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.