First reported double drug-drug interaction in a cancer renal patient under everolimus treatment: therapeutic drug monitoring and review of literature.

Everolimus is an inhibitor of mammalian target of rapamycin (mTOR) used in both transplantation and cancer treatment (breast, renal and neuroendocrine). In transplantation, therapeutic drug monitoring (TDM) is recommended due to the potential drug-drug interactions with chronic medications, which can affect everolimus pharmacokinetics. In cancer treatment, everolimus is used at higher doses than in transplantation and without a systematic drug monitoring.We present a case report of a 72-year-old woman with epilepsy history to whom everolimus 10 mg QD was prescribed as third line of treatment for renal cell carcinoma (RCC). The potential drug interactions between everolimus and the patient's chronic medications, carbamazepine and phenytoin, are significant as both are known as strong inducers CYP3A4 metabolism, potentially leading to underexposure to everolimus.TDM of everolimus was recommended by the pharmacist. The literature suggests that a minimum plasma concentration (Cminss) of everolimus over 10 ng/ml is associated with better response to treatment and progression-free survival (PFS). The patient's everolimus dose had to be increased until 10 mg BID, and regular monitoring of everolimus levels showed an increase in Cminss from 3.7 ng/ml to 10.8 ng/ml.This case highlights the importance of checking for potential drug interactions and monitoring everolimus levels in patients on chronic medication, especially those with several inducers or inhibitors of CYP3A4 metabolism. TDM can help to ensure that patients are treated with their optimal dose, which can improve the effectiveness of the treatment or minimize the risk of toxicities.

Long-Term Cardiac Safety and Survival Outcomes of Neoadjuvant Pegylated Liposomal Doxorubicin in Elderly Patients or Prone to Cardiotoxicity and Triple Negative Breast Cancer. Final Results of the Multicentre Phase II CAPRICE Study.

BACKGROUND: The CAPRICE trial was designed to specifically evaluate neoadjuvant pegylated liposomal doxorubicin (PLD) in elderly patients or in those with other cardiovascular risk factors in whom conventional doxorubicin was contraindicated. The primary analysis of the study showed a pathological complete response (pCR) of 32% and no significant decreases in LVEF during chemotherapy. Here, we report important secondary study objectives: 5-year cardiac safety, disease-free survival (DFS), overall survival (OS) and breast cancer specific survival (BCSS). METHODS: In this multicentre, single-arm, phase II trial, elderly patients or those prone to cardiotoxicity and high risk stage II-IIIB breast cancer received PLD (35 mg/m2) plus cyclophosphamide (600 mg/m2) every 4 weeks for 4 cycles, followed by paclitaxel for 12 weeks as neoadjuvant chemotherapy (NAC). Left ventricular ejection fraction (LVEF) monitorization, electrocardiograms and cardiac questionnaires were performed at baseline, during treatment and at 9, 16, 28 and 40 weeks thereafter. The primary endpoint was pCR and 5-year cardiac safety, DFS, BCSS and OS were also analyzed. RESULTS: Between Oct 2007, and Jun 2010, 50 eligible patients were included. Median age was 73 (35-84) years, 84% were older than 65; 64% of patients suffered from hypertension, and 10% had prior cardiac disease. Most of tumors (88%) were triple negative. No significant decreases in LVEF were observed. The mean baseline LVEF was 66.6% (52-86) and after a median follow-up of 5 years, mean LVEF was 66 (54.5-73). For intention to treat population, 5-year DFS was 50% (95% CI 40.2-68.1) and 5-year OS was 56% (95%CI 41.2-68.4). There were 8 non-cancer related deaths, achieving a 5 years BCSS of 67.74% (CI 95%:54.31%- 81.18%). CONCLUSION: At 5-year follow-up, this PLD-based NAC regimen continued to be cardiac-safe and effective in a population of very high-risk breast cancer patients. This scheme should be considered as an option in elderly patients or in those with other risks of developing cardiotoxicity. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov reference NCT00563953.

Phase 2 study of buparlisib (BKM120), a pan-class I PI3K inhibitor, in patients with metastatic triple-negative breast cancer.

BACKGROUND: Treatment options for triple-negative breast cancer remain limited. Activation of the PI3K pathway via loss of PTEN and/or INPP4B is common. Buparlisib is an orally bioavailable, pan-class I PI3K inhibitor. We evaluated the safety and efficacy of buparlisib in patients with metastatic triple-negative breast cancer. METHODS: This was a single-arm phase 2 study enrolling patients with triple-negative metastatic breast cancer. Patients were treated with buparlisib at a starting dose of 100 mg daily. The primary endpoint was clinical benefit, defined as confirmed complete response (CR), partial response (PR), or stable disease (SD) for ≥ 4 months, per RECIST 1.1. Secondary endpoints included progression-free survival (PFS), overall survival (OS), and toxicity. A subset of patients underwent pre- and on-treatment tumor tissue biopsies for correlative studies. RESULTS: Fifty patients were enrolled. Median number of cycles was 2 (range 1-10). The clinical benefit rate was 12% (6 patients, all SD ≥ 4 months). Median PFS was 1.8 months (95% confidence interval [CI] 1.6-2.3). Median OS was 11.2 months (95% CI 6.2-25). The most frequent adverse events were fatigue (58% all grades, 8% grade 3), nausea (34% all grades, none grade 3), hyperglycemia (34% all grades, 4% grade 3), and anorexia (30% all grades, 2% grade 3). Eighteen percent of patients experienced depression (12% grade 1, 6% grade 2) and anxiety (10% grade 1, 8% grade 2). Alterations in PIK3CA/AKT1/PTEN were present in 6/27 patients with available targeted DNA sequencing (MSK-IMPACT), 3 of whom achieved SD as best overall response though none with clinical benefit ≥ 4 months. Of five patients with paired baseline and on-treatment biopsies, reverse phase protein arrays (RPPA) analysis demonstrated reduction of S6 phosphorylation in 2 of 3 patients who achieved SD, and in none of the patients with progressive disease. CONCLUSIONS: Buparlisib was associated with prolonged SD in a very small subset of patients with triple-negative breast cancer; however, no confirmed objective responses were observed. Downmodulation of key nodes in the PI3K pathway was observed in patients who achieved SD. PI3K pathway inhibition alone may be insufficient as a therapeutic strategy for triple-negative breast cancer. TRIAL REGISTRATION: NCT01790932 . Registered on 13 February 2013; NCT01629615 . Registered on 27 June 2012.

