology (ASCO) was utilized. The panellists voted anonymously on each question, and a consensus was achieved when ≥75% of voters selected an answer. The final consensus was later circulated to the panellists for critical revision of important intellectual content. Results and conclusion: These recommendations represent the available clinical evidence and expert opinion when evidence is scarce. The percentage of the consensus votes, levels of evidence and grades of recommendation are presented for each statement. The consensus covered all the aspects of TNBC management starting from defining TNBC to the management of metastatic disease and highlighted the rapidly evolving landscape in this field. Consensus was reached in 70% of the statements (35/50). In addition, areas of warranted research were identified to guide future prospective clinical trials.

A phase I/II study of veliparib (ABT-888) with radiation and temozolomide in newly diagnosed diffuse pontine glioma: a Pediatric Brain Tumor Consortium study

BACKGROUND

A Pediatric Brain Tumor Consortium (PBTC) phase I/II trial of veliparib and radiation followed by veliparib and temozolomide (TMZ) was conducted in children with newly diagnosed diffuse intrinsic pontine glioma (DIPG). The objectives were to: (i) estimate the recommended phase II dose (RP2D) of veliparib with concurrent radiation; (ii) evaluate the pharmacokinetic parameters of veliparib during radiation; (iii) evaluate feasibility of intrapatient TMZ dose escalation; (iv) describe toxicities of protocol therapy; and (v) estimate the overall survival distribution compared with historical series.

METHODS

Veliparib was given Monday through Friday b.i.d. during radiation followed by a 4-week rest. Patients then received veliparib at 25 mg/m2 b.i.d. and TMZ 135 mg/m2 daily for 5 days every 28 days. Intrapatient dose escalation of TMZ was investigated for patients experiencing minimal toxicity.

RESULTS

Sixty-six patients (65 eligible) were enrolled. The RP2D of veliparib was 65 mg/m2 b.i.d. with radiation. Dose-limiting toxicities during radiation with veliparib therapy included: grade 2 intratumoral hemorrhage (n = 1), grade 3 maculopapular rash (n = 2), and grade 3 nervous system disorder (generalized neurologic deterioration) (n = 1). Intrapatient TMZ dose escalation during maintenance was not tolerated. Following a planned interim analysis, it was concluded that this treatment did not show a survival benefit compared with PBTC historical controls, and accrual was stopped for futility. The 1- and 2-year overall survival rates were 37.2% (SE 7%) and 5.3% (SE 3%), respectively.

CONCLUSION

Addition of veliparib to radiation followed by TMZ and veliparib was tolerated but did not improve survival for patients with newly diagnosed DIPG.

TRIAL REGISTRATION

NCT01514201.

PARP (Poly ADP-Ribose Polymerase) inhibitors for locally advanced or metastatic breast cancer

BACKGROUND

Locally advanced and metastatic breast cancer remains a challenge to treat. With emerging study results, it is important to interpret the available clinical data and apply the evidence offering the most effective treatment to the right patient. Poly(ADP Ribose) Polymerase (PARP) inhibitors are a new class of drug and their role in the treatment of locally advanced and metastatic breast cancer is being established.

OBJECTIVES

To determine the efficacy, safety profile, and potential harms of Poly(ADP-Ribose) Polymerase (PARP) inhibitors in the treatment of patients with locally advanced or metastatic breast cancer. The primary outcome of interest was overall survival; secondary outcomes included progression-free survival, tumour response rate, quality of life, and adverse events.

SEARCH METHODS

On 8 June 2020, we searched the Cochrane Breast Cancer Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE via OvidSP, Embase via OvidSP, World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) search portal and ClinicalTrials.gov. We also searched proceedings from the major oncology conferences as well as scanned reference lists from eligible publications and contacted corresponding authors of trials for further information, where needed.

SELECTION CRITERIA

We included randomised controlled trials on participants with locally advanced or metastatic breast cancer comparing 1) chemotherapy in combination with PARP inhibitors, compared to the same chemotherapy without PARP inhibitors or 2) treatment with PARP inhibitors, compared to treatment with other chemotherapy. We included studies that reported on our primary outcome of overall survival and secondary outcomes including progression-free survival, tumour response rate, quality of life, and adverse events.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures defined by Cochrane. Summary statistics for the endpoints used hazard ratios (HR) with 95% confidence intervals (CI) for overall survival and progression-free survival, and odds ratios (OR) for response rate (RR) and toxicity.

MAIN RESULTS

We identified 49 articles for qualitative synthesis, describing five randomised controlled trials that were included in the quantitative synthesis (meta-analysis). A sixth trial was assessed as eligible but had ended prematurely and no data were available for inclusion in our meta-analysis. Risk of bias was predominately low to unclear across all studies except in regards to performance bias (3/5 high risk) and detection bias for the outcomes of quality of life (2/2 high risk) and reporting of adverse events (3/5 high risk). High-certainty evidence shows there may be a small advantage in overall survival (HR 0.87, 95% CI 0.76 to 1.00; 4 studies; 1435 patients). High-certainty evidence shows that PARP inhibitors offer an improvement in PFS in locally advanced/metastatic HER2-negative, BRCA germline mutated breast cancer patients (HR 0.63, 95% CI 0.56 to 0.71; 5 studies; 1474 patients). There was no statistical heterogeneity for these outcomes. Subgroup analyses for PFS outcomes based on trial level data were performed for triple-negative breast cancer, hormone-positive and/or HER2-positive breast cancer, BRCA1 and BRCA2 germline mutations, and patients who had received prior chemotherapy for advanced breast cancer or not. The subgroup analyses showed a persistent PFS benefit regardless of the subgroup chosen. Pooled analysis shows PARP inhibitors likely result in a moderate improvement in tumour response rate compared to other treatment arms (66.9% vs 48.9%; RR 1.39, 95% CI 1.24 to 1.54; 5 studies; 1185 participants; moderate-certainty evidence). The most common adverse events reported across all five studies included neutropenia, anaemia and fatigue. Grade 3 or higher adverse events probably occur no less frequently in patients receiving PARP inhibitors (59.4% for PARP arm versus 64.5% for non-PARP arm, RR 0.98, 95% CI 0.91 to 1.04; 5 studies; 1443 participants; moderate-certainty evidence). Only two studies reported quality of life outcomes so this was not amenable to meta-analysis. However, both studies that did assess quality of life showed PARP inhibitors were superior compared to physician's choice of chemotherapy in terms of participant-reported outcomes.

