Imatinib in combination with phosphoinositol kinase inhibitor buparlisib in patients with gastrointestinal stromal tumour who failed prior therapy with imatinib and sunitinib: a Phase 1b, multicentre study
BRITISH JOURNAL OF CANCER
Authors: Gelderblom, Hans; Jones, Robin L.; George, Suzanne; Morales, Claudia Valverde; Benson, Charlotte; Blay, Jean-Yves; Renouf, Daniel J.; Doi, Toshihiko; Le Cesne, Axel; Leahy, Michael; Hertle, Sabine; Aimone, Paola; Brandt, Ulrike; Schoffski, Patrick
Abstract
Background The majority of patients with advanced gastrointestinal stromal tumours (GISTs) develop resistance to imatinib and sunitinib, the standard of care for these patients. This study evaluated the combination of buparlisib, an oral phosphoinositide 3-kinase (PI3K) inhibitor, with imatinib in patients with advanced GIST, who have failed prior therapy with imatinib and sunitinib. Methods This Phase 1b, multicentre, open-label study aimed to determine the maximum tolerated dose (MTD) and/or a recommended Phase 2 dose of buparlisib in combination with 400 mg of imatinib through a dose-escalation part and a dose-expansion part, and also evaluated the clinical profile of the combination. Results Sixty patients were enrolled, including 25 in the dose-escalation part and 35 in the dose-expansion part. In the combination, MTD of buparlisib was established as 80 mg. No partial or complete responses were observed. The estimated median progression-free survival was 3.5 months in the expansion phase. Overall, 98.3% of patients had treatment-related adverse events (AEs), including 45% with grade 3 or 4 AEs. Conclusions Buparlisib in combination with imatinib provided no additional benefit compared with currently available therapies. Due to the lack of objective responses, further development of this combination was not pursued for third-line/fourth-line advanced/metastatic GIST.
US Phase I First-in-human Study of Taletrectinib (DS-6051b/AB-106), a ROS1/TRK Inhibitor, in Patients with Advanced Solid Tumors
CLINICAL CANCER RESEARCH
Authors: Papadopoulos, Kyriakos P.; Borazanci, Erkut; Shaw, Alice T.; Katayama, Ryohei; Shimizu, Yuki; Zhu, Viola W.; Sun, Thomas Yang; Wakelee, Heather A.; Madison, Russell; Schrock, Alexa B.; Senaldi, Giorgio; Nakao, Naoki; Hanzawa, Hiroyuki; Tachibana, Masaya; Isoyama, Takeshi; Nakamaru, Kenji; Deng, Chenhui; Li, Meijing; Fan, Frank; Zhao, Qinying; Gao, Yanfei; Seto, Takashi; Janne, Pasi A.; Ou, Sai-Hong Ignatius
Abstract
Purpose: Taletrectinib ( DS-6051b/AB-106) is an oral, tyrosine kinase inhibitor of ROS1 and NTRK with potent preclinical activity against ROS1 G2032R solvent-front mutation among others. We report the first-in-human U.S. phase I results of taletrectinib. Patients and Methods: Patients >= 18 years old with neuroendocrine tumors, with tumor-induced pain, or tumors harboring ROS1/NTRK rearrangements were eligible. Accelerated titration followed by modified continuous reassessment method and escalation with overdose control was used (50-1,200 mg once daily or 400 mg twice daily). Primary objectives were safety/tolerability, and MTD determination. Secondary objectives were food-effect pharmacokinetics and antitumor activity. Results: A total of 46 patients were enrolled. Steady-state peak concentration (C-max) and exposure (AUC0-8) increased dose dependently from 50-mg to 800-mg once-daily doses. The ratio of the geometric mean of AUC0- 24 between low-fat-diet-fed/fasted state was 123% (90% confidence interval, 104%-149%). Doselimiting toxicities (grade 3 transaminases increase) occurred in two patients (1,200-mg once-daily dose). MTD was 800 mg once daily. Most common treatment-related adverse events were nausea (47.8%), diarrhea (43.5%), and vomiting (32.6%). Pain score reductions were observed in the 800-mg once-daily dose cohort. Confirmed objective response rate was 33.3% among the six patients with RECIST-evaluable crizotinib-refractory ROS1+ NSCLC. One patient with TPM3-NTRK1 differentiated thyroid cancer achieving a confirmed partial response of 27 months at data cutoff. We identified a cabozantinib-sensitive ROS1 L2086F as an acquired taletrectinib-resistance mutation. Conclusions: Taletrectinib has manageable toxicities at the MTD of 800 mg daily. Preliminary efficacy was observed in patients with crizotinib-refractory ROS1(+) NSCLC.