Poly (ADP-Ribose) Polymerase Inhibitors: Talazoparib in Ovarian Cancer and Beyond.

Genetic complexity and DNA damage repair defects are common in different cancer types and can induce tumor-specific vulnerabilities. Poly(ADP-ribose) polymerase (PARP) inhibitors exploit defects in the DNA repair pathway through synthetic lethality and have emerged as promising anticancer therapies, especially in tumors harboring deleterious germline or somatic breast cancer susceptibility gene (BRCA) mutations. However, the utility of PARP inhibitors could be expanded beyond germline BRCA1/2 mutated cancers by causing DNA damage with cytotoxic agents in the presence of a DNA repair inhibitor. US Food and Drug Administration (FDA)-approved PARP inhibitors include olaparib, rucaparib, and niraparib, while veliparib is in the late stage of clinical development. Talazoparib inhibits PARP catalytic activity, trapping PARP1/2 on damaged DNA, and it has been approved by the US FDA for the treatment of metastatic germline BRCA1/2 mutated breast cancers in October 2018. The talazoparib side effect profile more closely resembles traditional chemotherapeutics rather than other clinically approved PARP inhibitors. In this review, we discuss the scientific evidence that has emerged from both experimental and clinical studies in the development of talazoparib. Future directions will include optimizing combination therapy with chemotherapy, immunotherapies and targeted therapies, and in developing and validating biomarkers for patient selection and stratification, particularly in malignancies with 'BRCAness'

HER2-enriched subtype and novel molecular subgroups drive aromatase inhibitor resistance and an increased risk of relapse in early ER+/HER2+ breast cancer

BACKGROUND: Oestrogen receptor positive/ human epidermal growth factor receptor positive (ER+/HER2+) breast cancers (BCs) are less responsive to endocrine therapy than ER+/HER2- tumours. Mechanisms underpinning the differential behaviour of ER+HER2+ tumours are poorly characterised. Our aim was to identify biomarkers of response to 2 weeks’ presurgical AI treatment in ER+/HER2+ BCs. METHODS: All available ER+/HER2+ BC baseline tumours (n=342) in the POETIC trial were gene expression profiled using BC360™ (NanoString) covering intrinsic subtypes and 46 key biological signatures. Early response to AI was assessed by changes in Ki67 expression and residual Ki67 at 2 weeks (Ki672wk). Time-To-Recurrence (TTR) was estimated using Kaplan-Meier methods and Cox models adjusted for standard clinicopathological variables. New molecular subgroups (MS) were identified using consensus clustering. FINDINGS: HER2-enriched (HER2-E) subtype BCs (44.7% of the total) showed poorer Ki67 response and higher Ki672wk (p<0.0001) than non-HER2-E BCs. High expression of ERBB2 expression, homologous recombination deficiency (HRD) and TP53 mutational score were associated with poor response and immune-related signatures with High Ki672wk. Five new MS that were associated with differential response to AI were identified. HER2-E had significantly poorer TTR compared to Luminal BCs (HR 2.55, 95% CI 1.14–5.69; p=0.0222). The new MS were independent predictors of TTR, adding significant value beyond intrinsic subtypes. INTERPRETATION: Our results show HER2-E as a standardised biomarker associated with poor response to AI and worse outcome in ER+/HER2+. HRD, TP53 mutational score and immune-tumour tolerance are predictive biomarkers for poor response to AI. Lastly, novel MS identify additional non-HER2-E tumours not responding to AI with an increased risk of relapse

Poly (ADP-Ribose) Polymerase Inhibitors: Talazoparib in Ovarian Cancer and Beyond.

Genetic complexity and DNA damage repair defects are common in different cancer types and can induce tumor-specific vulnerabilities. Poly(ADP-ribose) polymerase (PARP) inhibitors exploit defects in the DNA repair pathway through synthetic lethality and have emerged as promising anticancer therapies, especially in tumors harboring deleterious germline or somatic breast cancer susceptibility gene (BRCA) mutations. However, the utility of PARP inhibitors could be expanded beyond germline BRCA1/2 mutated cancers by causing DNA damage with cytotoxic agents in the presence of a DNA repair inhibitor. US Food and Drug Administration (FDA)-approved PARP inhibitors include olaparib, rucaparib, and niraparib, while veliparib is in the late stage of clinical development. Talazoparib inhibits PARP catalytic activity, trapping PARP1/2 on damaged DNA, and it has been approved by the US FDA for the treatment of metastatic germline BRCA1/2 mutated breast cancers in October 2018. The talazoparib side effect profile more closely resembles traditional chemotherapeutics rather than other clinically approved PARP inhibitors. In this review, we discuss the scientific evidence that has emerged from both experimental and clinical studies in the development of talazoparib. Future directions will include optimizing combination therapy with chemotherapy, immunotherapies and targeted therapies, and in developing and validating biomarkers for patient selection and stratification, particularly in malignancies with 'BRCAness'

Management of Metastatic Spinal Cord Compression in Secondary Care: A Practice Reflection from Medway Maritime Hospital, Kent, UK

Introduction: Malignant spinal cord compression (MSCC) is one of the most devastating complications of cancer. This event requires rapid decision-making on the part of several specialists, given the risk of permanent spinal cord injury or death. The goals of treatment in spinal metastases are pain control and improvement of neurological function. There can be challenges in delivering prompt diagnosis and treatment in a secondary care setting. We have reflected on the experience of managing MSCC in a district general setting. Aim: Our retrospective audit identified 53 patients with suspected MSCC who entered the relevant pathway from April 2017 to March 2018 at Medway, United Kingdom (UK). Our audit standards were set out by Medway Maritime Hospital and Maidstone and Tunbridge Wells NHS Trust MSCC working group members, using a combination of published evidence and best practice. Results: The patients with suspected MSCC were 53 and 29 of them (54.7%) had confirmed MSCC. The most common malignancies within the confirmed MSCC were lung (11 patients, 37.9%), breast (5 patients 17.2%), and renal (3 patients, 10.3%), followed by prostate, myeloma and carcinoma of unknown primary (2 patients (6.9%) each), as well as pancreatic, colorectal, lymphoma and, bladder (1 patient (3.4%) each). A magnetic resonance imaging (MRI) scan was performed in 48 patients (90.5%); the majority (31 patients, 64.6%) underwent the MRI within the first 24 h, whereas 3 patients had the investigation between 24 and 72 h from the admission. Among the 29 patients with confirmed MSCC, 6 (20.6%) were treated with surgical decompression, while 20 (69%) received radiotherapy (RT) and 3 (10.3%) best supportive care, respectively. Median time to surgery was 5 days (ranged between 2 and 8 days), whereas for RT 44.4 h (ranged between 24 and 72 h). Finally, all 3 patients that decided on symptom control were referred to a palliative care team within the first 24 h following the MRI scan. Conclusions: MSCC is frequently presented outside tertiary care. This may cause subsequent delays in investigation, diagnosis, and treatment, which can be improved by following a fast track referral pathway