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Background: In the phase 3 GRID trial, regorafenib improved progression-free survival (PFS) independent of KIT mutations in exons 9 and 11. In this retrospective, exploratory analysis of the GRID trial, we investigated whether a more comprehensive KIT mutation analysis could identify mutations that impact treatment outcome with regorafenib and a regorafenib-induced mutation pattern., Methods: Archived tumor samples, collected at any time prior to enrollment in GRID, were analyzed by Sanger sequencing (n = 102) and next-generation sequencing (FoundationONE; n = 47). Plasma samples collected at baseline were analyzed by BEAMing (n = 163) and SafeSEQ (n = 96)., Results: In archived tumor samples, 67% (68/102) had a KIT mutation; 61% (62/102) had primary KIT mutations (exons 9 and 11) and 12% (12/102) had secondary mutations (exons 13, 14, 17, and 18). At baseline, 81% of samples (78/96) had KIT mutations by SafeSEQ, including the M541L polymorphism (sole event in 6 patients). Coexisting mutations in other oncogenes were rare, as were mutations in PDGFR, KRAS, and BRAF. Regorafenib showed PFS benefit across all primary and secondary KIT mutational subgroups examined. Available patient-matched samples taken at baseline and end of treatment (n = 41; SafeSEQ), revealed heterogeneous KIT mutational changes with no specific mutation pattern emerging upon regorafenib treatment., Conclusion: These data support the results of the GRID trial, and suggest that patients may benefit from regorafenib in the presence of KIT mutations and without the selection of particular mutation patterns that confer resistance. The study was not powered to address biomarker-related questions, and the results are exploratory and hypothesis-generating., (© 2022. The Author(s).)

Background: Darolutamide, an androgen receptor antagonist with a distinct molecular structure, significantly prolonged metastasis-free survival versus placebo in the phase III ARAMIS study in men with nonmetastatic castration-resistant prostate cancer (nmCRPC). In this population, polypharmacy for age-related comorbidities is common and may increase drug-drug interaction (DDI) risks. Preclinical/phase I study data suggest darolutamide has a low DDI potential-other than breast cancer resistance protein/organic anion transporter protein substrates (e.g., statins), no clinically relevant effect on comedications is expected., Objective: Our objective was to evaluate the effect of commonly administered drugs on the pharmacokinetics of darolutamide and the effect of comedications potentially affected by darolutamide on safety in patients with nmCRPC., Patients and Methods: Comorbidities and comedication use in the 1509 ARAMIS participants treated with darolutamide 600 mg twice daily or placebo were assessed. A population pharmacokinetic analysis evaluated whether comedications affected the pharmacokinetics of darolutamide in a subset of 388 patients. A subgroup analysis of adverse events (AEs) in statin users versus nonusers was conducted., Results: Most participants (median age 74 years) had at least one comorbidity (98.4% in both arms) and used at least one comedication (98.7% with darolutamide vs. 98.0% with placebo); these were similar across study arms. Despite frequent use of comedications with DDI potential, no significant effects on darolutamide pharmacokinetics were identified. Comedications included lipid-modifying agents (34.5%), β-blockers (29.7%), antithrombotics (42.8%), and systemic antibiotics (26.9%). AE incidence was similar across study arms in statin users and nonusers. Study limitations include the small sample size for sub-analyses., Conclusions: These analyses suggest the pharmacokinetic profile of darolutamide is not affected by a number of commonly administered drugs in patients with nmCRPC. Although pharmacokinetic data have indicated that darolutamide has the potential to interact with rosuvastatin, used to assess DDI in these studies, this finding did not seem to translate into increased AEs due to statin use in the ARAMIS trial. Clinicaltrials.gov identifier: NCT02200614.

