Regorafenib in Combination with First-Line Chemotherapy for Metastatic Esophagogastric Cancer.

BACKGROUND: Angiogenesis is critical to gastroesophageal adenocarcinoma growth and metastasis. Regorafenib is a multikinase inhibitor targeting angiogenic and stromal receptor tyrosine kinases. We evaluated whether regorafenib augments the antitumor effect of first-line chemotherapy in metastatic esophagogastric cancer. MATERIALS AND METHODS: Patients with previously untreated metastatic gastroesophageal adenocarcinoma received 5-fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) every 14 days and regorafenib 160 mg daily on days 4 to 10 of each 14-day cycle. The primary endpoint was 6-month progression-free survival (PFS). To identify predictive biomarkers of outcome, we examined correlations between genomic characteristics of sequenced pretreatment tumors and PFS. RESULTS: Between August 2013 and November 2014, 36 patients with metastatic esophagogastric cancer were accrued to this single-center phase II study (NCT01913639). The most common grade 3-4 treatment-related adverse events were neutropenia (36%), leucopenia (11%) and hypertension (8%). The 6-month PFS was 53% (95% confidence interval [CI], 38%-71%), the objective response rate was 54% (95% CI, 37%-70%), and the disease control rate was 77% (95% CI, 67%-94%). Next-generation sequencing did not identify any genomic alterations significantly correlated with response, and there was no association between homologous recombination deficiency and PFS with platinum-based chemotherapy. CONCLUSION: Regorafenib (one week on-one week off schedule) is well tolerated in combination with first-line FOLFOX but does not improve 6-month PFS relative to historical control. IMPLICATIONS FOR PRACTICE: Prognosis for metastatic esophagogastric cancer remains poor despite modern systemic therapy regimens. This phase II trial indicates that the combination of regorafenib and FOLFOX is well tolerated but does not add to the efficacy of first-line chemotherapy in metastatic esophagogastric cancer. Notably, recently reported data suggest potential synergy between regorafenib and the PD-1 inhibitor nivolumab. As this study demonstrates that regorafenib plus FOLFOX is safe, and combined chemotherapy and immunotherapy show favorable toxicity profiles, future studies combining immunotherapy with regorafenib and chemotherapy may be feasible.

Clinical Importance of Clonal Hematopoiesis in Metastatic Gastrointestinal Tract Cancers.

Importance: Clonal hematopoiesis (CH) has been associated with development of atherosclerosis and leukemia and worse survival among patients with cancer; however, the association with cancer therapy efficacy, in particular immune checkpoint blockade (ICB), and toxicity has not yet been established. Given the widespread use of ICB and the critical role hematopoietic stem cell-derived lymphocytes play in mediating antitumor responses, CH may be associated with therapeutic efficacy and hematologic toxicity. Objective: To determine the association between CH and outcomes, hematologic toxicity, and therapeutic efficacy in patients with metastatic gastrointestinal tract cancers being treated with systemic therapy, both in the first-line metastatic treatment setting and in ICB. Design, Setting, and Participants: This retrospective cohort study included 633 patients with stage IV colorectal (CRC) and esophagogastric (EGC) cancer who were treated with first-line chemotherapy and/or ICB at Memorial Sloan Kettering Cancer Center. Patients underwent matched tumor and peripheral blood DNA sequencing using the Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets next-generation sequencing assay between January 1, 2006, and December 31, 2020. Exposures: Clonal hematopoiesis-related genetic alterations were identified by next-generation sequencing of patients' tumor and normal blood buffy coat samples, with a subset of these CH alterations annotated as likely putative drivers (CH-PD) based upon previously established criteria. Main Outcomes and Measures: Patients with CH and CH-PD in peripheral blood samples were identified, and these findings were correlated with survival outcomes (progression-free survival [PFS] and overall survival [OS]) during first-line chemotherapy and ICB, as well as baseline white blood cell levels and the need for granulocyte colony-stimulating factor (G-CSF) support. Results: Among the 633 patients included in the study (390 men [61.6%]; median age, 58 [IQR, 48-66] years), the median age was 52 (IQR, 45-63) years in the CRC group and 61 (IQR, 53-69) years in the EGC group. In the CRC group, 161 of 301 patients (53.5%) were men, compared with 229 of 332 patients (69.0%) in the EGC group. Overall, 62 patients (9.8%) were Asian, 45 (7.1%) were Black or African American, 482 (76.1%) were White, and 44 (7.0%) were of unknown race or ethnicity. Presence of CH was identified in 115 patients with EGC (34.6%) and 83 with CRC (27.6%), with approximately half of these patients harboring CH-PD (CRC group, 44 of 83 [53.0%]; EGC group, 55 of 115 [47.8%]). Patients with EGC and CH-PD exhibited a significantly worse median OS of 16.0 (95% CI, 11.6-22.3) months compared with 21.6 (95% CI, 19.6-24.3) months for those without CH-PD (P = .01). For patients with CRC and EGC, CH and CH-PD were not associated with PFS differences in patients undergoing ICB or first-line chemotherapy. Neither CH nor CH-PD were correlated with baseline leukocyte levels or increased need for G-CSF support. Conclusions and Relevance: These findings suggest CH and CH-PD are not directly associated with the treatment course of patients with metastatic gastrointestinal tract cancer receiving cancer-directed therapy.

