Early Changes in Circulating Cell-Free KRAS G12C Predict Response to Adagrasib in KRAS Mutant Non-Small Cell Lung Cancer Patients.

PURPOSE: Non-invasive monitoring of circulating tumor DNA (ctDNA) has the potential to be a readily available measure for early prediction of clinical response. Here, we report on early ctDNA changes of KRAS G12C in a Phase 2 trial of adagrasib in patients with advanced, KRAS G12C-mutant lung cancer. EXPERIMENTAL DESIGN: We performed serial droplet digital PCR (ddPCR) and plasma NGS on 60 KRAS G12C-mutant patients with lung cancer that participated in cohort A of the KRYSTAL-1 clinical trial. We analyzed the change in ctDNA at 2 specific intervals: Between cycles 1 and 2 and at cycle 4. Changes in ctDNA were compared with clinical and radiographic response. RESULTS: We found that, in general, a maximal response in KRAS G12C ctDNA levels could be observed during the initial approximately 3-week treatment period, well before the first scan at approximately 6 weeks. 35 patients (89.7%) exhibited a decrease in KRAS G12C cfDNA >90% and 33 patients (84.6%) achieved complete clearance by cycle 2. Patients with complete ctDNA clearance at cycle 2 showed an improved objective response rate (ORR) compared with patients with incomplete ctDNA clearance (60.6% vs. 33.3%). Furthermore, complete ctDNA clearance at cycle 4 was associated with an improved overall survival (14.7 vs. 5.4 months) and progression-free survival (HR, 0.3). CONCLUSIONS: These results support using early plasma response of KRAS G12C assessed at approximately 3 weeks to anticipate the likelihood of a favorable objective clinical response.

Adagrasib in Non-Small-Cell Lung Cancer Harboring a KRASG12C Mutation.

BACKGROUND: Adagrasib, a KRASG12C inhibitor, irreversibly and selectively binds KRASG12C, locking it in its inactive state. Adagrasib showed clinical activity and had an acceptable adverse-event profile in the phase 1-1b part of the KRYSTAL-1 phase 1-2 study. METHODS: In a registrational phase 2 cohort, we evaluated adagrasib (600 mg orally twice daily) in patients with KRASG12C -mutated non-small-cell lung cancer (NSCLC) previously treated with platinum-based chemotherapy and anti-programmed death 1 or programmed death ligand 1 therapy. The primary end point was objective response assessed by blinded independent central review. Secondary end points included the duration of response, progression-free survival, overall survival, and safety. RESULTS: As of October 15, 2021, a total of 116 patients with KRASG12C -mutated NSCLC had been treated (median follow-up, 12.9 months); 98.3% had previously received both chemotherapy and immunotherapy. Of 112 patients with measurable disease at baseline, 48 (42.9%) had a confirmed objective response. The median duration of response was 8.5 months (95% confidence interval [CI], 6.2 to 13.8), and the median progression-free survival was 6.5 months (95% CI, 4.7 to 8.4). As of January 15, 2022 (median follow-up, 15.6 months), the median overall survival was 12.6 months (95% CI, 9.2 to 19.2). Among 33 patients with previously treated, stable central nervous system metastases, the intracranial confirmed objective response rate was 33.3% (95% CI, 18.0 to 51.8). Treatment-related adverse events occurred in 97.4% of the patients - grade 1 or 2 in 52.6% and grade 3 or higher in 44.8% (including two grade 5 events) - and resulted in drug discontinuation in 6.9% of patients. CONCLUSIONS: In patients with previously treated KRASG12C -mutated NSCLC, adagrasib showed clinical efficacy without new safety signals. (Funded by Mirati Therapeutics; ClinicalTrials.gov number, NCT03785249.).

First-in-Human Phase I/IB Dose-Finding Study of Adagrasib (MRTX849) in Patients With Advanced KRASG12C Solid Tumors (KRYSTAL-1).

