Immune Checkpoint Inhibitors Have Clinical Activity in Patients With Recurrent Chordoma

The aim of this study is to evaluate the outcomes and tolerance of immune checkpoint inhibitors (ICIs) for patients with recurrent chordoma. We reviewed the records of 17 patients with recurrent chordomas who received ICIs for progressing disease as part of their treatment between 2016 and 2020. Response was assessed using response evaluation criteria in solid tumors 1.1 criteria. The Kaplan-Meier method was used to estimate the duration of response, progression-free survival (PFS), and overall survival (OS). Clinical benefit was defined as having stable disease (SD), a partial response, or a complete response. The median follow-up from the start of ICIs was 29 months [interquartile range (IQR): 13-35 m]. The majority received pembrolizumab (n=9, 53%), and the median number of cycles delivered was 8 (IQR: 7-12). The 1-year OS was 87%, and the 1-year PFS was 56% with a median PFS of 14 months (95% CI, 5-17 mo). After ICI initiation, most patients (n=15, 88%) had clinical benefit consisting of a complete response (n=1, 6%), partial response (n=3, 18%), and stable disease (n=11, 65%). Among all responders (n=15), the median duration of response was 12 months. Toxicities were limited: 2 (12%) patients having grade 3/4 immune-related toxicities (colitis, grade 3; myocarditis, grade 4). We observed a high rate of clinical benefit and favorable durability from ICI use for patients with recurrent chordoma. These data provide support for the integration of ICIs as a standard first-line systemic therapy option for patients with recurrent chordoma. Prospective studies are warranted to further evaluate efficacy and enhance response rates.

Effects of barbital on neuro-oncogenesis in a transplacental carcinogenicity model using F344 rats

Effects of barbital (BB) on neuro-oncogenesis were examined in a rat transplacental carcinogenesis model. Pregnant F344 rats were divided into 7 groups. Dams in group I received subcutaneous injections of 10 mg/rat 1-butyl-1-nitrosourea (BNU) on the days 15, 18 and 21 of pregnancy and dams in groups II-IV, 1mg/rat BNU on the same time schedule. In addition to the treatment with BNU, dams in group IV were given 0.125% BB solution as their drinking water from the day 12 of pregnancy to parturition. Offspring in groups III and IV received 0.125% BB solution as drinking water from 4 weeks of age until the termination of the study. Animals in groups V and VI were given 0.25% and 0.125% BB solutions, respectively, in the peri- and postnatal period without BNU treatment. Dams in group VII received 250 mg/kg BB subcutaneously on the days 15, 18 and 21 of pregnancy. Offspring in all groups were observed until 105-116 weeks of age. High yields of neurogenic tumors, such as gliomas and neurinomas, were observed in group I. In groups II, III and IV, single cases of a chordoma, a granular cell tumor, and a neurinoma and a malignant reticulosis, which are known to occur spontaneously, were noted, although no gliomas were found. No neurogenic tumors were observed in groups V-VII. With regard to lesions other than those in neurogenic organs, a significant increase in liver tumors was observed in group III compared to group II. In contrast, lung tumors were not found in group III, while they were observed in groups II and IV. These results suggest that BB has no neuro-carcinogenic activity in the rat transplacental carcinogenesis model.