Weekly cisplatin with or without imatinib in advanced chordoma: A retrospective case‐series analysis from the Italian Rare Cancers Network

Background To report on a retrospective case‐series analysis of weekly cisplatin (wCDDP) as a single agent or combined with imatinib (wCDDP/I) in patients with advanced chordoma treated within the Italian Rare Cancer Network. Methods Adult patients with a diagnosis of advanced, brachyury‐positive chordoma, treated from April 2007 to October 2020 with wCDDP or wCDDP/I were retrospectively identified. Imatinib was withheld at the same time as wCDDP. Response according to Response Evaluation Criteria in Solid Tumors, overall survival (OS), and progression‐free survival (PFS) were analyzed. Results Thirty‐three consecutive patients were identified (wCDDP as front‐line n = 8 [24.2%]; wCDDP as a further line n = 25 [75.8%]; prior imatinib n = 25 [75.8%]; evidence of progression before starting wCDDP n = 33). Of 32 patients evaluable for response (wCDDP, n = 22 [68.8%]; wCDDP/I, n = 10 [31.3%]), best response was stable disease (SD) in 27 patients (84.3%) and progression in 5 patients (15.6%). At a median follow‐up of 54 months, the median OS (m‐OS) was 30.3 months (interquartile range [IQR], 18.1‐56.6), the m‐PFS was 8.0 months (IQR, 5.1‐17.0), the 6‐month PFS rate was 65.2%, and the 12‐month PFS rate was 30.3%. Of 22 patients who received wCDDP, the best response was SD in 18 patients (81.8%) and progression in 4 patients (18.2%), and the m‐PFS was 8.0 months (IQR, 5.1‐17.0 months). Of 10 patients who received treatment with wCDDP/I, the best response was SD in 9 patients (90%) and progression in 1 patient (10%), and the m‐PFS was 9.3 months (IQR, 4.9‐26.5 months). Conclusions This series suggests that wCDDP, both as a single agent and combined with imatinib, has antitumor activity in chordoma. Although no dimensional responses were observed, 65% and 30% of previously progressive patients were progression‐free at 6 and 12 months, respectively. A prospective study is warranted. Weekly cisplatin, both as a single agent and combined with imatinib, has antitumor activity in advanced chordoma. These data support a prospective study to confirm the antitumor effect weekly cisplatin in this disease.