Phase I/Ib study of crenolanib with ramucirumab and paclitaxel as second-line therapy for advanced esophagogastric adenocarcinoma.

PURPOSE: Paclitaxel plus ramucirumab is a standard second-line regimen for patients with advanced gastric adenocarcinoma, but clinical benefit remains modest. One potential resistance mechanism to VEGFR2 inhibition is activation of the PDGF/PDGFR pathway, which can be blocked by the selective inhibitor crenolanib. Therefore, we performed a phase I/Ib study of crenolanib in combination with paclitaxel/ramucirumab. METHODS: Patients with metastatic esophagogastric adenocarcinoma refractory to first-line therapy received escalating doses of crenolanib [60 mg twice daily (BID) to 100 mg three times daily (TID)] in combination with paclitaxel 80 mg/m2 intravenously on days 1, 8 and 15 and ramucirumab 8 mg/kg intravenously on days 1 and 15 of a 28-day cycle. The primary objective was to determine the maximally tolerated dose (MTD) of crenolanib. Additional patients were enrolled in the dose expansion cohort to assess 6-month progression-free survival (PFS) at the MTD. RESULTS: We enrolled 19 patients in the dose escalation phase and 8 patients in the dose expansion phase at the MTD of crenolanib 100 mg BID. Common grade 3/4 treatment-emergent adverse events included leukopenia (19%), anemia (11%) and neutropenia (11%). In the 14 patients treated at the MTD, 6-month PFS was 43% [95% confidence interval (CI) 23-78%] and the objective response rate (ORR) was 42% (95% CI 15-72%). The trial was terminated early due to withdrawal of crenolanib by the sponsor. CONCLUSIONS: The addition of crenolanib to paclitaxel/ramucirumab is safe and well-tolerated at a dose level up to 100 mg BID. CLINICAL TRIAL REGISTRATION: NCT03193918. June 19, 2017.

Genomic Methods Identify Homologous Recombination Deficiency in Pancreas Adenocarcinoma and Optimize Treatment Selection.