PURPOSE: Adagrasib (MRTX849) is an oral, highly selective, small-molecule, covalent inhibitor of KRASG12C. We report results from a phase I/IB study of adagrasib in non-small-cell lung cancer, colorectal cancer, and other solid tumors harboring the KRASG12C mutation. MATERIALS AND METHODS: Patients with advanced KRASG12C-mutant solid tumors were treated with adagrasib 150 mg orally once daily, 300 mg once daily, 600 mg once daily, 1,200 mg once daily, or 600 mg orally twice a day using an accelerated titration design, which transitioned to a modified toxicity probability interval design when a predefined degree of toxicity was observed or target adagrasib exposure was achieved. Safety, pharmacokinetics, and clinical activity were evaluated. RESULTS: Twenty-five patients were enrolled and received at least one dose of adagrasib. The recommended phase II dose (RP2D) was 600 mg twice a day on the basis of safety, tolerability, and observed pharmacokinetics properties. No maximum tolerated dose was formally defined. After a median follow-up of 19.6 months, eight of 15 patients (53.3%; 95% CI, 26.6 to 78.7) with RECIST-evaluable KRASG12C-mutant non-small-cell lung cancer treated at 600 mg twice a day achieved a confirmed partial response. The median duration of response was 16.4 months (95% CI, 3.1 to not estimable). The median progression-free survival was 11.1 months (95% CI, 2.6 to not estimable). One of two patients with KRASG12C-mutant colorectal cancer treated at 600 mg twice a day achieved a partial response (duration of response, 4.2 months). At the RP2D, the most common treatment-related adverse events (any grade) were nausea (80.0%), diarrhea (70.0%), vomiting (50.0%), and fatigue (45.0%). The most common grade 3-4 treatment-related adverse event was fatigue (15.0%). CONCLUSION: Adagrasib 600 mg twice a day was well tolerated and exhibited antitumor activity in patients with advanced solid tumors harboring the KRASG12C mutation.

The KRASG12C Inhibitor MRTX849 Provides Insight toward Therapeutic Susceptibility of KRAS-Mutant Cancers in Mouse Models and Patients.

Despite decades of research, efforts to directly target KRAS have been challenging. MRTX849 was identified as a potent, selective, and covalent KRASG12C inhibitor that exhibits favorable drug-like properties, selectively modifies mutant cysteine 12 in GDP-bound KRASG12C, and inhibits KRAS-dependent signaling. MRTX849 demonstrated pronounced tumor regression in 17 of 26 (65%) KRASG12C-positive cell line- and patient-derived xenograft models from multiple tumor types, and objective responses have been observed in patients with KRASG12C-positive lung and colon adenocarcinomas. Comprehensive pharmacodynamic and pharmacogenomic profiling in sensitive and partially resistant nonclinical models identified mechanisms implicated in limiting antitumor activity including KRAS nucleotide cycling and pathways that induce feedback reactivation and/or bypass KRAS dependence. These factors included activation of receptor tyrosine kinases (RTK), bypass of KRAS dependence, and genetic dysregulation of cell cycle. Combinations of MRTX849 with agents that target RTKs, mTOR, or cell cycle demonstrated enhanced response and marked tumor regression in several tumor models, including MRTX849-refractory models. SIGNIFICANCE: The discovery of MRTX849 provides a long-awaited opportunity to selectively target KRASG12C in patients. The in-depth characterization of MRTX849 activity, elucidation of response and resistance mechanisms, and identification of effective combinations provide new insight toward KRAS dependence and the rational development of this class of agents.See related commentary by Klempner and Hata, p. 20.This article is highlighted in the In This Issue feature, p. 1.

Correction to: Phase II study of sunitinib in Japanese patients with unresectable or metastatic, well-differentiated pancreatic neuroendocrine tumor.

In the original publication of this article, the license subtype should be CC BY and not CC BY-NC.

Mocetinostat for patients with previously treated, locally advanced/metastatic urothelial carcinoma and inactivating alterations of acetyltransferase genes.

