Nivolumab plus ONC201 plus in microsatellite stable (MSS) metastatic colorectal cancer (mCRC) patients: a Brown University Oncology Research Group phase Ib/II study (BrUOG379).

Background: Immune checkpoint inhibitors alone, or in combination with chemotherapy failed to provide meaningful clinical activity for patients with microsatellite stable (MSS) colorectal cancer (CRC). ONC201 is a small molecule that inactivates AKT and ERK signaling and actives the TRAIL pathway. Preclinical studies indicated potential benefits of combining ONC201 with checkpoint inhibitors. This is a phase Ib/II trial of ONC201 plus nivolumab for patient with MSS CRC who progressed on standard treatment. Methods: Enrolled patients received ONC201 plus nivolumab in a dose de-escalation fashion to determine the maximum tolerated dose (MTD). Additional patients were enrolled in the dose-expansion cohort. ONC201 at a dose of 625 mg was given orally at day -7 of cycle 1, followed by weekly dosing. Nivolumab was given every 2 weeks at 240 mg IV starting on day 1 of every cycle (cycle =28 days). The primary end point was dose-limiting toxicity (DLT) during the observation window (run-in dose day -7, cycle 1 to assessment pre-dosing cycle 2). The plan was to enroll 28 additional patients at the MTD so that a total of 34 patients would be treated at the MTD. Pharmacokinetics (PKs) and tumor biopsies were collected at several time points per study protocol. Results: A total of 13 patients (8 patients in the dose escalation *6 evaluable*) were enrolled between December 4, 2019 and March 2021. All patients had received ≥2 previous lines of chemotherapy and had confirmed microsatellite stability or mismatch repair-proficient tumors. No DLTs were observed with 625 mg ONC201 in the first three patients. Three additional patients were enrolled at the same dose to confirm safety. Two patients progressed during the DLT period and had to be replaced. During the dose-expansion part, five patients were enrolled and none required dose reduction or modification. No objective tumor response was observed in the 13 treated patients. Disease progression was confirmed at the time of the first imaging evaluation at 8 weeks following cycle 2. Post discussion at the Data and Safety Monitoring Board (DSMB) on May 25, 2021, the principal investigator (PI) and Committee voted to close the study to new patient enrollment prior to reaching accrual of 34 patients, secondary to lack of efficacy. Conclusions: In this study of patients with advanced MSS CRC, combination ONC201/nivolumab was well-tolerated; objective responses to ONC201/nivolumab were not observed.

The Brown University Oncology Group Experience With FOLFOX + Nab-paclitaxel [FOLFOX-A] for Metastatic and Locally Advanced Pancreatic, BrUOG-292 and BrUOG-318.

OBJECTIVES: To evaluate response rate, toxicity, and efficacy of the novel combination of nab-paclitaxel, oxaliplatin, 5-fluorouracil, and leucovorin [FOLFOX-A] in patients with advanced pancreatic ductal adenocarcinoma [PDAC]. METHODS: BrUOG-292 and BrUOG-318 were two concurrently run, prospective, single-arm phase II studies evaluating FOLFOX-A as first-line therapy in patients with metastatic and locally advanced/borderline resectable PDAC respectively. The FOLFOX-A regimen consisted of 5-fluorouracil, 1200 mg/m 2 /d as a continuous intravenous (IV) infusion over 46 hours, leucovorin 400 mg/m 2 IV, oxaliplatin 85 mg/m 2 IV, and nab-paclitaxel 150 mg/m 2 IV on day 1 every 14 days up to a maximum of 12 cycles. Patients with locally advanced or borderline resectable disease were permitted to stop treatment after 6 cycles and receive radiation therapy and/or surgical exploration if feasible. The primary end point was overall response rate [ORR]. Secondary end points were median progression-free survival [PFS], median overall survival [OS], and safety. RESULTS: Seventy-eight patients with previously untreated PDAC were enrolled between June 2014 and November 2019; 76 patients were evaluable. The median follow-up was 40 months and 32 months, respectively. overall response rate was 34%. Among the patients enrolled on BrUOG-292 [48 patients], the PFS was 5 months and OS was 11 months, respectively. For those enrolled on BrUOG 318 [28 patients], the PFS was 11 months and OS was 22 months. Treatment-related toxicities included grade 3 fatigue [40%], diarrhea [14%], and neuropathy [2%]. CONCLUSIONS: The combination of FOLFOX-A has promising activity in PDAC and may represent an alternative to FOLFIRINOX when reduction of gastrointestinal toxicity is required.

Assessment of Capecitabine and Bevacizumab With or Without Atezolizumab for the Treatment of Refractory Metastatic Colorectal Cancer: A Randomized Clinical Trial.