PURPOSE: Genomic methods can identify homologous recombination deficiency (HRD). Rigorous evaluation of their outcome association to DNA damage response-targeted therapies like platinum in pancreatic ductal adenocarcinoma (PDAC) is essential in maximizing therapeutic outcome. EXPERIMENTAL DESIGN: We evaluated progression-free survival (PFS) and overall survival (OS) of patients with advanced-stage PDAC, who had both germline- and somatic-targeted gene sequencing. Homologous recombination gene mutations (HRm) were evaluated: BRCA1, BRCA2, PALB2, ATM, BAP1, BARD1, BLM, BRIP1, CHEK2, FAM175A, FANCA, FANCC, NBN, RAD50, RAD51, RAD51C, and RTEL1 HRm status was grouped as: (i) germline versus somatic; (ii) core (BRCAs and PALB2) versus non-core (other HRm); and (iii) monoallelic versus biallelic. Genomic instability was compared using large-scale state transition, signature 3, and tumor mutation burden. RESULTS: Among 262 patients, 50 (19%) had HRD (15% germline and 4% somatic). Both groups were analyzed together due to lack of difference in their genomic instability and outcome. Median [95% confidence interval (CI)] follow-up was 21.9 (1.4-57.0) months. Median OS and PFS were 15.5 (14.6-19) and 7 (6.1-8.1) months, respectively. Patients with HRD had improved PFS compared with no HRD when treated with first-line (1L) platinum [HR, 0.44 (95% CI: 0.29-0.67); P < 0.01], but not with 1L-non-platinum. Multivariate analysis showed HRD patients had improved OS regardless of their first-line treatment, but most had platinum exposure during their course. Biallelic HRm (11%) and core HRm (12%) had higher genomic instability, which translated to improved PFS on first-line platinum (1L-platinum) versus 1L-non-platinum. CONCLUSIONS: Pathogenic HRm identifies HRD in patients with PDAC with the best outcome when treated with 1L-platinum. Biallelic HRm and core HRm further enriched benefit from 1L-platinum from HRD.

Efficacy of Combined VEGFR1-3, PDGFα/ß, and FGFR1-3 Blockade Using Nintedanib for Esophagogastric Cancer.

PURPOSE: VEGFR2-directed therapy is commonly used to treat metastatic esophagogastric cancer, but disease progresses in most patients within months. Therapeutic resistance is likely mediated in part by co-occurring amplifications of the genes for multiple oncogenic receptor tyrosine kinases (RTK). We therefore tested the efficacy of combined inhibition of VEGFR1-3, PDGFα/ß, and FGFR1-3 using nintedanib. PATIENTS AND METHODS: Patients with metastatic esophagogastric adenocarcinoma and disease progression on first-line chemotherapy were treated with nintedanib 200 mg twice daily. The primary endpoint was progression-free survival (PFS) at 6 months; secondary endpoints included tumor response and safety. Tumor biopsies were profiled by targeted capture next-generation sequencing (NGS) to identify molecular predictors of drug response. RESULTS: The study achieved its primary endpoint; 6 of 32 patients (19%) were progression-free at 6 months. With a median follow-up of 14.5 months among survivors, median overall survival (OS) was 14.2 months [95% confidence interval (CI), 10.8 months-NR]. Nintedanib was well tolerated; grade ≥ 3 toxicities were uncommon and included grade 3 hypertension (15%) and liver enzyme elevation (4%). FGFR2 alterations were identified in 18% of patients but were not predictive of clinical outcome on nintedanib therapy. Alterations in cell-cycle pathway genes were associated with worse median PFS (1.61 months for patients with cell-cycle pathway alterations vs. 2.66 months for patients without, P = 0.019). CONCLUSIONS: Nintedanib treatment resulted in modest disease stabilization in patients with metastatic esophagogastric cancer. Alterations in cell-cycle pathway genes and increased global copy-number alteration (CNA) burden warrant further study as prognostic or predictive biomarkers.

Assessment of a Watch-and-Wait Strategy for Rectal Cancer in Patients With a Complete Response After Neoadjuvant Therapy.