BACKGROUND: The authors evaluated mocetinostat (a class I/IV histone deacetylase inhibitor) in patients with urothelial carcinoma harboring inactivating mutations or deletions in CREB binding protein [CREBBP] and/or E1A binding protein p300 [EP300] histone acetyltransferase genes in a single-arm, open-label phase 2 study. METHODS: Eligible patients with platinum-treated, advanced/metastatic disease received oral mocetinostat (at a dose of 70 mg 3 times per week [TIW] escalating to 90 mg TIW) in 28-day cycles in a 3-stage study (ClinicalTrials.gov identifier NCT02236195). The primary endpoint was the objective response rate. RESULTS: Genomic testing was feasible in 155 of 175 patients (89%). Qualifying tumor mutations were CREBBP (15%), EP300 (8%), and both CREBBP and EP300 (1%). A total of 17 patients were enrolled into stage 1 (the intent-to-treat population); no patients were enrolled in subsequent stages. One partial response was observed (11% [1 of 9 patients; the population that was evaluable for efficacy comprised 9 of the 15 planned patients]); activity was deemed insufficient to progress to stage 2 (null hypothesis: objective response rate of ≤15%). All patients experienced ≥1 adverse event, most commonly nausea (13 of 17 patients; 77%) and fatigue (12 of 17 patients; 71%). The median duration of treatment was 46 days; treatment interruptions (14 of 17 patients; 82%) and dose reductions (5 of 17 patients; 29%) were common. Mocetinostat exposure was lower than anticipated (dose-normalized maximum serum concentration [Cmax ] after TIW dosing of 0.2 ng/mL/mg). CONCLUSIONS: To the authors' knowledge, the current study represents the first clinical trial using genomic-based selection to identify patients with urothelial cancer who are likely to benefit from selective histone deacetylase inhibition. Mocetinostat was associated with significant toxicities that impacted drug exposure and may have contributed to modest clinical activity in these pretreated patients. The efficacy observed was considered insufficient to warrant further investigation of mocetinostat as a single agent in this setting.

Patient-Reported Outcomes and Quality of Life with Sunitinib Versus Placebo for Pancreatic Neuroendocrine Tumors: Results From an International Phase III Trial.

OBJECTIVE: The objective of this analysis was to compare patient-reported outcomes and health-related quality of life (HRQoL) in a pivotal phase III trial of sunitinib versus placebo in patients with progressive, well-differentiated pancreatic neuroendocrine tumors (NCT00428597). PATIENTS AND METHODS: Patients received sunitinib 37.5 mg (n = 86) or placebo (n = 85) on a continuous daily-dosing schedule until disease progression, unacceptable adverse events (AEs), or death. Patients completed the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 at baseline, Day 1 of every 4-week cycle, and end of treatment or withdrawal. Changes ≥10 points on each scale or item were deemed clinically meaningful. RESULTS: Sunitinib had anti-tumor effects and improved progression-free survival (PFS) compared with placebo. The study was terminated early for this reason and because of more serious AEs and deaths with placebo. Baseline HRQoL scores were well balanced between study arms, and were generally maintained over time in both groups. In the first 10 cycles, there were no significant differences between groups in global HRQoL, cognitive, emotional, physical, role, and social functioning domains, or symptom scales, except for worsening diarrhea with sunitinib (p < 0.0001 vs. placebo). Insomnia also worsened with sunitinib (p = 0.0372 vs. placebo), but the difference was not clinically meaningful. CONCLUSION: With the exception of diarrhea (a recognized side effect), sunitinib had no impact on global HRQoL, functional domains, or symptom scales during the progression-free period. Hence, in patients with pancreatic neuroendocrine tumors, sunitinib provided a benefit in PFS without adversely affecting HRQoL.

Sunitinib combined with pemetrexed and carboplatin in patients with advanced solid malignancies--results of a phase I dose-escalation study.