AUTHORS' CONCLUSIONS

In people with locally advanced or metastatic HER2-negative, BRCA germline mutated breast cancer, PARP inhibitors offer an improvement in progression-free survival, and likely improve overall survival and tumour response rates. This systematic review provides evidence supporting the use of PARP inhibitors as part of the therapeutic strategy for breast cancer patients in this subgroup. The toxicity profile for PARP inhibitors is probably no worse than chemotherapy but more information is required regarding quality of life outcomes, highlighting the importance of collecting such data in future studies. Future studies should also be powered to detect clinically important differences in overall survival and could focus on the role of PARP inhibitors in other relevant breast cancer populations, including HER2-positive, BRCA-negative/homologous recombination repair-deficient and Programmed Death-Ligand 1 (PDL1) positive.

Poly (ADP-ribose) polymerase inhibitors in solid tumours: Systematic review and meta-analysis

BACKGROUND

Poly (ADP-ribose) polymerase-inhibitors (PARPis) showed antitumour activity in BRCA1/2-mutated cancers, with more heterogeneous outcomes in tumours harbouring mutations that impair other genes involved in the DNA homologous recombination repair (HRR) or wild-type (wt).

METHODS

We conducted a systematic review and meta-analysis to better assess the role of PARPis in the treatment of metastatic solid tumours, with and without BRCA1/2 mutations. The primary end-point was progression-free survival (PFS). The secondary end-points were overall response rate (ORR) and overall survival (OS). A random-effects model was applied.

RESULTS

Twenty-nine studies (8,839 patients) were included. PFS was significantly improved (hazard ratio [HR]: 0.59, 95% confidence interval [CI]: 0.51-0.68, p < 0.001), without being affected by BRCA mutational status (p = 0.65). Significant subgroup differences were observed with regard to the tumour site (p = 0.001), line of therapy (p = 0.002), control arm (p < 0.001), type of PARPi (p < 0.001) and trials' phase (p = 0.006). PARPis were associated with ORR (relative risk: 1.35, 95% CI: 1.16-1.56, p < 0.001), with significant subgroup differences observed with regard to treatment line (p = 0.03), control arm (p = 0.04) and PARPis (p < 0.001) and independent of mutational status (p = 0.44), tumour site (p = 0.86) and trials' phase (p = 0.09). OS was significantly improved by PARPis (HR: 0.86, 95% CI: 0.80-0.92, p < 0.001), regardless of mutational status (p = 0.57), tumour site (p = 0.82), treatment line (p = 0.22), control arm (p = 0.21), PARPis (p = 0.30) and trials' phase (p = 0.26). Finally, an exploratory subgroup analysis showed a significant PFS improvement (HR: 0.51, 95% CI: 0.43-0.60, p < 0.001) with PARPis in BRCA-wt/HRR-deficient tumours.

CONCLUSION

Our results confirm the efficacy of already approved PARPi-based treatments in BRCA1/2-mutant solid tumours, support their role also in BRCA-independent HRR-deficient tumours and suggest a potentially broader efficacy in some wt tumours, perhaps with appropriate therapeutic partners. Prospective studies are warranted.

Temozolomide: An Updated Overview of Resistance Mechanisms, Nanotechnology Advances and Clinical Applications

Temozolomide (TMZ), an oral alkylating prodrug which delivers a methyl group to purine bases of DNA (O6-guanine; N7-guanine and N3-adenine), is frequently used together with radiotherapy as part of the first-line treatment of high-grade gliomas. The main advantages are its high oral bioavailability (almost 100% although the concentration found in the cerebrospinal fluid was approximately 20% of the plasma concentration of TMZ), its lipophilic properties, and small size that confer the ability to cross the blood-brain barrier. Furthermore, this agent has demonstrated activity not only in brain tumors but also in a variety of solid tumors. However, conventional therapy using surgery, radiation, and TMZ in glioblastoma results in a median patient survival of 14.6 months. Treatment failure has been associated with tumor drug resistance. This phenomenon has been linked to the expression of O6-methylguanine-DNA methyltransferase, but the mismatch repair system and the presence of cancer stem-like cells in tumors have also been related to TMZ resistance. The understanding of these mechanisms is essential for the development of new therapeutic strategies in the clinical use of TMZ, including the use of nanomaterial delivery systems and the association with other chemotherapy agents. The aim of this review is to summarize the resistance mechanisms of TMZ and the current advances to improve its clinical use.

Sequential delivery of dual drugs with nanostructured lipid carriers for improving synergistic tumor treatment effect

To improve synergistic anticancer efficacy and minimize the adverse effects of chemotherapeutic drugs, temozolomide (TMZ) and curcumin (CUR) co-loaded nanostructured lipid carriers (NLCs) were prepared by microemulsion in this study. And the physicochemical properties, drug release behavior, intracellular uptake efficiency, in vitro and in vivo anticancer effects of TMZ/CUR-NLCs were evaluated. TMZ/CUR-NLCs showed enhanced inhibitory effects on glioma cells compared to single drug loaded NLCs, which may be owing to that the quickly released CUR can sensitize the cancer cells to TMZ. The inhibitory mechanism is a combination of S phase cell cycle arrest associated with induced apoptosis. Notably, TMZ/CUR-NLCs can accumulate at brain and tumor sites effectively and perform a significant synergistic anticancer effect in vivo. More importantly, the toxic effects of TMZ/CUR-NLCs on major organs and normal cells at the same therapeutic dosage were not observed. In conclusion, NLCs are promising nanocarriers for delivering dual chemotherapeutic drugs sequentially, showing potentials in the synergistic treatment of tumors while reducing adverse effects both in vitro and in vivo.