Ribociclib plus letrozole versus chemotherapy for postmenopausal women with hormone receptor-positive, HER2-negative, luminal B breast cancer (CORALLEEN): an open-label, multicentre, randomised, phase 2 trial.

BACKGROUND: In hormone receptor-positive, HER2-negative early stage breast cancer, cyclin-dependent kinases 4 and 6 (CDK4/6) inhibition in combination with endocrine therapy could represent an alternative to multiagent chemotherapy. We aimed to evaluate the biological and clinical activity of neoadjuvant ribociclib plus letrozole in the luminal B subtype of early stage breast cancer. METHODS: CORALLEEN is a parallel-arm, multicentre, randomised, open-label, phase 2 trial completed across 21 hospitals in Spain. We recruited postmenopausal women (≥18 years) with stage I-IIIA hormone receptor-positive, Eastern Cooperative Oncology Group Performance Status 0-1, HER2-negative breast cancer and luminal B by PAM50 with histologically confirmed, operable primary tumour size of at least 2 cm in diameter as measured by MRI. Patients were randomly assigned (1:1) using a web-based system and permuted blocks of 25 to receive either six 28-days cycles of ribociclib (oral 600 mg once daily for 3 weeks on, 1 week off) plus daily letrozole (oral 2·5 mg/day) or four cycles of doxorubicin (intravenous 60 mg/m2) and cyclophosphamide (intravenous 600 mg/m2) every 21 days followed by weekly paclitaxel (intravenous 80 mg/m2) for 12 weeks. The total duration of the neoadjuvant therapy was 24 weeks. Randomisation was stratified by tumour size and nodal involvement. Samples were prospectively collected at baseline (day 0), day 15, and surgery. The primary endpoint was to evaluate the proportion of patients with PAM50 low-risk-of-relapse (ROR) disease at surgery in the modified intention-to-treat population including all randomly assigned patients who received study drug and had a baseline and at least one post-baseline measurement of ROR score. The PAM50 ROR risk class integrated gene expression data, tumour size, and nodal status to define prognosis. This trial was registered at ClinicalTrials.gov, NCT03248427. FINDINGS: Between July 27, 2017 to Dec 7, 2018, 106 patients were enrolled. At baseline, of the 106 patients, 92 (87%) patients had high ROR disease (44 [85%] of 52 in the ribociclib and letrozole group and 48 [89%] of 54 in the chemotherapy group) and 14 (13%) patients had intermediate-ROR disease (eight [15%] and six [11%]). Median follow-up was 200·0 days (IQR 191·2-206·0). At surgery, 23 (46·9%; 95% CI 32·5-61·7) of 49 patients in the ribociclib plus letrozole group and 24 (46·1%; 32·9-61·5) of 52 patients in the chemotherapy group were low-ROR. The most common grade 3-4 adverse events in the ribociclib plus letrozole group were neutropenia (22 [43%] of 51 patients) and elevated alanine aminotransferase concentrations (ten [20%]). The most common grade 3-4 adverse events in the chemotherapy group were neutropenia (31 [60%] of 52 patients) and febrile neutropenia (seven [13%]). No deaths were observed during the study in either group. INTERPRETATION: Our results suggest that some patients with high-risk, early stage, hormone receptor-positive, HER2-negative breast cancer could achieve molecular downstaging of their disease with CDK4/6 inhibitor and endocrine therapy. FUNDING: Novartis, Nanostring, Breast Cancer Research Foundation-AACR Career Development Award.

Palbociclib and ribociclib in breast cancer: consensus workshop on the management of concomitant medication.

Drug-drug interactions are of significant concern in clinical practice in oncology, particularly in patients receiving Cyclin-dependent kinase (CDK) 4/6 inhibitors, which are typically exposed to long-term regimens. This article presents the highlights from the 'First Workshop on Pharmacology and Management of CDK4/6 Inhibitors: Consensus about Concomitant Medications'. The article is structured into two modules. The educational module includes background information regarding drug metabolism, corrected QT (QTc) interval abnormalities, management of psychotropic drugs and a comprehensive review of selected adverse effects of palbociclib and ribociclib. The collaborative module presents the conclusions of the five working groups, each of which comprised five experts from different fields. From these conclusions positive lists of drugs for treating common comorbid conditions that can be safely administered concomitantly with palbociclib and/or ribociclib were developed.