OBJECTIVES: The maximum tolerated dose (MTD) and overall safety of sunitinib plus pemetrexed and carboplatin was determined in patients with advanced solid malignancies. METHODS: In this phase I dose-escalation study, patients received oral sunitinib on a continuous daily dosing (CDD) schedule (37.5 mg/day) or Schedule 2/1 (2 weeks on treatment, 1 week off treatment; 37.5 or 50 mg/day). Pemetrexed (400-500 mg/m(2) IV) and carboplatin (AUC = 5 mg·min/ml IV) were administered q3w. At the MTD for the chosen schedule, a cohort of patients with non-small cell lung cancer (NSCLC) or mesothelioma was further evaluated. RESULTS: Twenty-one patients were enrolled on Schedule 2/1 (expansion cohort included) and 3 patients on the CDD schedule. The MTD on Schedule 2/1 was sunitinib 37.5 mg/day with pemetrexed 500 mg/m(2) and carboplatin AUC = 5 mg·min/ml; MTD on the CDD schedule was not established. Dose-limiting toxicities included grade 3/4 neutropenia, grade 3 thrombocytopenia, and grade 3 hand-foot syndrome. The most common grade 3/4 drug-related non-hematologic adverse events at Schedule 2/1 MTD were fatigue/asthenia and diarrhea (both n = 4). Grade 3/4 hematologic abnormalities included neutropenia (83%) and leukopenia (83%). Pharmacokinetic data revealed no clinically significant drug-drug interactions. Best response at the Schedule 2/1 MTD was stable disease ≥8 weeks in 3/5 evaluable patients (60%). CONCLUSIONS: With this combination, in patients with advanced solid malignancies, sunitinib MTD on Schedule 2/1 was 37.5 mg/day. Sunitinib plus pemetrexed and carboplatin were tolerable at the MTD, although sunitinib dose delays and reductions were often required due to myelosuppression.

Phase II study of sunitinib in Japanese patients with unresectable or metastatic, well-differentiated pancreatic neuroendocrine tumor.

BACKGROUND: Pancreatic neuroendocrine tumors (NETs) are rare but are frequently diagnosed at advanced stages and require systemic therapy. PATIENTS AND METHODS: This multicenter, open-label, phase II study evaluated sunitinib in Japanese patients with well-differentiated pancreatic NET. Patients received sunitinib 37.5 mg/day on a continuous daily dosing (CDD) schedule. The primary endpoint was clinical benefit rate (CBR; percentage of complete responses [CRs] plus partial responses [PRs] plus stable disease [SD] ≥ 24 weeks). Secondary endpoints included objective response rate (ORR), tumor shrinkage, progression-free survival (PFS) probability, safety, pharmacokinetics, and biomarkers. RESULTS: Twelve patients received treatment. The CBR was 75 % (95 % confidence interval [CI], 43-94) and included 6 patients with a PR and 3 with SD. The ORR was 50 % (95 % CI, 21-79). PFS probability was 91 % (95 % CI, 54-99) at 6 months and 71 % (95 % CI, 34-90) at 12 months. Commonly reported treatment-emergent (all-causality), any-grade adverse events included diarrhea (n=10), hand-foot syndrome and hypertension (both n=8), fatigue and headache (both n=7), and neutropenia (n=6). No deaths on study were reported; one death due to disease progression occurred >28 days after end of treatment. Sunitinib on a CDD schedule resulted in sustained drug concentrations without accumulation across cycles. Tumor responses in all 12 patients did not appear to correlate with decreases in chromogranin A levels. CONCLUSIONS: Sunitinib 37.5 mg/day on a CDD schedule demonstrated antitumor activity in Japanese patients with unresectable, well-differentiated pancreatic NET. Commonly reported adverse events were consistent with the known safety profile of sunitinib.

Sunitinib combined with pemetrexed and cisplatin: results of a phase I dose-escalation and pharmacokinetic study in patients with advanced solid malignancies, with an expanded cohort in non-small cell lung cancer and mesothelioma.