PARP inhibitor treatment of advanced breast cancer beyond the BRCA-mutated type: a meta-analysis

Background: We conducted this meta-analysis to compare the efficacy and safety of PARP inhibitors with or without chemotherapy versus chemotherapy alone for advanced breast cancer. Methods: A meta-analysis and trial sequential analysis were performed using RevMan 5.2 analysis software. Results: Six eligible randomized clinical trials involving 2080 patients were included. Regimens containing PARP inhibitors were significantly associated with higher objective response rate, longer progression-free survival and overall survival. The PARP inhibitor regimen group had a significantly higher rate of grade ≥3 thrombocytopenia than the chemotherapy-only group. Conclusion: Regimens containing PARP inhibitors are effective and safe for BRCA-mutated advanced breast cancer patients. The efficacy appears to be only marginal in patients with BRCA status unselected.

Overview of recent advances in metastatic triple negative breast cancer

Metastatic triple negative breast cancer (TNBC) has an aggressive phenotype with a predilection for visceral organs and brain. Best responses to chemotherapy are predominately in the first line. Recent studies have demonstrated improved progression free survival with the combination of atezolizumab/pembrolizumab and chemotherapy in programmed death-ligand 1 positive metastatic TNBC. However, a recent trial in a similar population showed no benefit for atezoli-zumab and paclitaxel which led to a Food and Drug Administration alert. Two phase III trials (OLYMPIAD and BROCADE3) demonstrated a benefit in progression free survival (PFS) but not overall survival in patients with BRCA-associated metastatic TNBC treated with Olaparib or Talazoparib respectively. For those treated with Talazoparib, the time to deterioration in health related-quality of life was also longer compared to chemotherapy. The BROCADE3 trial demonstrated that the combination of a platinum and veliparib increased PFS in first-line metastatic TNBC but at the cost of increased toxicity. There are no head-to-head comparisons of a poly (adenosine diphosphate-ribose) polymerase inhibitors (PARPi) and platinums. There are unanswered questions regarding the role of PARPi maintenance after platinum therapy as is standard of care in BRCA-associated ovarian cancer. Other areas of therapeutic interest include targeting aberrations in the phosphoinositide 3-kinase pathway, protein kinase B, mammalian target of rapamycin or utilising antibody drug conjugates. This review focusses on recent and emerging therapeutic options in metastatic TNBC. We searched PubMed, clinicaltrials.gov and recent international meetings from American Society of Clinical Oncology, San Antonio Breast Cancer Conference and the European Society of Medical Oncology.

Emerging Therapeutic Drugs in Metastatic Triple-Negative Breast Cancer

Metastatic triple-negative breast cancer (TNBC) is a heterogeneous disease with a poor prognosis and currently with few treatment options. Treatment of these patients is highly based on systemic chemotherapy. Some targeted drugs were recently approved for these patients: two poly(ADP-ribose) polymerase inhibitors in patients with germline BRCA1/2 mutations (olaparib and talazoparib), immune checkpoint inhibitors in association with chemotherapy if programmed death-ligand 1 positive (atezolizumab plus nabpaclitaxel and pembrolizumab plus chemotherapy [nabpaclitaxel, paclitaxel, and carboplatin plus gemcitabine]), and an antibody-drug conjugate sacituzumab-govitecan in heavily pretreated patients (at least 2 previous lines for the metastatic setting). Combinations using these and other targeted treatment options are under investigation in early and late clinical trials, and we will probably have some practice-changing results in the new future. Other targeted drugs explored in phase II and phase III clinical trials are PI3K/AKT pathway inhibitors and androgen receptor antagonists in patients with alterations in these signaling pathways. The definition of molecular subtypes has been essential for the development of these treatment strategies. Soon, the treatment of metastatic TNBC could be based on personalized medicine using molecular testing for targeted drugs instead of only systemic chemotherapy. The authors present a review of emerging treatment options in metastatic TNBC, focusing on targeted drugs, including the recent data published in 2020.

PARP Inhibitors in Cancer Diagnosis and Therapy

Targeting of PARP enzymes has emerged as an effective therapeutic strategy to selectively target cancer cells with deficiencies in homologous recombination signaling. Currently used to treat BRCA-mutated cancers, PARP inhibitors (PARPi) have demonstrated improved outcome in various cancer types as single agents. Ongoing efforts have seen the exploitation of PARPi combination therapies, boosting patient responses as a result of drug synergisms. Despite great successes using PARPi therapy, selecting those patients who will benefit from single agent or combination therapy remains one of the major challenges. Numerous reports have demonstrated that the presence of a BRCA mutation does not always result in synthetic lethality with PARPi therapy in treatment-naïve tumors. Cancer cells can also develop resistance to PARPi therapy. Hence, combination therapy may significantly affect the treatment outcomes. In this review, we discuss the development and utilization of PARPi in different cancer types from preclinical models to clinical trials, provide a current overview of the potential uses of PARP imaging agents in cancer therapy, and discuss the use of radiolabeled PARPi as radionuclide therapies.

