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