PURPOSE: To determine the maximum tolerated dose (MTD), safety and tolerability of sunitinib plus pemetrexed and cisplatin for advanced solid malignancies. METHODS: Using a 3 + 3 dose-escalation design, patients received oral sunitinib (37.5 or 50 mg) qd on a continuous daily dosing (CDD) schedule or Schedule 2/1 (2 weeks on, 1 week off treatment) plus pemetrexed (400 or 500 mg/m(2) IV) and cisplatin (75 mg/m(2) IV) q3w up to 6 cycles. RESULTS: Sunitinib 37.5 mg/pemetrexed 400 mg/m(2)/cisplatin 75 mg/m(2) CDD (n = 5) was not tolerated. Lower doses on this schedule were not explored. The Schedule 2/1 MTD (n = 15) was sunitinib 37.5 mg/pemetrexed 500 mg/m(2)/cisplatin 75 mg/m(2), based on one dose-limiting toxicity (myocardial infarction) out of six patients. The MTD was further studied in an expansion cohort of 10 non-small cell lung cancer (NSCLC) patients and one mesothelioma patient. There were no clinically significant drug-drug interactions. Cumulative myelosuppression was problematic: the median relative dose intensity (% actual/intended) across all cycles was 61 % for sunitinib, 78 % for pemetrexed, and 74 % for cisplatin. Four of eight NSCLC patients in the dose-escalation and expansion cohorts at the Schedule 2/1 MTD who were evaluable for efficacy had stable disease ≥ 8 weeks, and the one patient with mesothelioma had a partial response. CONCLUSIONS: In patients with advanced solid malignancies, sunitinib was not tolerated at 37.5 mg CDD with standard pemetrexed and cisplatin doses. Dose reductions were often needed due to cumulative myelosuppression following cycle 1. The MTD showed modest antitumor activity.

Sunitinib plus erlotinib for the treatment of advanced/metastatic non-small-cell lung cancer: a lead-in study.

BACKGROUND: This randomized, double-blind, multicenter study evaluated sunitinib plus erlotinib versus placebo plus erlotinib. Subjects with advanced non-small-cell lung cancer had received prior treatment with a platinum-based regimen. Here, we report safety, pharmacokinetics, and antitumor activity of the combination of sunitinib and erlotinib. METHODS: Lead-in subjects in this phase II study received sunitinib 37.5 mg/d and erlotinib 150 mg/d. Safety, including dose-limiting toxicities (DLTs, cohort 1 only), pharmacokinetic profiles, and antitumor activity were investigated (cohorts 1 and 2). RESULTS: Thirty patients were evaluated. The combination of sunitinib and erlotinib was tolerable. Diarrhea (76.9%), fatigue (61.5%), and decreased appetite (53.8%) were the most frequent adverse events in cohort 1; and diarrhea (52.9%) and rash (41.2%) were the most frequent adverse events in cohort 2. DLTs were observed (fatigue, n = 2 and paronychial inflammation, n = 1) in three of 13 patients evaluated for DLTs. Geometric mean ratios for the maximum plasma concentration (Cmax) and area under plasma concentration-time profile from time 0 to 24 hours of erlotinib with and without sunitinib were 1.05 and 1.03, respectively. Corresponding values for sunitinib with and without erlotinib were 0.62 and 0.62 for sunitinib, 2.13 and 2.07 for SU12662; and 0.81 and 0.79 for total drug. Three patients experienced partial response as per response evaluation criteria in solid tumor. CONCLUSION: A dosage of sunitinib 37.5 mg/d concurrently with erlotinib 150 mg/d was tolerable and established the recommended combinatorial dose in subjects with platinum-refractory non-small-cell lung cancer. Coadministration of sunitinib with erlotinib does not affect the pharmacokinetics of erlotinib, but may result in decreased exposure to sunitinib.

Sunitinib plus erlotinib versus placebo plus erlotinib in patients with previously treated advanced non-small-cell lung cancer: a phase III trial.