Incidence of myelodysplastic syndrome and acute myeloid leukemia in patients receiving poly-ADP ribose polymerase inhibitors for the treatment of solid tumors: A meta-analysis of randomized trials

BACKGROUND

Clinical trials demonstrated that PARPi (poly [adenosine diphosphate-ribose]-ADP polymerase inhibitor) therapy is effective in solid tumors. However, long term effects such as therapy-related myelodysplastic syndrome or acute myeloid leukemia (MDS/AML) are poorly described. We sought to quantify whether PARPi therapy is associated with the development of MDS/AML.

METHODS

Medline, Embase, and Cochrane databases were searched (inception to January 6, 2020) and phase 2 and 3 clinical trials that randomized patients with solid tumors to a PARPi or control therapy were included. The PRISMA guidelines were used to extract data independently by multiple authors. We extracted person-time and number of cases of MDS/AML in the PARPi and control arms of each study and pooled results with a random-effects Poisson regression model. The pooled incidence rate ratio (IRR) for MDS/AML among patients randomized to PARPi therapy was compared to those randomized to a control.

RESULTS

We identified 14 studies that included 5739 patients. Accounting for intra-study clustering, the risk of MDS/AML was similar in patients who were randomly assigned to receive PARPi compared to controls (IRR 1.32, 95% confidence interval [CI] 0.78-2.26). In the front-line setting, PARPi therapy was associated with developing MDS/AML (IRR 5.43, 95% CI 1.51-19.60). Among patients treated for recurrence, however, the risk of MDS/AML appeared to be similar among patients randomized to PARPi or control treatment. Among studies that included only patients with a BRCA mutation, the risk of MDS/AML was similar in both treatment groups (IRR 0.83, 95% CI 0.45-1.53), but PARPi therapy was associated with MDS/AML in studies with an unrestricted population (IRR 2.43, 95% CI 1.17-5.06).

CONCLUSION

The pooled overall effect was not statistically significant. However, treatment with PARPi was associated with a statistically significant increase in the incidence of MDS/AML among patients receiving front-line cancer therapy and those with limited prior exposure to chemotherapy.

PARP inhibitors in breast and ovarian cancer with BRCA mutations: a meta-analysis of survival

Objective: To evaluate the efficacy of poly ADP ribose polymerase (PARP) inhibitors (PARPis) in breast and ovarian cancer with BRCA (BReast CAncer susceptibility gene) mutation (BRCAm).

Methods: We conducted a meta-analysis of randomized controlled, phase II or III trials by searching of electronic databases from inception to September 1, 2020. The efficacy of PARPis measured by hazard ratios (HRs) and 95% confidence intervals (95% CIs) for progression free survival (PFS) and overall survival (OS) of patients.

Results: By addition of PARPis to conventional therapy, breast or ovarian cancer patients carrying BRCAm significantly benefited PFS (breast cancer: HR 0.64, 95% CI=0.55-0.75, P<0.001; ovarian cancer: HR 0.33, 95% CI=0.27-0.42, P<0.001), but OS of patients did not increase significantly in these two cancer types (breast cancer: HR 0.87, 95% CI=0.76-1.01, P=0.065; ovarian cancer: HR 0.78, 95% CI=0.61-1.01, P=0.058). For ovarian cancer patients carrying BRCAm, the use of therapy with PARPis yielded longer PFS at the stage of newly diagnosed than the stage of recurrence (22.5 months vs 9.6 months).

Conclusion: PARPis were beneficial to all with BRCAm, but they were "most" beneficial to the ovarian cancer subset when administered early after diagnosis, rather than after recurrence.

The role of DNA damage response in chemo- and radio-resistance of cancer cells: Can DDR inhibitors sole the problem?

Up to now, many improvements have been made in providing more therapeutic strategies for cancer patients. The lack of susceptibility to common therapies like chemo- and radio-therapy is one of the reasons why we need more methods in the field of cancer therapy. DNA damage response (DDR) is a set of mechanisms which identifies DNA lesions and triggers the repair process for restoring DNA after causing an arrest in the cell cycle. The ability of DDR in maintaining the genome stability and integrity can be favorable to cancerous cells which are exposed to radiation therapy or are treated with chemotherapeutic agents. When DDR mechanisms are error-free in cancer cells, they can escape the expected cellular death and display resistance to treatment. In this regard, targeting different components of DDR can help to increase the susceptibility of advanced tumors to chemo- and radio-therapy.

DNA damage response inhibitors: An avenue for TNBC treatment

The DNA damage response (DDR) is critical for the maintenance of genomic stability by sensing DNA damage, regulating cell cycle and initiating DNA repair. Drugs targeting DDR pathways have been increasingly exploited in treating various tumors. Triple negative breast cancer (TNBC) is a highly heterogeneous and aggressive tumor with constitutive activation of oncogenes, inducing replication stress and DNA damage, which require the DDR for survival. In addition, emerging studies have demonstrated that TNBC harbors aberrant genetic alterations in DDR pathways, such as a high frequency of p53 dysfunction and BRCA1/2 mutations. DDR alterations force TNBC to rely on the existing DDR pathways for survival, and make TNBC particularly sensitive to specific DDR inhibitors, such as high sensitivity of TNBC with BRCA1/2 mutations to PARP inhibitors. This review first and comprehensively covers the current status of the development of DDR inhibitors and discusses the mechanism of targeting the DDR in TNBC. Preclinical and clinical studies on inhibitors of the ATR-CHK1-WEE1 pathway and PARP inhibitors, the most studied inhibitors, and some other DDR inhibitors as monotherapy or combination therapy in TNBC are summarized. We also highlight the possible predictive biomarkers for these DDR inhibitors and their potential combination strategies with chemotherapy, radiotherapy or other targeted agents to optimize the efficacy of DDR inhibitors in TNBC treatment. In conclusion, this review discussed the recent considerations related to the use of DDR inhibitors for TNBC and provides a perspective to address future directions and potential therapeutic strategies for patients with TNBC.

