ARTIA-Bladder: Daily Online Adaptive Short-Course Radiation Therapy (RT) and Concurrent Chemotherapy for Muscle-Invasive Bladder Cancer (MIBC): A Prospective Trial of an Individualized Approach for Reducing Bowel and Bladder Toxicity

PURPOSE/OBJECTIVE(S)

Concurrent chemo-radiotherapy is commonly prescribed for muscle-invasive bladder cancer (MIBC). Post hoc analysis of two large, randomized trials found that hypofractionation improves loco-regional control (LRC) vs. standard fractionation in this population. A challenge in traditional image-guided radiotherapy of the bladder is that daily changes in bladder position and size requires large margins to ensure target coverage. This makes it difficult to spare uninvolved bladder from high-dose treatment, increases the risk of bowel toxicity, and results in historical rates of acute G3+ toxicity exceeding 20-30%. Daily online adaptive RT (ART) may enable reduced, personalized margins that maintain target coverage while reducing dose to OARs. This prospective clinical trial will test whether: 1) participants undergoing ART for MIBC have a lower rate of acute G3+ GI/GU toxicity compared with the 31% historical control rate (Stage III BC2001 trial), and 2) 2-year LRC with ART will be non-inferior to historical controls (75%).

MATERIALS/METHODS

This multi-national trial will enroll 165 adult subjects with stage cT2-T4aN0M0 urothelial MIBC. Subjects will have undergone an attempt at maximal transurethral resection of bladder tumor. Patients with clinically involved nodes or G2+ GI or G3+ GU symptoms/conditions at baseline are ineligible. Concurrent with chemotherapy, participants will receive (at the discretion of the investigator) either 55 Gy in 20 fx to whole-bladder or 46 Gy in 20 fx to whole-bladder plus simultaneous in-field boost of 55 Gy in 20 fx to tumor bed. A personalized ITV will be derived for each subject based on bladder expansion, as assessed on two CT simulations separated by 30 min. Daily ART will be attempted for all subjects. The primary endpoint is acute G3+ GI/GU toxicity. Secondary endpoints are LRC; quality of life (EORTC QLQ-BLM30, EPIC 26 bowel and urinary); global function (EQ-5D-5L ); 2-year disease-free, bladder intact event-free, and overall survival; 2-year bladder cancer-specific mortality; NTCP model of acute GI toxicity for hypofractionated bladder RT; workflow feasibility of ART; improved target coverage ± reduced dose to critical OARs vs. non-ART dosimetry; acute G3+ GI/GU toxicity rate in subjects with ≥75% of their treatments as ART; and acute G3+ GI/GU toxicity in the cohort treated with partial bladder boost. Exploratory translational and correlative endpoints will also be examined.

RESULTS

This trial opened to enrollment on Feb 2, 2023; the study duration is expected to be 4-5 years.

CONCLUSION

This prospective clinical trial will provide robust clinical data to inform healthcare providers' decisions on the use of daily online ART and hypofractionation as a bladder preservation strategy for this population.

Relationship among circulating tumor cells, CEA and overall survival in patients with metastatic colorectal cancer

BACKGROUND

We previously reported results of a prospective trial evaluating the significance of circulating tumor cells (CTCs) in patients with metastatic colorectal cancer (mCRC). This secondary analysis assessed the relationship of the CTC number with carcinoembryonic antigen (CEA) and overall survival.

PATIENTS AND METHODS

Patients with mCRC had CTCs measured at baseline and specific time points after the initiation of new therapy. Patients with a baseline CEA value ≥ 10 ng/ml and CEA measurements within ± 30 days of the CTC collection were included.

RESULTS

We included 217 patients with mCRC who had a CEA value of ≥ 10 ng/ml. Increased baseline CEA was associated with shorter survival (15.8 versus 20.7 months, P = 0.012). Among all patients with a baseline CEA value of ≥ 25 ng/ml, patients with low baseline CTCs (<3, n = 99) had longer survival than those with high CTCs (≥ 3, n = 58; 20.8 versus 11.7 months, P = 0.001). CTCs added prognostic information at the 3-5- and 6-12-week time points regardless of CEA. In a multivariate analysis, CTCs at baseline but not CEA independently predicted survival and both CTCs and CEA independently predicted survival at 6-12 weeks.

CONCLUSIONS

This study demonstrates that both CEA and CTCs contribute prognostic information for patients with mCRC.

A USA registry of gastrointestinal stromal tumor patients: changes in practice over time and differences between community and academic practices

BACKGROUND

The objective of the study was to describe patterns of care of patients with gastrointestinal stromal tumors (GISTs) in the United States in the tyrosine kinase inhibitor (TKI) era.

PATIENTS AND METHODS

From November 2004 through March 2009, data were collected regarding demographics, diagnostic history, treatment, relapse, and survival of 882 patients with GIST from 122 community and academic medical practices.