PURPOSE: Sunitinib plus erlotinib may enhance antitumor activity compared with either agent alone in non-small-cell lung cancer (NSCLC), based on the importance of the signaling pathways involved in tumor growth, angiogenesis, and metastasis. This phase III trial investigated overall survival (OS) for sunitinib plus erlotinib versus placebo plus erlotinib in patients with refractory NSCLC. PATIENTS AND METHODS: Patients previously treated with one to two chemotherapy regimens (including one platinum-based regimen) for recurrent NSCLC, and for whom erlotinib was indicated, were randomly assigned (1:1) to sunitinib 37.5 mg/d plus erlotinib 150 mg/d or to placebo plus erlotinib 150 mg/d, stratified by prior bevacizumab use, smoking history, and epidermal growth factor receptor expression. The primary end point was OS. Key secondary end points included progression-free survival (PFS), objective response rate (ORR), and safety. RESULTS: In all, 960 patients were randomly assigned, and baseline characteristics were balanced. Median OS was 9.0 months for sunitinib plus erlotinib versus 8.5 months for erlotinib alone (hazard ratio [HR], 0.922; 95% CI, 0.797 to 1.067; one-sided stratified log-rank P = .1388). Median PFS was 3.6 months versus 2.0 months (HR, 0.807; 95% CI, 0.695 to 0.937; one-sided stratified log-rank P = .0023), and ORR was 10.6% versus 6.9% (two-sided stratified log-rank P = .0471), respectively. Treatment-related toxicities of grade 3 or higher, including rash/dermatitis, diarrhea, and asthenia/fatigue were more frequent in the sunitinib plus erlotinib arm. CONCLUSION: In patients with refractory NSCLC, sunitinib plus erlotinib did not improve OS compared with erlotinib alone, but the combination was associated with a statistically significantly longer PFS and greater ORR. The incidence of grade 3 or higher toxicities was greater with combination therapy.

Phase II study of sunitinib as maintenance therapy in patients with locally advanced or metastatic non-small cell lung cancer.

This open-label, phase II study evaluated the antitumor activity and safety of sunitinib monotherapy as maintenance treatment following first-line chemotherapy in patients with locally advanced or metastatic non-small cell lung cancer (NSCLC). Following treatment with standard doublet chemotherapy (paclitaxel and carboplatin), patients received oral sunitinib (starting dose 50mg/day) in 6-week cycles (Schedule 4/2: 4 weeks on treatment, 2 weeks off treatment) until disease progression, unacceptable toxicity or withdrawal of consent. The primary endpoint was probability of survival at 1 year ≥55%. Of 84 patients who received first-line chemotherapy, 66 (79%) received sunitinib maintenance therapy (median sunitinib cycles started: 2 [range 1-20]). Probability of survival at 1 year was 40.5% (95% confidence interval [CI]: 29.8, 51.0). Median overall survival was 10.4 months (95% CI: 8.0, 12.2). The objective response rate was 27.4% (95% CI: 18.2, 38.2). The most frequently reported all-causality adverse events of any grade during sunitinib maintenance therapy were fatigue/asthenia (55%), diarrhea (36%), and nausea (32%). These data suggest that maintenance therapy may have value in NSCLC, although the primary endpoint of the study was not met.

Phase II study of sunitinib in patients with non-small cell lung cancer and irradiated brain metastases.