A phase I trial adding poly(ADP-ribose) polymerase inhibitor veliparib to induction carboplatin-paclitaxel in patients with head and neck squamous cell carcinoma: Alliance A091101

OBJECTIVES

We report the results of this phase I study to evaluate the maximum tolerated dose (MTD) and safety of veliparib, a poly(ADP-ribose) polymerase (PARP) inhibitor, combined with carboplatin and paclitaxel induction chemotherapy (IC) for locoregionally advanced head and neck squamous cell carcinoma (HNSCC).

MATERIALS AND METHODS

In a 3 + 3 cohort design, patients with stage IVA-B human papillomavirus-negative HNSCC received 2 cycles of carboplatin (AUC 6, day 1), paclitaxel (100 mg/m², days 1, 8, 15) and veliparib (days 1-7) every 21 days followed by standard curative-intent chemoradiotherapy. Primary endpoint: MTD and recommended phase II dose (RP2D) as determined by the first IC cycle.

RESULTS

Twenty patients enrolled. Two withdrew before treatment; 18 patients were analyzed. Median age was 63 years. Primary disease sites included hypopharynx (n = 5), larynx (n = 5), oral cavity (n = 4), oropharynx (n = 3), and nasal cavity (n = 1). Through all of IC, the most common grade 3 + adverse events (AEs) were neutropenia (33%), thrombocytopenia (33%), anemia (11%), and white blood cell decrease (11%). One patient experienced a hematologic DLT at 350 mg BID. The RP2D for veliparib combined with carboplatin/paclitaxel is 350 mg BID. With 40.9 month median follow-up across dose levels for all patients, the 24-month overall and progression free survival was 77.8% (95% CI 60.8-99.6%) and 66.7% (95% CI 48.1-92.4%), respectively. Medians have not been reached.

CONCLUSION

Addition of veliparib to carboplatin and paclitaxel IC was well tolerated in patients with advanced HNSCC. Hematologic toxicities were the most common AEs.

PARP Inhibitors in Triple-Negative Breast Cancer Including Those With BRCA Mutations

ABSTRACT

Poly(ADP-ribose) polymerase (PARP) is involved in single-strand DNA break base excision repair. PARP inhibition causes synthetic lethality in breast cancers associated with germline BRCA1 and BRCA2 mutations and is routinely used in clinical practice for metastatic breast cancer. Breast cancers with homologous recombination deficiency or BRCAness, most commonly triple-negative breast cancers, may also benefit. Currently, PARP inhibitor use for triple-negative breast cancer with wild-type BRCA does not have definitive efficacy; however, this is an area of active research. Further clinical and translational data may identify additional patient populations that will benefit from PARP inhibitor therapy.

BRCA testing and outcomes in women with breast cancer

MAIN PURPOSE

Germline BRCA mutations (BRCAm) strongly influence the risk of developing breast cancer. This study aimed to understand the role of BRCAm testing in affected individuals and to assess its impact on the outcome of BRCAm carriers compared to non-carriers (BRCAwt) with breast cancer.

RESEARCH QUESTION

The research question is "Does standard of care testing for BRCAm improve survival outcomes of breast cancer patients?"

METHODS

In a single institution observational cohort study, demographic and clinical characteristics were compared between breast cancer patients with and without BRCAm. Frequency of BRCA testing was assessed. Survival outcomes were assessed by initial treatment setting stratified by BRCA status.

RESULTS

Of 5712 identified women with breast cancer, 14.6% (n = 835) were tested for a BRCA mutation and had a documented result. The total number and proportion of women tested for a BRCAm increased between 2000 and 2014, resulting in an increased number of BRCAm carriers identified. However, the proportion of women who underwent testing and had a BRCAm decreased during the study period from 27.5% in 2000-2004 to 13.3% in 2010-2014. Disease-free survival was similar in the adjuvant and neoadjuvant treatment settings between BRCAm and BRCAwt patients. Progression-free survival on first line treatment and overall survival for patients with metastatic disease was also similar between BRCAm and BRCAwt patients.

CONCLUSIONS

The proportion of women tested and the number of BRCAm identified increased during the study period despite a decreasing proportion of positive results among women tested.

Myelodysplastic syndrome and acute myeloid leukaemia in patients treated with PARP inhibitors: a safety meta-analysis of randomised controlled trials and a retrospective study of the WHO pharmacovigilance database

BACKGROUND

Poly(ADP-ribose) polymerase (PARP) inhibitors have shown efficacy and acceptable safety in a range of neoplasms, particularly in ovarian cancers. However, some concerns have emerged regarding rare and delayed adverse events including cases of myelodysplastic syndrome and acute myeloid leukaemia, for which data are scarce. The aim of this study was to estimate the risk of myelodysplastic syndrome and acute myeloid leukaemia related to PARP inhibitors, via a systematic review and safety meta-analysis, and to describe clinical features of PARP inhibitor-related myelodysplastic syndrome and acute myeloid leukaemia cases reported in WHO's pharmacovigilance database (VigiBase).

METHODS

We systematically reviewed randomised controlled trials (RCTs) comparing PARP inhibitor therapy versus control treatments (placebo and non-placebo) in adults (age ≥18 years) treated for cancer in MEDLINE, the Cochrane Central Register of Controlled Trials, and the ClinicalTrials.gov registry with ongoing surveillance up to May 31, 2020. The date range for included studies was not restricted. By a stepwise method to capture all available adverse events, we first extracted data on myelodysplastic syndrome and acute myeloid leukaemia cases from ClinicalTrials.gov. If cases were not available, we extracted them from published manuscripts, or subsequently contacted corresponding authors or sponsors to provide data. RCTs without available data from ClinicalTrials.gov, publications, or corresponding authors or sponsors were excluded. The primary outcome was the summary risk of myelodysplastic syndrome and acute myeloid leukaemia related to PARP inhibition versus placebo treatment in RCTs. We used a fixed-effects meta-analysis to obtain Peto odds ratios (ORs) with 95% CIs. In a separate observational, retrospective, cross-sectional pharmacovigilance study of VigiBase, cases of myelodysplastic syndrome and acute myeloid leukaemia related to PARP inhibitor therapy were extracted on May 3, 2020, and clinical features summarised with a focus on median duration of PARP inhibitor exposure, median latency period between first drug exposure and diagnosis, and proportion of cases resulting in death. Our systematic review and safety meta-analysis were registered with PROSPERO, CRD42020175050. Our retrospective pharmacovigilance study was registered on ClinicalTrials.gov, NCT04326023.

