Patterns of care and outcomes for gastric and gastro-oesophageal junction cancer in an Australian population

INTEGRATE IIa Phase III Study: Regorafenib for Refractory Advanced Gastric Cancer

PURPOSE

Treatment options for refractory advanced gastric and esophagogastric junction cancer (AGOC) are limited. Regorafenib, an oral multikinase inhibitor, prolonged progression-free survival (PFS) versus placebo in the INTEGRATE I phase II trial. INTEGRATE IIa was designed to examine whether regorafenib improved overall survival (OS).

METHODS

A double-blind placebo-controlled phase III trial compared regorafenib and best supportive care (BSC) versus placebo and BSC for participants with confirmed evaluable metastatic/advanced AGOC who failed ≥two prior therapies on a 2:1 random assignment, stratified by tumor location, geographic region (Asia v rest of world), and prior vascular endothelial growth factor inhibitors. The primary end point was OS. Treatment efficacy on OS was first tested in the pooled INTEGRATE I + INTEGRATE IIa cohort and, if significant, then in the INTEGRATE IIa cohort. Secondary end points were PFS, objective response rate, safety, and quality of life (QoL).

RESULTS

INTEGRATE IIa enrolled 251 participants: 157 from Asia and 94 from rest of world and 169 received regorafenib and 82 received placebo. No significant heterogeneity was observed between INTEGRATE I and INTEGRATE IIa studies on OS. Pooled OS analysis hazard ratio (HR) was 0.70 (95% CI, 0.56 to 0.87; P = .001; 361 events). INTEGRATE IIa alone OS HR was 0.68 (95% CI, 0.52 to 0.90; P = .006; 238 events), the median OS was 4.5 months versus 4.0 months, and 12-month survival rates were 19% and 6%, for regorafenib versus placebo, respectively. After a preplanned adjustment for multiplicity, there were no statistically significant differences across regions or other prespecified subgroups. Regorafenib improved PFS (HR, 0.53 [95% CI, 0.40 to 0.70]; P < .0001) and delayed deterioration in global QoL (HR, 0.68 [95% CI, 0.52 to 0.89]; P = .0043). The toxicity profile was consistent with that of previous reports.

CONCLUSION

Regorafenib improves survival compared with placebo in refractory AGOC.

INTEGRATE II: randomised phase III controlled trials of regorafenib containing regimens versus standard of care in refractory Advanced Gastro-Oesophageal Cancer (AGOC): a study by the Australasian Gastro-Intestinal Trials Group (AGITG)

BACKGROUND

Advanced gastro-oesophageal cancer (AGOC) carries a poor prognosis. No standard of care treatment options are available after first and second-line therapies. Regorafenib is an oral multi-targeted tyrosine kinase inhibitor targeting angiogenic, stromal, and oncogenic receptor tyrosine kinases. Regorafenib 160 mg daily prolonged progression free survival compared to placebo (INTEGRATE, phase 2). Regorafenib 80 mg daily in combination with nivolumab 3 mg/kg showed promising objective response rates (REGONIVO).

METHODS/DESIGN

INTEGRATE II (INTEGRATE IIa and IIb) platform comprises two international phase III randomised controlled trials (RCT) with 2:1 randomisation in favor of experimental intervention. INTEGRATE IIa (double-blind) compares regorafenib 160 mg daily on days 1 to 21 of each 28-day cycle to placebo. INTEGRATE IIb (open label) compares REGONIVO, regorafenib 90 mg days 1 to 21 in combination with intravenous nivolumab 240 mg days 1 and 15 each 28-day cycle with investigator's choice of chemotherapy (control). Treatment continues until disease progression or intolerable adverse events as per protocol. Eligible participants include adults with AGOC who have failed two or more lines of treatment. Stratification is by location of tumour (INTEGRATE IIa only), geographic region, prior VEGF inhibitor and prior immunotherapy use (INTEGRATE IIb only). Primary endpoint is overall survival. Secondary endpoints are progression free survival, objective response rate, quality of life, and safety. Tertiary/correlative objectives include biomarker and pharmacokinetic evaluation.

DISCUSSION

INTEGRATE II provides a platform to evaluate the clinical utility of regorafenib alone, as well as regorafenib in combination with nivolumab in treatment of participants with refractory AGOC.

TRIAL REGISTRATION

INTEGRATE IIa prospectively registered 1 April 2016 Australia New Zealand Clinical Trial Registry: ACTRN12616000420448 (ClinicalTrials.gov NCT02773524). INTEGRATE IIb prospectively registered 10 May 2021 ClinicalTrials.gov: NCT04879368.

Neoadjuvant Chemo-Radiation Using IGRT in Patients with Locally Advanced Gastric Cancer

The goal of this study was to see how effective and safe neoadjuvant chemoradiation with image-guided IMRT was in patients with locally advanced resectable gastric cancer. Between January 2013 and June 2019, patients with locally advanced (cT3/cT4 or N+) gastric cancer treated with neoadjuvant chemoradiotherapy at PUMCH (Peking Union Medical College Hospital) were retrospectively studied. Using concurrent chemotherapy (Capecitabine alone or XELOX*2 cycles), radiotherapy (IMRT (intensity-modulated radiation therapy) 45 Gy, 25#, 5 weeks) was delivered with IGRT (image-guided radiotherapy) before the start of each weeks therapy to ensure accuracy and repeatability. A total of 95 patients were enrolled in the study, 93 (97.9%) stage cT3/T4 and 85 (89.5%) stage N+. Of these, 85 patients (89.5%) had a tumor located in the upper 1/3 of the stomach, and 93/95 patients (97.9%) completed neoadjuvant chemoradiation, with 80 patients (84.2%) undergoing stomach resection (58 D2 and 22 D1 gastrostomies). Pathology downstaging was found in 68 patients (85.0%), with 66 patients (82.5%) receiving T downstaging and 56 patients (70.0%) receiving N downstaging. There were 11 individuals (13.8%) who had a pathological complete response (PCR). The average period of follow-up was 44.7 months (19-96 months). The 5-year OS (overall survival), LRFS (local recurrence-free survival), and DMFS (distant metastasis free survival) rates of patients were 47.0% (95% CI: 38.6-55.4), 86.55% (95% CI: 79.1-93.99) and 60.71% (95% CI: 51.49-69.93%), respectively. Thirteen (13.7%) patients had grade 3-4 leukopenia, anemia, and thrombocytopenia, while 9 (9.5%) patients had grade 3-4 anemia, and 5 (5.3%) patients had grade 3-4 thrombocytopenia. PCR was found to be a significant predictive factor for OS in multivariate analysis (HR = 11.211, 95% CI: 1.500-83.813, p = 0.024). The method of using IGRT image-guided IMRT (45 Gy, 25 fractions, 5 weeks) combined with concurrent chemotherapy in patients with locally advanced resectable gastric cancer was equally effective when compared to the clinical efficacy of neoadjuvant chemoradiotherapy, with clinical outcomes achieving equal efficacy, with similar PCR rates and high rates of OS, LRFS, and DMFS, as well as good tolerances of concurrent chemoradiotherapy with acceptable side effects.