INTRODUCTION: Brain metastases frequently cause significant morbidity in patients with non-small cell lung cancer (NSCLC). Sunitinib is a multitargeted inhibitor of tyrosine kinase receptors, including vascular endothelial growth factor receptors and platelet-derived growth factor receptors, which has single-agent antitumor activity in refractory NSCLC. This phase II study evaluated the antitumor activity and safety of sunitinib in patients with pretreated NSCLC and irradiated brain metastases. METHODS: Patients received sunitinib 37.5 mg on a continuous daily dosing schedule. The primary end point was progression-free survival. Secondary end points included overall survival, patient-reported outcomes, and safety, including risk of intracranial hemorrhage (ICH) associated with focal neurological deficit. RESULTS: Sixty-four patients received sunitinib (median age 61 years), most (83%) had received prior systemic therapy, 63% had adenocarcinoma, and 19% had squamous cell carcinoma; most (55%) were never-smokers. Median progression-free survival was 9.4 weeks (90% confidence interval [CI]: 7.5-13.1), and median overall survival was 25.1 weeks (95% CI: 13.4-35.5). The most common treatment-emergent (all-causality) nonhematologic toxicities (any grade) were fatigue (38%) and decreased appetite and constipation (both 25%). The most common grade 3/4 nonhematologic toxicities were dyspnea (9%) and fatigue (8%). Lymphopenia (20%) and neutropenia (13%) were the most common grade 3/4 hematologic abnormalities. Serious neurologic adverse events occurred in six patients (9%), and none were treatment-related. No cases of ICH were reported. CONCLUSIONS: Sunitinib administration on a continuous daily dosing schedule in patients with NSCLC and brain metastases was safe and manageable, with no increased risk of ICH.

Sunitinib in combination with paclitaxel plus carboplatin in patients with advanced solid tumors: phase I study results.

PURPOSE: To evaluate the maximum tolerated dose (MTD), safety, and antitumor activity of sunitinib combined with paclitaxel and carboplatin. METHODS: Successive cohorts of patients with advanced solid tumors received oral sunitinib (25, 37.5, or 50 mg) for 2 consecutive weeks of a 3-week cycle (Schedule 2/1) or as a continuous daily dose for 3-week cycles (CDD schedule) in combination with paclitaxel (175-200 mg/m(2)) plus carboplatin (AUC 6 mg min/ml) on day one of each of 4 cycles. Dose-limiting toxicities (DLTs) and adverse events (AEs) were evaluated to determine the MTD. Efficacy parameters were analyzed in patients with measurable disease. RESULTS: Forty-three patients were enrolled (n = 25 Schedule 2/1; n = 18 CDD schedule). Across all doses, 6 DLTs were observed [grade 4 papilledema, grade 5 GI hemorrhage, grade 3 neutropenic infection, and grade 4 thrombocytopenia (n = 3)]. The MTD for Schedule 2/1 was sunitinib 25 mg plus paclitaxel 175 mg/m(2) and carboplatin AUC 6 mg min/ml. The MTD was not determined for the CDD schedule. Treatment-related AEs included neutropenia (77%), thrombocytopenia (56%), and fatigue (47%). Of 38 evaluable patients, 4 (11%) had partial responses and 12 (32%) had stable disease. PK data indicated an increase in maximum and total plasma exposures to sunitinib and its active metabolite when given with paclitaxel and carboplatin compared with sunitinib monotherapy. CONCLUSIONS: Myelosuppression resulting in prolonged dose delays and frequent interruptions was observed, suggesting that this treatment combination is not feasible in the general cancer population.

Multicenter, phase II trial of sunitinib in previously treated, advanced non-small-cell lung cancer.

PURPOSE: Aberrant vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) signaling have been shown to play a role in non-small-cell lung cancer (NSCLC) pathogenesis and are associated with decreased survival. We evaluated the clinical activity and tolerability of sunitinib malate (SU11248), an oral, multitargeted tyrosine kinase inhibitor that blocks the activity of receptors for VEGF and PDGF, as well as related tyrosine kinases in patients with previously treated, advanced NSCLC. PATIENTS AND METHODS: Patients with stage IIIB or IV NSCLC for whom platinum-based chemotherapy had failed received 50 mg/d of sunitinib for 4 weeks followed by 2 weeks of no treatment in 6-week treatment cycles. The primary end point was objective response rate (ORR); secondary end points included progression-free survival, overall survival, and safety. RESULTS: Of the 63 patients treated with sunitinib, seven patients had confirmed partial responses, yielding an ORR of 11.1% (95% CI, 4.6% to 21.6%). An additional 18 patients (28.6%) experienced stable disease of at least 8 weeks in duration. Median progression-free survival was 12.0 weeks (95% CI, 10.0 to 16.1 weeks), and median overall survival was 23.4 weeks (95% CI, 17.0 to 28.3 weeks). Therapy was generally well tolerated. CONCLUSION: Sunitinib has promising single-agent activity in patients with recurrent NSCLC, with an ORR similar to that of currently approved agents and an acceptable safety profile. Further evaluation in combination with other targeted agents and chemotherapy in patients with NSCLC is warranted.

