Marie Robert

Olaparib for the treatment of breast cancer

ABSTRACT Introduction: Basal-like breast cancer is characterized by being triple negative and aggressive. Defects in DNA repair is a promising therapeutic target as BRCA alterations are found in 11 to 42% of these tumors, with a frequency varying according to family history and ethnicity. The oral PARP inhibitors exploit this deficiency through a synthetic lethality and are considered as promising anticancer therapies, especially in patients harboring BRCA1 or BRCA 2 mutations. Areas covered: Olaparib is one of the most widely investigated PARP inhibitors. Here, the preclinical data, completed clinical trials and ongoing investigations are discussed. Expert opinion: PARP inhibitors show promising results in breast cancer. However, several issues are raised including the identification of biomarkers to predict treatment response and strategies to counteract emerging resistance. Moreover, the results from ongoing phase III trials of olaparib in breast cancer are still awaited.

Emerging PARP inhibitors for treating breast cancer

ABSTRACT Introduction: Some breast cancers harbor defects in DNA repair pathways, including BRCA1 and BRCA2 mutations, leading to a genomic instability. Compromised DNA-damage repair response is found in 11 to 42% of triple negative breast cancers, with a frequency varying according to family history and ethnicity. The oral PARP inhibitors are a promising strategy in breast cancer exploiting Homologous Deficient Recombination deficiency (HRD) by a synthetic lethal approach. Several PARP inhibitors have currently reached early phase trials with studies on going in the adjuvant, neoadjuvant and metastatic setting. Area covered: Here, we review completed and ongoing trials with PARP inhibitors as well as their mechanisms of activity and acquired resistance. Expert opinion: PARP inhibitors show promising results in breast cancer. However, several issues are raised including the identification of biomarkers to predict treatment response and strategies to counteract emerging resistance.

An Update on the Clinical Use of CDK4/6 Inhibitors in Breast Cancer

Deregulated cell division, resulting in aberrant cell proliferation, is one of the key hallmarks of cancer. Cyclin-dependent kinases (CDKs) play a central role in cell cycle progression in cancer, and the clinical development of the CDK4/6 inhibitors palbociclib, ribociclib, and abemaciclib has changed clinical practice in the setting of endocrine-receptor positive breast cancer. Results of pivotal phase II and III trials investigating these CDK4/6 inhibitors in patients with endocrine receptor-positive, advanced breast cancer have demonstrated a significant improvement in progression-free survival, with a safe toxicity profile. No validated biomarkers of sensitivity or resistance exist at the moment. Future development of CDK4/6 inhibitors in breast cancer should focus on the identification of predictive biomarkers, the development of drug combinations to overcome resistance, and the application of CDK4/6 inhibitors to other breast cancer subtypes.

Retrospective Analysis of CA19-9 Decrease in Patients with Metastatic Pancreatic Carcinoma Treated with FOLFIRINOX or Gemcitabine in a Randomized Phase III Study (ACCORD11/PRODIGE4)

Objectives: Carbohydrate antigen 19-9 (CA19-9) is a sensitive and specific serum marker in pancreatic cancer. Our retrospective analysis aims to evaluate CA19-9 decrease in patients with metastatic pancreatic cancer treated in ACCORD11/PRODIGE4 (FOLFIRINOX vs. gemcitabine). Methods: A total of 342 patients were treated. CA19-9 was measured at 8 weeks (±2) in 160 patients from a total of 282 with abnormal CA19-9 values at baseline (gemcitabine arm, n = 75; FOLFIRINOX arm, n = 85). In the present study, 8-week CA19-9 decrease or greater CA19-9 decrease according to the 20 and 90% thresholds were analyzed. Progression-free survival (PFS) and overall survival (OS) were estimated in each subgroup. Results: In the FOLFIRINOX arm, patients with an 8-week CA19-9 decrease or greater CA19-9 decrease ≥20% showed improved median OS, PFS, and objective response rate. In the overall study population, median OS and PFS were significantly improved in patients with an 8-week CA19-9 decrease ≥20% (vs. <20%). The 8-week CA19-9 decrease was predictive of PFS (interaction test significant according to treatment arm; p = 0.006). Conclusion: An 8-week CA19-9 decrease ≥20% is a prognostic factor for OS and PFS. The 8-week CA19-9 decrease (20% threshold) is predictive of PFS. It could help to evaluate the efficacy of FOLFIRINOX and gemcitabine regimens.

Efficacy of buparlisib in treating breast cancer

ABSTRACT Introduction: Breast cancer is the most frequent cancer in women. Despite a decline in breast cancer mortality, prognosis of advanced breast cancer remains poor. In a desperate need to improve breast cancer outcomes, newer agents that target molecular pathways are being tested. Deregulation of the phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) is frequently found in breast cancer. This can lead to resistance of endocrine therapy and anti-HER2 therapies. Targeting this pathway may restore sensitivity to these compounds. Buparlisib (BKM-120) is an orally active pan-PI3K inhibitor evaluated in different tumor types. Areas covered: Buparlisib is one of the most investigated PI3K inhibitors. Preclinical and clinical studies of buparlisib in breast cancer are analyzed and discussed. This article reviews the status of buparlisib, completed and ongoing trials, and its safety. Expert opinion: PI3K inhibitors show promising results in breast cancer. However, we raise a number of issues including the identification of biomarkers to predict treatment response and strategies to counteract resistance. Moreover, its toxicity profile could limit its extensive use.