Background: The randomized, double-blind, placebo-controlled GRID trial tested the oral multikinase inhibitor regorafenib in 199 patients with advanced gastrointestinal stromal tumors (GIST) following failure of at least imatinib and sunitinib, and showed a significant improvement in progression-free survival (PFS) versus placebo [hazard ratio (HR) 0.27; 95 % confidence interval (CI) 0.19-0.39; p < 0.0001]., Methods: A subgroup analysis of Japanese patients in the GRID study was performed to compare the efficacy and safety of oral regorafenib 160 mg once daily with matching placebo, in combination with best supportive care. The primary study endpoint was progression-free survival (PFS); safety was evaluated through the incidence of adverse events (AEs)., Results: Seventeen Japanese patients were randomized to regorafenib (n = 12) or placebo (n = 5). Patient demographics were consistent with those of the overall study population. PFS was significantly longer with regorafenib than placebo (HR 0.08; 95 % CI 0.02-0.45; p = 0.000164). Centrally assessed disease control rates were 58 % and 20 % in the regorafenib and placebo groups, respectively (p = 0.080796). Treatment-related adverse events (AEs) were reported in all regorafenib-treated patients and 60 % of placebo recipients; the most frequent AE was hand-foot skin reaction (HFSR) (92 % versus 20 %, respectively)., Conclusion: Regorafenib showed efficacy and a manageable safety profile in Japanese patients with advanced GIST, consistent with the overall GRID study population. AEs, such as HFSR and maculopapular rash, were observed more frequently in Japanese patients. Although dose modification was frequently reported, only one patient with hepatic failure discontinued regorafenib because of AEs.

Background: Until now, only imatinib and sunitinib have proven clinical benefit in patients with gastrointestinal stromal tumours (GIST), but almost all metastatic GIST eventually develop resistance to these agents, resulting in fatal disease progression. We aimed to assess efficacy and safety of regorafenib in patients with metastatic or unresectable GIST progressing after failure of at least imatinib and sunitinib., Methods: We did this phase 3 trial at 57 hospitals in 17 countries. Patients with histologically confirmed, metastatic or unresectable GIST, with failure of at least previous imatinib and sunitinib were randomised in a 2:1 ratio (by computer-generated randomisation list and interactive voice response system; preallocated block design (block size 12); stratified by treatment line and geographical region) to receive either oral regorafenib 160 mg daily or placebo, plus best supportive care in both groups, for the first 3 weeks of each 4 week cycle. The study sponsor, participants, and investigators were masked to treatment assignment. The primary endpoint was progression-free survival (PFS). At disease progression, patients assigned placebo could crossover to open-label regorafenib. Analyses were by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01271712., Results: From Jan 4, to Aug 18, 2011, 240 patients were screened and 199 were randomised to receive regorafenib (n=133) or matching placebo (n=66). Data cutoff was Jan 26, 2012. Median PFS per independent blinded central review was 4·8 months (IQR 1·4-9·2) for regorafenib and 0·9 months (0·9-1·8) for placebo (hazard ratio [HR] 0·27, 95% CI 0·19-0·39; p<0·0001). After progression, 56 patients (85%) assigned placebo crossed over to regorafenib. Drug-related adverse events were reported in 130 (98%) patients assigned regorafenib and 45 (68%) patients assigned placebo. The most common regorafenib-related adverse events of grade 3 or higher were hypertension (31 of 132, 23%), hand-foot skin reaction (26 of 132, 20%), and diarrhoea (seven of 132, 5%)., Interpretation: The results of this study show that oral regorafenib can provide a significant improvement in progression-free survival compared with placebo in patients with metastatic GIST after progression on standard treatments. As far as we are aware, this is the first clinical trial to show benefit from a kinase inhibitor in this highly refractory population of patients., Funding: Bayer HealthCare Pharmaceuticals., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

A total of 50 patients were treated weekly with 5-fluorouracil (FU), leucovorin (LV), and 4'-O-tetrahydropyranyl-doxorubicin (THP) as first-line chemotherapy for advanced breast cancer (ABC). In phase I the doses of LV (500 mg/m2, day 1) and FU (350 mg/m2, day 1) were held constant, while the dose of THP (day 1) was escalated, from the initial dose of 10 mg/m2 up to the maximum tolerated dose (MTD). Twenty-eight patients entered phase I, and MTD for THP was defined as 35 mg/m2 in this combination. Dose-limiting toxicities were myelosuppression and hepatotoxicity. In phase II, another 22 patients were treated with THP at a dose level of 30 mg/m2. Including 4 patients already treated at this dose in the first part, 25 patients were evaluable for response: 1 patient obtained a complete response (CR) and 13 showed a partial response (PR), giving an objective response rate of 56%. The median duration of response was 9.1+ months and median survival, 15.5+ months. Side effects were generally mild, with ECOG grade I and II leukopenia in 51% of all cycles and grade III in 3% of the courses. Other toxicity included nausea and vomiting (54% and 8%, respectively) and alopecia (24%), all restricted to ECOG grade I and II. Our results suggest that weekly THP/LV-FU represents an active regimen for first-line treatment of ABC with relative low toxicity. [ABSTRACT FROM AUTHOR]