Importance: Cotargeting vascular endothelial growth factor and programmed cell death 1 or programmed cell death ligand 1 may produce anticancer activity in refractory metastatic colorectal cancer (mCRC). The clinical benefit of atezolizumab combined with chemotherapy and bevacizumab remains unclear for the treatment of mCRC. Objectives: To assess whether the addition of atezolizumab to capecitabine and bevacizumab therapy improves progression-free survival (PFS) among patients with refractory mCRC and to perform exploratory analyses among patients with microsatellite-stable (MSS) disease and liver metastasis. Design, Setting, and Participants: This double-blind phase 2 randomized clinical trial enrolled 133 patients between September 25, 2017, and June 28, 2018 (median duration of follow-up for PFS, 20.9 months), with data cutoff on May 4, 2020. The study was conducted at multiple centers through the Academic and Community Cancer Research United network. Adult patients with mCRC who experienced disease progression while receiving fluoropyrimidine, oxaliplatin, irinotecan, bevacizumab, and anti-epidermal growth factor receptor antibody therapy (if the patient had a RAS wild-type tumor) were included. Interventions: Patients were randomized (2:1) to receive capecitabine (850 or 1000 mg/m2) twice daily on days 1 to 14 and bevacizumab (7.5 mg/kg) on day 1 plus either atezolizumab (1200 mg; investigational group) or placebo (placebo group) on day 1 of each 21-day cycle. Main Outcomes and Measures: The primary end point was PFS; 110 events were required to detect a hazard ratio (HR) of 0.65 with 80% power (1-sided α = .10). Secondary end points were objective response rate, overall survival (OS), and toxic effects. Results: Of 133 randomized patients, 128 individuals (median age, 58.0 years [IQR, 51.0-65.0 years]; 77 men [60.2%]) were assessed for efficacy (82 in the investigational group and 46 in the placebo group). Overall, 15 patients (11.7%) self-identified as African American or Black, 8 (6.3%) as Asian, 1 (0.8%) as Pacific Islander, 101 (78.9%) as White, 1 (0.8%) as multiple races (Asian, Native Hawaiian/Pacific Islander, and White), and 2 (1.6%) as unknown race or unsure of race. Microsatellite-stable disease was present in 110 patients (69 in the investigational group and 41 in the placebo group). Median PFS was 4.4 months (95% CI, 4.1-6.4 months) in the investigational group and 3.6 months (95% CI, 2.2-6.2 months) in the placebo group (1-sided log-rank P = .07, a statistically significant result; HR, 0.75; 95% CI, 0.52-1.09). Among patients with MSS and proficient mismatch repair, the HR for PFS was 0.66 (95% CI, 0.44-0.99). The most common grade 3 or higher treatment-related adverse events in the investigational vs placebo groups were hypertension (6 patients [7.0%] vs 2 patients [4.3%]), diarrhea (6 patients [7.0%] vs 2 patients [4.3%]), and hand-foot syndrome (6 patients [7.0%] vs 2 patients [4.3%]). One treatment-related death occurred in the investigational group. In the investigational group, the response rate was higher among patients without liver metastasis (3 of 13 individuals [23.1%]) vs with liver metastasis (4 of 69 individuals [5.8%]). The benefit of atezolizumab for PFS and OS was greater among patients without vs with liver metastasis (primary analysis of PFS: HR, 0.63 [95% CI, 0.27-1.47] vs 0.77 [95% CI, 0.51-1.17]; OS: HR, 0.33 [95% CI, 0.11-1.02] vs 1.14 [95% CI, 0.72-1.81]). Conclusions and Relevance: In this randomized clinical trial, the addition of atezolizumab to capecitabine and bevacizumab therapy provided limited (ie, not clinically meaningful) clinical benefit. Patients with MSS and proficient mismatch repair tumors and those without liver metastasis benefited more from dual inhibition of the vascular endothelial growth factor and programmed cell death 1 or programmed cell death ligand 1 pathways. Trial Registration: ClinicalTrials.gov Identifier: NCT02873195.

Colon cancer and immunotherapy-can we go beyond microsatellite instability?

Immune checkpoint blockade (ICB) has changed the landscape of cancer therapy in multiple tumor types since the first agent, Ipilimumab, was first FDA approved for the treatment of metastatic melanoma in 2011. Its role in GI Cancers, particularly in colon cancers, has not been as robust as in other tumor types but select patients with DNA mismatch repair defects, even those who has progressed on multiple standard chemotherapeutic regimens have demonstrated significant, almost unprecedented, responses in this multidrug refractory population. Unfortunately, these cases represent only a small percentage of colon cancer patients with little efficacy in the 95% of metastatic colon cancers who have proficient DNA mismatch repair. Multiple strategies have been, and are currently being, evaluated to determine the potential benefits of this drug class to microsatellite stable (MSS) patients.

Adjuvant FOLFOX+Nab-Paclitaxel (FOLFOX-A) for Pancreatic Cancer: A Brown University Oncology Research Group Phase II Study (BrUOG295).

OBJECTIVES: Multiple clinical trials have established a role for adjuvant chemotherapy for patients with pancreatic ductal adenocarcinoma. Adjuvant FOLFIRINOX increases survival as compared with gemcitabine but with increased toxicity. FOLFOX+nab-paclitaxel (FOLFOX-A) was developed by the Brown University Oncology Research Group (BrUOG) as an alternative to FOLFIRINOX. This phase II trial explored the feasibility and toxicity of adjuvant FOLFOX-A in patients who have completed resection for pancreatic ductal adenocarcinoma. PATIENTS AND METHODS: Patients with resected pancreatic ductal adenocarcinoma were eligible. The primary objective was to determine the feasibility of adjuvant FOLFOX-A. Patients experiencing grade 2 neuropathy received a 20% reduction of oxaliplatin. Secondary end points were disease-free survival, and overall survival. RESULTS: Between June 2014 and October 2018, 25 patients were enrolled following surgical resection. The median number of cycles completed was 9.5. Median disease-free survival was 19.7 months (95% confidence interval, 10.3 to not reached) and median overall survival was 53.5 months (95% confidence interval, 24.2 to not reached). The most common treatment-related grade 3 or greater adverse events were fatigue (58%), nausea (13%), and neutropenia (26%). Fourteen patients had grade 2 neuropathy (58%) and 1 patient (4%) had grade 3 neuropathy. Only 2 patients (8%) had grade 3 diarrhea. CONCLUSIONS: Adjuvant FOLFOX-A is a feasible multi-agent adjuvant treatment regimen and, with further validation, could be an alternative to FOLFIRINOX.