IMPORTANCE: The watch-and-wait (WW) strategy aims to spare patients with rectal cancer unnecessary resection. OBJECTIVE: To analyze the outcomes of WW among patients with rectal cancer who had a clinical complete response to neoadjuvant therapy. DESIGN, SETTING, AND PARTICIPANTS: This retrospective case series analysis conducted at a comprehensive cancer center in New York included patients who received a diagnosis of rectal adenocarcinoma between January 1, 2006, and January 31, 2015. The median follow-up was 43 months. Data analyses were conducted from June 1, 2016, to October 1, 2018. EXPOSURES: Patients had a clinical complete response after completing neoadjuvant therapy and agreed to a WW strategy of active surveillance and possible salvage surgery (n = 113), or patients underwent total mesorectal excision and were found to have a pathologic complete response (pCR) at resection (n = 136). MAIN OUTCOMES AND MEASURES: Kaplan-Meier estimates were used for analyses of local regrowth and 5-year rates of overall survival, disease-free survival, and disease-specific survival. RESULTS: Compared with the 136 patients in the pCR group, the 113 patients in the WW group were older (median [range], 67.2 [32.1-90.9] vs 57.3 [25.0-87.9] years, P < .001) with cancers closer to the anal verge (median [range] height from anal verge, 5.5 [0.0-15.0] vs 7.0 [0.0-13.0] cm). All 22 local regrowths in the WW group were detected on routine surveillance and treated by salvage surgery (20 total mesorectal excisions plus 2 transanal excisions). Pelvic control after salvage surgery was maintained in 20 of 22 patients (91%). No pelvic recurrences occurred in the pCR group. Rectal preservation was achieved in 93 of 113 patients (82%) in the WW group (91 patients with no local regrowths plus 2 patients with local regrowths salvaged with transanal excision). At 5 years, overall survival was 73% (95% CI, 60%-89%) in the WW group and 94% (95% CI, 90%-99%) in the pCR group; disease-free survival was 75% (95% CI, 62%-90%) in the WW group and 92% (95% CI, 87%-98%) in the pCR group; and disease-specific survival was 90% (95% CI, 81%-99%) in the WW group and 98% (95% CI, 95%-100%) in the pCR group. A higher rate of distant metastasis was observed among patients in the WW group who had local regrowth vs those who did not have local regrowth (36% vs 1%, P < .001). CONCLUSIONS AND RELEVANCE: A WW strategy for select rectal cancer patients who had a clinical complete response after neoadjuvant therapy resulted in excellent rectal preservation and pelvic tumor control; however, in the WW group, worse survival was noted along with a higher incidence of distant progression in patients with local regrowth vs those without local regrowth.

Phase I study of oxaliplatin in combination with gemcitabine, irinotecan, and 5-fluorouracil/leucovorin (G-FLIE) in patients with metastatic solid tumors including adenocarcinoma of the pancreas.

PURPOSE: The aims of this study were to establish the maximum tolerated dose (MTD) of oxaliplatin in combination with fixed doses of gemcitabine, irinotecan, and 5-fluorouracil/leucovorin (G-FLIE) in solid tumors, including advanced pancreatic cancer, and to evaluate the toxicity of the regimen. METHODS: Patients with metastatic solid tumors were treated with a regimen consisting of gemcitabine (500 mg/m(2) by fixed-dose-rate infusion), irinotecan (120 mg/m(2)), leucovorin 300 mg, bolus/infusion 5-fluorouracil (400 and 1,500 mg/m2, respectively), and oxaliplatin at doses from 50 to 85 mg/m(2) according to the escalation schema. Treatment was repeated every 14 days. RESULTS: The study enrolled 25 patients with a median age of 64 years and median Karnofsky performance score of 80. Patients had metastatic adenocarcinomas of pancreas (n = 9), as well as gastroesointestinal, hepatobiliary, or unknown primary tumors. With only one dose limiting toxicity (neutropenia and constipation), the MTD of oxaliplatin was not reached up to the pre-specified maximum level of 85 mg/m(2). Other toxicities predictably included cytopenias, fatigue, sensory neuropathy, nausea/vomiting, diarrhea, and constipation. Four partial responses and ten disease stabilizations were observed. The overall median time to disease progression was 17 weeks (2-110 weeks) with median overall survival of 31.5 weeks (7-139 weeks). CONCLUSIONS: G-FLIE is a tolerable multi-agent chemotherapy regimen with the oxaliplatin dose up to 85 mg/m(2). The combination of full-dose oxaliplatin with gemcitabine, irinotecan, and 5-fluorouracil is feasible with attenuated doses of the drugs, but further optimization is necessary before assessment of efficacy.