FINDINGS

For our safety meta-analysis, initial searches identified 1617 citations, and 31 RCTs were systematically reviewed for eligibility. 28 RCTs with available adverse events were analysed (18 placebo and ten non-placebo RCTs), with 5693 patients in PARP inhibitor groups and 3406 patients in control groups. Based on the 18 placebo RCTs (n=7307 patients), PARP inhibitors significantly increased the risk of myelodysplastic syndrome and acute myeloid leukaemia compared with placebo treatment (Peto OR 2·63 [95% CI 1·13-6·14], p=0·026) with no between-study heterogeneity (I²=0%, χ² p=0·91). The incidence of myelodysplastic syndrome and acute myeloid leukaemia across PARP inhibitor groups was 0·73% (95% CI 0·50-1·07; I²=0%, χ² p=0·87; 21 events out of 4533 patients) and across placebo groups was 0·47% (0·26-0·85; I²=0%, χ² p=1·00; three events out of 2774 patients). All 28 RCTs were rated as having unclear risk of bias. In VigiBase, 178 cases of myelodysplastic syndrome (n=99) and acute myeloid leukaemia (n=79) related to PARP inhibitor therapy were extracted. In cases with available data, median treatment duration was 9·8 months (IQR 3·6-17·4; n=96) and median latency period since first exposure to a PARP inhibitor was 17·8 months (8·4-29·2; n=58). Of 104 cases that reported outcomes, 47 (45%) resulted in death.

INTERPRETATION

PARP inhibitors increased the risk of myelodysplastic syndrome and acute myeloid leukaemia versus placebo treatment. These delayed and often lethal adverse events should be studied further to improve clinical understanding, particularly in the front-line maintenance setting.

FUNDING

None.

Molecular Features and Clinical Management of Hereditary Gynecological Cancers

Hereditary gynecological cancers are caused by several inherited genes. Tumors that arise in the female reproductive system, such as ovaries and the uterus, overlap with hereditary cancers. Several hereditary cancer-related genes are important because they might lead to therapeutic targets. Treatment of hereditary cancers should be updated in line with the advent of various new methods of evaluation. Next-generation sequencing has led to rapid, economical genetic analyses that have prompted a concomitant and significant paradigm shift with respect to hereditary cancers. Molecular tumor profiling is an epochal method for determining therapeutic targets. Clinical treatment strategies are now being designed based on biomarkers based on tumor profiling. Furthermore, the National Comprehensive Cancer Network (NCCN) guidelines significantly changed the genetic testing process in 2020 to initially consider multi-gene panel (MGP) evaluation. Here, we reviewed the molecular features and clinical management of hereditary gynecological malignancies, such as hereditary breast and ovarian cancer (HBOC), and Lynch, Li–Fraumeni, Cowden, and Peutz–Jeghers syndromes. We also reviewed cancer-susceptible genes revealed by MGP tests.

Gastrointestinal events with PARP inhibitors in cancer patients: A meta-analysis of phase II/III randomized controlled trials

WHAT IS KNOWN AND OBJECTIVE

PARP inhibitors are currently one of the most promising PARP targeted drugs for patients with certain types of cancer. Gastrointestinal (GI) events are common adverse events for all PARP inhibitors. We conducted this meta-analysis of randomized controlled trials (RCTs) to fully investigate the incidence and the relative risk of GI events in cancer patients receiving PARP inhibitors.

STUDY DESIGN

Randomized controlled trials in cancer patients treated with PARP inhibitors were retrieved, and the systematic evaluation was conducted. Embase and PubMed/Medline were searched for articles published till July 2020.

RESULTS

Twenty-nine RCTs and 9529 patients were included. The present meta-analysis suggests that the use of PARP inhibitors significantly increases the risk of developing all-grade nausea (RR, 1.46; 95% CI, 1.29-1.66; p < .00001), vomiting (RR, 1.39; 95% CI, 1.17-1.64; p = .0001), diarrhoea (RR, 1.14; 95% CI, 1.06-1.23; p = .0003) and decreased appetite (RR, 1.24; 95% CI, 1.14-1.36; p < .00001), but not for constipation. And the use of these agents significantly increased the risk of high-grade nausea (RR, 1.99; 95% CI, 1.44-2.74; p < .0001), vomiting (RR, 1.54; 95% CI, 1.11-2.14; p = .01) and decreased appetite (RR, 2.03; 95% CI, 1.22-3.40; p = .007), except for diarrhoea and constipation. Nausea was the most common GI event for these agents. Patients receiving veliparib were associated with a relatively lower risk of all-grade nausea and vomiting. Patients with ovarian cancer tend to have a higher risk of all-grade nausea and vomiting than those with non-ovarian cancer. The risk of all-grade nausea and vomiting tended to be higher when PARP inhibitors treatment was longer.

WHAT IS NEW AND CONCLUSION

PARP inhibitors were associated with a significant increased risk of GI events. Clinicians should be aware of these risks and perform regular monitoring.

