Therapeutic drug monitoring-based precision dosing of oral targeted therapies in oncology: a prospective multicenter study.

BACKGROUND: Oral targeted therapies show a high pharmacokinetic (PK) interpatient variability. Even though exposure has been positively correlated with efficacy for many of these drugs, these are still dosed using a one-size-fits-all approach. Consequently, individuals have a high probability to be either underexposed or overexposed, potentially leading to suboptimal outcomes. Therapeutic drug monitoring, which is personalized dosing based on measured systemic drug concentrations, could address these problems. PATIENTS AND METHODS: Patients were enrolled in this prospective multicenter study (www.trialregister.nl; NL6695) if they started treatment with one of the 24 participating oral targeted therapies. Primary outcome was to halve the proportion of underexposed patients, compared with historical data. PK sampling was carried out after 4, 8 and 12 weeks, and every 12 weeks thereafter. In case of Cmin below the predefined target and manageable toxicity, a pharmacokinetically guided intervention was proposed (i.e. checking compliance and drug-drug interactions, concomitant intake with food, splitting intake moments or dose increments). RESULTS: In total, 600 patients were included of whom 426 patients are assessable for the primary outcome and 552 patients had ≥1 PK sample(s) available and were therefore assessable for the overall analyses. Pharmacokinetically guided dosing reduced the proportion of underexposed patients at the third PK measurement by 39.0% (95% confidence interval 28.0% to 49.0%) compared with historical data. At the third PK measurement, 110 out of 426 patients (25.8%) had a low exposure. In total, 294 patients (53.3%) had ≥1 PK sample(s) below the preset target at a certain time point during treatment. In 166 of these patients (56.5%), pharmacokinetically guided interventions were carried out, which were successful in 113 out of 152 assessable patients (74.3%). CONCLUSIONS: Pharmacokinetically guided dose optimization of oral targeted therapies was feasible in clinical practice and reduced the proportion of underexposed patients considerably.

Predicting postoperative complications and their impact on quality of life and functional status in older patients with breast cancer.

BACKGROUND: The percentage of older patients undergoing surgery for early-stage breast cancer has decreased over the past decade. This study aimed to develop a prediction model for postoperative complications to better inform patients about the benefits and risks of surgery, and to investigate the association between complications and functional status and quality of life (QoL). METHODS: Women aged at least 70 years who underwent surgery for Tis-3 N0 breast cancer were included between 2013 and 2018. The primary outcome was any postoperative complication within 30 days after surgery. Secondary outcomes included functional status and QoL during the first year after surgery, as assessed by the Groningen Activity Restriction Scale and the European Organisation for Research and Treatment of Cancer QLQ-C30 and QLQ-BR23 questionnaires. A prediction model was developed using multivariable logistic regression and validated externally using data from the British Bridging the Age Gap Study. Linear mixed models were used to assess QoL and functional status over time. RESULTS: The development and validation cohorts included 547 and 2727 women respectively. The prediction model consisted of five predictors (age, polypharmacy, BMI, and type of breast and axillary surgery) and performed well in internal (area under curve (AUC) 0.76, 95 per cent c.i. 0.72 to 0.80) and external (AUC 0.70, 0.68 to 0.72) validations. Functional status and QoL were not affected by postoperative complication after adjustment for confounders. CONCLUSION: This validated prediction model can be used to counsel older patients with breast cancer about the postoperative phase. Postoperative complications did not affect functional status nor QoL within the first year after surgery even after adjustment for predefined confounders.

Surgery remains the standard of care for the majority of older patients with breast cancer. The percentage of older patients with breast cancer receiving surgery is decreasing. The reason for this decline is unknown, but it might be due to fear of complications. To better inform patients about the benefits and risks of surgery, the aim of this study was to develop a prediction model for complications after surgery. Another important aspect, especially for older adults with breast cancer, is quality of life, functional capacity, and ability to carry out daily tasks (functional status) after therapy. This study showed that quality of life and functional status did not decline after breast surgery, irrespective of the occurrence of postoperative complications.

Feasibility and effectiveness of trifluridine/tipiracil in metastatic colorectal cancer: real-life data from The Netherlands.

BACKGROUND: The RECOURSE trial showed clinical efficacy for trifluridine/tipiracil for refractory metastatic colorectal cancer patients. We assessed the feasibility and effectiveness of trifluridine/tipiracil in daily clinical practice in The Netherlands. METHODS: Medical records of patients from 17 centers treated in the trifluridine/tipiracil compassionate use program were reviewed and checked for RECOURSE eligibility criteria. Baseline characteristics, safety, and survival times were compared, and prespecified baseline characteristics were tested in multivariate analyses for prognostic significance on overall survival (OS). RESULTS: A total of 136 patients with a median age of 62 years were analyzed. Forty-three patients (32%) did not meet the RECOURSE eligibility criteria for not having received all prior standard treatments (n = 35, 26%) and/or ECOG performance status (PS) 2 (n = 12, 9%). The most common grade ≥3 toxicities were neutropenia (n = 44, 32%), leukopenia (n = 8, 6%), anemia (n = 7, 5%), and fatigue (n = 7, 5%). Median progression-free survival (PFS) and median OS were 2.1 (95% CI, 1.8-2.3) and 5.4 months (95% CI, 4.0-6.9), respectively. Patients with ECOG PS 2 had a worse median OS (3.2 months) compared to patients with ECOG PS 0-1 (5.9 months). ECOG PS, KRAS-mutation status, white blood cell count, serum lactate dehydrogenase, and alkaline phosphatase were prognostic factors for OS. CONCLUSIONS: Our data show that treatment with trifluridine/tipiracil in daily clinical practice is feasible and safe. Differences in patient characteristics between our population and the RECOURSE study population should be taken into account in the interpretation of survival data. Our results argue against the use of trifluridine/tipiracil in patients with ECOG PS 2. FUNDING: Johannes J.M. Kwakman received an unrestricted research grant from Servier.

Clinical outcomes of definitive chemoradiotherapy using carboplatin and paclitaxel in esophageal cancer.

Patients with nonmetastatic esophageal cancer not suitable for surgery can be treated with definitive chemoradiotherapy with curative intent. The purpose of this retrospective study is to evaluate the clinical outcomes of definitive chemoradiotherapy using carboplatin and paclitaxel. Medical records were reviewed of patients treated for nonmetastatic squamous cell or adenocarcinoma of the esophagus between January 2009 and December 2013 in two collaborating institutes. Treatment consisted of external beam radiotherapy (28 fractions of 1.8 Gy) and 6 weekly courses of carboplatin (AUC = 2) and paclitaxel (50 mg/m2). Data on survival, progression, toxicity, and effect on dysphagia were recorded. Sixty-six patients were included. Median overall survival (OS) was 13.1 months (95% CI 4.7-21.5 months) and a 2-year OS was 30% (95% CI 18%-42%). At 2 years, 26% of patients developed local progression (95% CI 15%-37%) and 49% developed distant metastases (95% CI 36%-64%). Acute toxicity grade ≥3 was observed in 47% of patients. Late adverse events grade ≥3 were seen in 20%, mostly esophageal stenoses. Of patients with available data 3 months after treatment, 70% had relief of dysphagia. Definitive chemoradiotherapy led to a median OS of 13 months. Toxicity was common, mostly due to hematological toxicity. Given the relatively short median survival, an adequate selection of patients for this intensive treatment is required.