RESULTS

The most common first-line treatment for the 719 patients presenting with localized GIST was surgery (87%). Use of adjuvant imatinib increased after June 2007; 47% of patients enrolled in the registry considered by the investigator to be at high risk for recurrence received adjuvant imatinib after June 2007 versus 18% before. Overall, 56% of patients received imatinib and 11% received sunitinib. The utilization of targeted therapy increased over time (45% and 0.4% of patients received imatinib and sunitinib, respectively, in 2006 versus 56% and 11%, respectively, in 2009).

CONCLUSIONS

These are the first GIST registry data from the TKI era. The use of targeted therapy for GIST has increased in accordance with updated treatment guidelines. Diagnosis of GIST has evolved with increased use of KIT testing. The duration of targeted therapy in the adjuvant therapy setting is similar in community and academic practices.

MC0553: A phase II safety and efficacy study with the VEGF receptor tyrosine kinase inhibitor pazopanib in patients with metastatic urothelial cancer

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Background: Vascular endothelial growth factor (VEGF) and platelet derived growth factor (PDGF) are produced by bladder cancer cell lines in vitro and expressed in human tumor tissues. Preclinical studies have also shown that bladder cancer cell lines express VEGF receptor 1 and 2 on their surface membrane. Pazopanib is a vascular endothelial receptor tyrosine kinase inhibitor with anti-angiogenesis and antitumor activity in several preclinical models. A two-stage phase II study was conducted to assess the activity and toxicity profile of pazopanib administered to patients with metastatic, urothelial carcinoma.

Methods: Patients with one prior systemic therapy for recurrent, metastatic urothelial carcinoma were eligible. Patients received pazopanib at a dose of 800 mg orally daily for 4 week cycle.

Results: Nineteen patients were enrolled. Median age was 66 years, with > 89% of patients presenting poorly differentiated bladder cancer. Adverse event data is available on 18 patients. No grade 4 or 5 events have been experienced. Nine patients have experienced 11 grade 3 adverse events of which 7 were deemed at least possibly related to treatment. Most common toxicities were anemia, thrombocytopenia, leucopenia and fatigue. For stage 1, none of the first 16 evaluable patients were deemed success (CR or PR) by the RECIST criteria during the first four 4-week cycles of treatment. Median progression- free survival was 1.9 months. This met the futility stopping rule of interim analysis, and therefore, the trial was recommended to be permanently closed. Correlative studies including measurement of VEGF levels in archived tissues and blood are pending.

Conclusions: Pazopanib did not show activity in urothelial carcinoma patients. The role of anti-VEGF therapies in urothelial carcinoma may need further evaluation in rational combination strategies.

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Phase I study of everolimus (RAD001) with irinotecan (Iri) and cetuximab (C) in second-line metastatic colorectal cancer: Hoosier Oncology Group GI05-102

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Background: Preclinically, mTOR and EGFR inhibitors are synergistic. We hypothesize that the mTOR inhibitor RAD001 would enhance efficacy and prevent resistance when added to an anti-EGFR agent. The purpose of the phase I portion of this study was to determine the safety and maximum tolerated dose (MTD) of daily RAD001 combined with weekly Iri and C in mCRC.

Methods: Pts who failed first-line therapy, including an Iri-regimen, were treated with Iri 125 mg/m2 weekly x 2 every 3 weeks, C 400 mg/m2 loading dose, then 250 mg/m2 weekly, and escalating doses of RAD001 orally: 5 mg qod, 5 mg qd and 10 mg qd during 21-day cycles, with a “3+3” design. The study was amended after the first 9 pts enrolled, to include stopping rules for excessive toxicity beyond what was expected for diarrhea, nausea/vomiting and febrile neutropenia due to Iri, and skin rash due to C. Enrollment excluded pts with UGT1A1*28, but allowed KRAS mutated mCRC. RAD001 PK was done on C2D1, and archival tumors were analyzed for pharmacodynamic markers.

Results: 28 pts were enrolled, median age 61 y (25-77), 15 male, ECOG PS 0/1 (19/9). Reasons for treatment discontinuation were: PD (7), adverse events (AEs) (6), pt withdrawal, symptomatic deterioration and non-compliance (1 each). Prior to study's amendment* (n=9), 3 pts were not evaluable for DLT due to: Iri intolerance after one dose (1), non-compliance (1) and gr 3 C infusion reaction (1). DLTs and number of cycles are listed in Table. Following protocol amendment, 2 pts had DLT in cohort 3 (gr 3 mucositis), thus the MTD was 5 mg RAD001. The most common grade 3/4 AEs were: diarrhea (10), neutropenia (5), fatigue (4), acne-rash (4), mucositis (2), nausea (2), vomiting (1). Among 19 pts evaluable for response, there were 1 CR, 2 PR, (RR 16%), 9 SD (47%), 7 PD (37%). PK and pharmacodynamic data is ongoing.

Conclusions: The MTD of RAD001 of 5 mg QD with Iri/C weekly is safe and clinically active. A randomized phase II study is near starting accrual.

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