Platinum-containing regimens for triple-negative metastatic breast cancer

BACKGROUND

In a previous Cochrane Review, we found that for women with metastatic breast cancer unselected for triple-negative disease, there is little or no survival benefit and excess toxicity from platinum-based regimens. In subgroup analyses, however, we found preliminary low-quality evidence of a survival benefit from platinum-based regimens for women with metastatic triple-negative breast cancer (mTNBC). This review updates the evidence from the mTNBC subgroup analyses in the previous Cochrane Review.

OBJECTIVES

To assess the effects of platinum-containing chemotherapy regimens with regimens not containing platinum in the management of women with mTNBC.

SEARCH METHODS

We obtained relevant studies published prior to 2015 and their extracted results from the mTNBC subgroup analysis in the previous Cochrane Review. We searched the Cochrane Breast Cancer Group's Specialised Register, CENTRAL, MEDLINE, Embase, the World Health Organization's International Clinical Trials Registry Platform and ClinicalTrials.gov between 2015 and 27 September 2019. We identified further potentially relevant studies from previous trial reports, systematic reviews, and meta-analyses.

SELECTION CRITERIA

Randomised trials comparing platinum-containing chemotherapy regimens with regimens not containing platinum in women with mTNBC. Individual trials could compare one or more platinum-based regimens to one or more non-platinum regimens; hence there could be more 'treatment-comparisons' (i.e. platinum regimen versus non-platinum regimen comparison) than trials. Trial participants may have been purposely selected for mTNBC or inadvertently selected as a subgroup.

DATA COLLECTION AND ANALYSIS

At least two independent reviewers assessed studies for eligibility and quality, and extracted all relevant data from each study. We derived hazard ratios (HRs) for time-to-event outcomes, where possible, and used fixed-effect models for meta-analyses. We analysed objective tumour response rates (OTRRs) and toxicities as binary (dichotomous) outcomes with risk ratios (RRs) used as measures of effects. We extracted quality of life data, if available. We used GRADE to rate the quality of evidence for time-to-event and tumour response outcomes.

MAIN RESULTS

This review includes 13 treatment-comparisons involving 1349 women from 10 studies. Twelve of the 13 treatment-comparisons were included in one or more meta-analyses. Of the 13 treatment-comparisons, six and eight had published or provided time-to-event data on overall survival (OS) or progression-free survival/time to progression (PFS/TTP), respectively, that could be included in meta-analyses. Ten treatment-comparisons published or provided OTRR data that could be included in meta-analyses. Eight of the 13 treatment-comparisons were from studies that selected participants on the basis of mTNBC status, while the other five treatment-comparisons were from studies that reported mTNBC results as part of subgroup analyses. Analysis of six treatment-comparisons indicated that platinum-containing regimens may have provided a small survival benefit to mTNBC patients (HR 0.85, 95% CI 0.73 to 1.00; 958 women; moderate-quality evidence) with no evidence of heterogeneity (P = 0.41; I2 = 1%). Data from eight treatment-comparisons showed that platinum regimens may improve PFS/TTP (HR 0.77, 95% CI 0.68 to 0.88; 1077 women; very low-quality evidence). There was marked evidence of heterogeneity (P < 0.0001; I2 = 80%). There was also low-quality evidence of better tumour response for platinum recipients (RR 1.40, 95% CI 1.22 to 1.59; 1205 women) with some evidence of heterogeneity (P = 0.01; I2 = 58%). The observed heterogeneity for the PFS/TTP and OTRR outcomes may reflect between-study differences and general difficulties in assessing tumour response, as well as the varying potencies of the comparators. Compared with women receiving non-platinum regimens: rates of grade 3 and 4 nausea/vomiting were higher for platinum recipients (RR 4.77, 95% CI 1.93 to 11.81; 655 women; low-quality evidence) and rates of grade 3 and 4 anaemia were higher for platinum recipients (RR 3.80, 95% CI 2.25 to 6.42; 843 women; low-quality evidence). In general, however, relatively few intervention-comparisons could be included in meta-analyses for adverse events. None of the studies reported quality of life.

AUTHORS' CONCLUSIONS

For women with mTNBC, there was moderate-quality evidence of a small survival benefit from platinum-based regimens compared to non-platinum regimens. This finding is consistent with findings of a PFS/TTP benefit and improved tumour response from platinum-based regimens. These potential benefits, however, should be weighed against previously identified excess toxicities from platinum-based regimens, particularly regimens containing cisplatin. Further randomised trials of platinum-based regimens among women with mTNBC are required.

Practical classification of triple-negative breast cancer: intratumoral heterogeneity, mechanisms of drug resistance, and novel therapies

Triple-negative breast cancer (TNBC) is not a unique disease, encompassing multiple entities with marked histopathological, transcriptomic and genomic heterogeneity. Despite several efforts, transcriptomic and genomic classifications have remained merely theoretic and most of the patients are being treated with chemotherapy. Driver alterations in potentially targetable genes, including PIK3CA and AKT, have been identified across TNBC subtypes, prompting the implementation of biomarker-driven therapeutic approaches. However, biomarker-based treatments as well as immune checkpoint inhibitor-based immunotherapy have provided contrasting and limited results so far. Accordingly, a better characterization of the genomic and immune contexture underpinning TNBC, as well as the translation of the lessons learnt in the metastatic disease to the early setting would improve patients' outcomes. The application of multi-omics technologies, biocomputational algorithms, assays for minimal residual disease monitoring and novel clinical trial designs are strongly warranted to pave the way toward personalized anticancer treatment for patients with TNBC.

Clinical characteristics and prognostic implications of BRCA-associated tumors in males: a pan-tumor survey

BACKGROUND

The BRCA mutation (BRCAm) in males has been reported to confer a higher risk for the development of various tumors. However, little is known about its clinicopathologic features and prognostic implications.

