Efficacy of second and third lines of treatment in advanced soft tissue sarcomas: a real-world study

BACKGROUND

Soft tissue sarcomas (STSs) are an uncommon and heterogeneous group of tumours. Several drugs and combinations have been used in clinical practice as second-line (2L) and third-line (3L) treatment. The growth modulation index (GMI) has previously been used as an exploratory efficacy endpoint of drug activity and represents an intra-patient comparison.

METHODS

We performed a real-world retrospective study including all patients with advanced STS who had received at least 2 different lines of treatment for advanced disease between 2010 and 2020 at a single institution. The objective was to study the efficacy of both 2L and 3L treatments, analysing the time to progression (TTP) and the GMI (defined as the ratio of TTP between 2 consecutive lines of therapy).

RESULTS

Eighty-one patients were included. The median TTP after 2L and 3L treatment was 3.16 and 3.06 months, and the median GMI was 0.81 and 0.74, respectively. The regimens most frequently used in both treatments were trabectedin, gemcitabine-dacarbazine, gemcitabine-docetaxel, pazopanib and ifosfamide. The median TTP by each of these regimens was 2.80, 2.23, 2.83, 4.10, and 5.00 months, and the median GMI was 0.78, 0.73, 0.67, 1.08, and 0.94, respectively. In terms of histotype, we highlight the activity (GMI > 1.33) of gemcitabine-dacarbazine in undifferentiated pleomorphic sarcoma (UPS) and in leiomyosarcoma, pazopanib in UPS, and ifosfamide in synovial sarcoma.

CONCLUSIONS

In our cohort, regimens commonly used after first-line STS treatment showed only slight differences in efficacy, although we found significant activity of specific regimens by histotype.

Optimization of screening tools in patients eligible to receive immune-checkpoint inhibitors

e14139

Background: The management of immune-related adverse events (irAEs) produced by immune-checkpoint inhibitors can be challenging, considering differences with the toxicity of classical chemotherapy. In this study, we explored the limitations in the preventions and diagnosis of irAEs at our institution and developed a strategic plan to solve them according to guidelines of the European Society for Medical Oncology and the American Society of Clinical Oncology. Methods: This is a two-phase, single center, exploratory study. In the first phase, we analyzed a random sample of 20 patients (pts) treated with nivolumab or pembrolizumab in the years 2017-2018. A Pareto chart was designed to identify issues in the baseline screening, as well as potential ways to improve the management of irAEs. After that, we implemented corrective measures based on educational lectures, early identification of patients eligible for immunotherapy, standardized protocols, and a profile of screening tests in the electronic medical records. We applied the new strategy on 15 pts treated from January-April 2019. To compare the impact of the implemented measures we used a run chart, frequencies/percentages for categorical variables, and medians/ranges for continuous variables. Adverse events were assessed according to CTCAEv5.0. Results: In the first phase, 38% of the required tests were done before the start of immunotherapy. We identified a deficit in the evaluation of cardiac and pulmonary function, chronic infections, and skin disorders. 45% of pts had some irAEs (15% G1, 15% G2 and 15% G3). Due to toxicity, 33% of pts had delays in the administration of treatment, and 11% required early interruption. After applying corrective measures, 81% of tests were requested before treatment initiation. However, screening for tuberculosis infection and echocardiogram continued to be deficient. We identified irAEs in 53% of pts (16% G1, 50% G2 and 25% G3), and 37% of them presented two or more different irAEs during the period of treatment. 37,5% and 12,5% of pts had delays or early interruption of immunotherapy, respectively. All of pts with irAEs had presented any basal alterations in screening tests. The most frequent basal alterations were found in pancreatic (66%) and thyroid activity (50%). Conclusions: Simple improvement strategies such as education programs, standardized protocols, and an electronic profile can improve the basal screening for potential irAEs. The basal alterations found in some pts can be related to the development of side effects or interactions with the immunotherapy.