Phase II trial of sunitinib in patients with metastatic colorectal cancer after failure of standard therapy.

PURPOSE: Sunitinib is an oral, multitargeted receptor tyrosine kinase inhibitor of the vascular endothelial growth factor receptor and multiple other growth factor receptors. We assessed the safety and efficacy of sunitinib in patients with metastatic colorectal cancer after failure of standard therapy. PATIENTS AND METHODS: Eighty-four patients were enrolled onto this two-stage phase II trial and were stratified by whether they had received prior bevacizumab (n = 43) or not (n = 41). Treatment comprised sunitinib 50 mg orally daily for 4 weeks, followed by 2 weeks off treatment, in repeated 6-week cycles. RESULTS: By Response Evaluation Criteria in Solid Tumors criteria, one patient, who was in the prior bevacizumab cohort, achieved a partial response, and 13 patients (two in the prior bevacizumab cohort and 11 in the no prior bevacizumab cohort) achieved stable disease lasting > or = 22 weeks. Median time to progression in the prior bevacizumab and bevacizumab-naïve cohorts was 2.2 months (95% CI, 1.9 to 2.3 months) and 2.5 months (95% CI, 2.3 to 3.1 months), respectively, whereas median overall survival time was 7.1 months (95% CI, 4.9 to 10.6 months) and 10.2 months (95% CI, 8.2 to 15.3 months), respectively. The most common adverse events were fatigue, diarrhea, nausea, vomiting, and anorexia. Twenty-six patients (32%) required dose reduction to 37.5 mg/d, and one patient required dose reduction to 25 mg/d. CONCLUSION: Sunitinib did not demonstrate a meaningful single-agent objective response rate in colorectal cancer refractory to standard chemotherapy. However, the mechanisms of action and acceptable safety profile of sunitinib warrant further study in combination with standard regimens for metastatic colorectal cancer.

Therapy-induced malignant neoplasms in Nf1 mutant mice.

Therapy-induced cancers are a severe complication of genotoxic therapies. We used heterozygous Nf1 mutant mice as a sensitized genetic background to investigate tumor induction by radiation (RAD) and cyclophosphamide (CY). Mutagen-exposed Nf1(+/-) mice developed secondary cancers that are common in humans, including myeloid malignancies, sarcomas, and breast cancers. RAD cooperated strongly with heterozygous Nf1 inactivation in tumorigenesis. Most of the solid tumors showed loss of the wild-type Nf1 allele but retained two Trp53 alleles. Comparative genomic hybridization demonstrated distinct patterns of copy number aberrations in sarcomas and breast cancers from Nf1 mutant mice, and tumor cell lines showed deregulated Ras signaling. Nf1(+/-) mice provide a tractable model for investigating the pathogenesis of common mutagen-induced cancers and for testing preventive strategies.

Comparative pathology of nerve sheath tumors in mouse models and humans.

Despite the progress made in our understanding of the biology of neurofibromatosis (NF), the long-term clinical outcome for affected patients has not changed significantly in the past decades, and both NF1 and NF2 are still associated with a significant morbidity and a decreased life span. A number of NF1 and NF2 murine models have been generated to aid in the study of NF tumor biology and in the development of targeted therapies for NF patients. A single, universal pathological classification of the lesions generated in these murine models is essential for the validation of the models, for their analysis and comparison with other models, and for their future effective use in preclinical treatment trials. For the formulation of a pathological classification of these lesions, the WHO classification of human tumors was used as a reference. However, it was not adopted for the classification of the GEM lesions because of some important differences between the human and murine lesions. A novel classification scheme for peripheral nerve sheath tumors in murine models was therefore devised.