DESIGN

We conducted a retrospective pan-tumor survey on 346 cases of BRCA-associated tumors in males. Comparative analyses were conducted among male and female patients with BRCAm (n = 349), as well as in male patients without BRCAm (n = 4577).

RESULTS

Similar incidences of BRCAm (6.0 vs. 6.6%) and age at diagnosis of tumor (median, 65 vs. 60 years) were observed in male and female patients. Carcinomas of the lung, bladder, stomach, and cutaneous melanoma were the frequent tumors demonstrating BRCAm in males, of which the majority were stage II or III diseases with a higher frequency of BRCA2 mutations. Compared to that in the non-BRCAm group, cutaneous melanoma (16.3 vs. 5.0%), lung cancer (19.4 vs. 11.8%), bladder cancer (15.6 vs. 5.6%), and stomach cancer (11.9 vs. 5.5%) accounted for a higher proportion in the BRCAm group. Advanced disease and more mutation counts (median, 322 vs. 63 mutations) were also found in the BRCAm group. A total of 127 BRCA1 and 311 BRCA2 mutations were identified, of which 21.8 and 28.6% were deleterious, respectively. Frequent deleterious variants were identified in carcinomas of the breast (100.0%), colorectum (62.2%), prostate (43.3%), and stomach (42.9%). BRCA1 fusions with NF1, FAM134C, BECN1, or LSM12 and recurrent BRCA2 mutations at P606L/S, E832K/G, and T3033Lfs*29 were detected. Frameshift mutations in BRCA2 at N1784 (N1784Kfs*3, N1784Tfs*3) were frequently observed in both male and female patients. Compared with those in females, BRCA mutations in males were associated with decreased overall survival (OS) and progression-free survival (PFS). Male patients with deleterious BRCAm displayed increased OS compared with non-BRCAm carriers. The subgroup analysis demonstrated that BRCAm was associated with increased OS in gastric and bladder cancers, decreased PFS in prostate, esophageal, and head and neck cancers, and decreased OS in glioma/glioblastoma in males.

CONCLUSION

These findings provide an overview of the distinct characteristics and clinical outcomes of male patients with BRCA-associated tumors, suggesting the importance of further genetic BRCA testing in males.

Veliparib with carboplatin and paclitaxel in BRCA-mutated advanced breast cancer (BROCADE3): a randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

BRCA1 or BRCA2-mutated breast cancers are sensitive to poly(ADP-ribose) polymerase (PARP) inhibitors and platinum agents owing to deficiency in homologous recombination repair of DNA damage. In this trial, we compared veliparib versus placebo in combination with carboplatin and paclitaxel, and continued as monotherapy if carboplatin and paclitaxel were discontinued before progression, in patients with HER2-negative advanced breast cancer and a germline BRCA1 or BRCA2 mutation.

METHODS

BROCADE3 was a randomised, double-blind, placebo-controlled, phase 3 trial done at 147 hospitals in 36 countries. Eligible patients (aged ≥18 years) had deleterious germline BRCA1 or BRCA2 mutation-associated, histologically or cytologically confirmed advanced HER2-negative breast cancer, an Eastern Cooperative Oncology Group performance status of 0-2, and had received up to two previous lines of chemotherapy for metastatic disease. Patients were randomly assigned (2:1) by interactive response technology by means of permuted blocks within strata (block size of 3 or 6) to carboplatin (area under the concentration curve 6 mg/mL per min intravenously) on day 1 and paclitaxel (80 mg/m2 intravenously) on days 1, 8, and 15 of 21-day cycles combined with either veliparib (120 mg orally twice daily, on days -2 to 5) or matching placebo. If patients discontinued carboplatin and paclitaxel before progression, they could continue veliparib or placebo at an intensified dose (300 mg twice daily continuously, escalating to 400 mg twice daily if tolerated) until disease progression. Patients in the control group could receive open-label veliparib monotherapy after disease progression. Randomisation was stratified by previous platinum use, history of CNS metastases, and oestrogen and progesterone receptor status. The primary endpoint was investigator-assessed progression-free survival per Response Evaluation Criteria in Solid Tumors version 1.1. Efficacy analyses were done by intention to treat, which included all randomly assigned patients with a centrally confirmed BRCA mutation, and safety analyses included all patients who received at least one dose of velilparib or placebo. This study is ongoing and is registered with ClinicalTrials.gov, NCT02163694.

FINDINGS

Between July 30, 2014, and Jan 17, 2018, 2202 patients were screened, of whom 513 eligible patients were enrolled and randomly assigned. In the intention-to-treat population (n=509), 337 patients were assigned to receive veliparib plus carboplatin-paclitaxel (veliparib group) and 172 were assigned to receive placebo plus carboplatin-paclitaxel (control group). Median follow-up at data cutoff (April 5, 2019) was 35·7 months (IQR 24·9-43·6) in the veliparib group and 35·5 months (23·1-45·9) in the control group. Median progression-free survival was 14·5 months (95% CI 12·5-17·7) in the veliparib group versus 12·6 months (10·6-14·4) in the control group (hazard ratio 0·71 [95% CI 0·57-0·88], p=0·0016). The most common grade 3 or worse adverse events were neutropenia (272 [81%] of 336 patients in the veliparib group vs 143 [84%] of 171 patients in the control group), anaemia (142 [42%] vs 68 [40%]), and thrombocytopenia (134 [40%] vs 48 [28%]). Serious adverse events occurred in 115 (34%) patients in the veliparib group versus 49 (29%) patients in the control group. There were no study drug-related deaths.

INTERPRETATION

The addition of veliparib to a highly active platinum doublet, with continuation as monotherapy if the doublet were discontinued, resulted in significant and durable improvement in progression-free survival in patients with germline BRCA mutation-associated advanced breast cancer. These data indicate the utility of combining platinum and PARP inhibitors in this patient population.

FUNDING

AbbVie.