Chemotherapy and Immune Checkpoint Blockade for Gastric and Gastroesophageal Junction Adenocarcinoma

Importance

Combining immune checkpoint blockade (ICB) with chemotherapy improves outcomes in patients with metastatic gastric and gastroesophageal junction (G/GEJ) adenocarcinoma; however, whether this combination has activity in the perioperative setting remains unknown.

Objective

To evaluate the safety and preliminary activity of perioperative chemotherapy and ICB followed by maintenance ICB in resectable G/GEJ adenocarcinoma.

Design, Setting, and Participants

This investigator-initiated, multicenter, open-label, single-stage, phase 2 nonrandomized controlled trial screened 49 patients and enrolled 36 patients with resectable G/GEJ adenocarcinoma from February 10, 2017, to June 17, 2021, with a median (range) follow-up of 35.2 (17.4-73.0) months. Thirty-four patients were deemed evaluable for efficacy analysis, with 28 (82.4%) undergoing curative resection. This study was performed at 4 referral institutions in the US.

Interventions

Patients received 3 cycles of capecitabine, 625 mg/m2, orally twice daily for 21 days; oxaliplatin, 130 mg/m2, intravenously and pembrolizumab, 200 mg, intravenously with optional epirubicin, 50 mg/m2, every 3 weeks before and after surgery with an additional cycle of pembrolizumab before surgery. Patients received 14 additional doses of maintenance pembrolizumab.

Main Outcomes and Measures

The primary end point was pathologic complete response (pCR) rate. Secondary end points included overall response rate, disease-free survival (DFS), overall survival (OS), and safety.

Results

A total of 34 patients (median [range] age, 65.5 [25-90] years; 23 [67.6%] male) were evaluable for efficacy. Of these patients, 28 (82.4%) underwent curative resection, 7 (20.6%; 95% CI, 10.1%-100%) achieved pCR, and 6 (17.6%) achieved a pathologic near-complete response. Of the 28 patients who underwent resection, 4 (14.3%) experienced disease recurrence. The median DFS and OS were not reached. The 2-year DFS was 67.8% (95% CI, 0.53%-0.87%) and the OS was 80.6% (95% CI, 0.68%-0.96%). Treatment-related grade 3 or higher adverse events for evaluable patients occurred in 20 patients (57.1%), and 12 (34.3%) experienced immune-related grade 3 or higher adverse events.

Conclusion and Relevance

In this trial of unselected patients with resectable G/GEJ adenocarcinoma, capecitabine, oxaliplatin, and pembrolizumab resulted in a pCR rate of 20.6% and was well tolerated. This trial met its primary end point and supports the development of checkpoint inhibition in combination with perioperative chemotherapy in locally advanced G/GEJ adenocarcinoma.

Trial Registration

ClinicalTrials.gov Identifier: NCT02918162.

A Single-Arm Phase II Trial of Sitravatinib in Advanced Well-Differentiated/Dedifferentiated Liposarcoma

PURPOSE

To evaluate sitravatinib, an inhibitor of multiple receptor tyrosine kinases (RTK), for the treatment of well-differentiated/dedifferentiated liposarcoma (WD/DD LPS).

PATIENTS AND METHODS

This multicenter, open-label, Phase II trial enrolled patients with advanced WD/DD LPS who had received at least one prior systemic regimen and had progression within 12 weeks of enrollment. Patients received sitravatinib 150 mg (later amended to 120 mg) orally daily. A Simon two-stage design was used to evaluate for an improvement in the primary endpoint, progression-free rate at 12 weeks (PFR12), from 20% to 40%. Secondary endpoints included antitumor activity and safety. A subset of patients underwent paired biopsies analyzed using reverse-phase protein array.

RESULTS

Twenty-nine patients enrolled. Median age was 62 years and 31% had received 3 or more prior lines. Most patients (93%) had DDLPS or mixed WD/DD LPS. Overall, 12 of 29 patients (41%) were alive and progression-free at 12 weeks and the study met the primary endpoint. There were no confirmed responses. Median progression-free survival was 11.7 weeks [95% confidence interval (CI): 5.9-35.9] and median overall survival was 31.7 weeks (95% CI: 18.1-90.1). The most common treatment-related adverse events were diarrhea (59%), hypertension (52%), hoarseness (41%), mucositis (31%), and nausea (31%). Baseline expression of phospho-RTKs was not significantly different between patients with and without clinical benefit from sitravatinib, but the number of samples was small.

CONCLUSIONS

Sitravatinib provided a PFR12 of 41% and meaningful disease control in a subset of patients with advanced, progressive WD/DD LPS.

Intermittent MEK inhibition for the treatment of metastatic uveal melanoma

Introduction

Uveal melanoma (UM) is associated with poor outcomes in the metastatic setting and harbors activating mutations resulting in upregulation of MAPK signaling in almost all cases. The efficacy of selumetinib, an oral allosteric inhibitor of MEK1/2, was limited when administered at a continual dosing schedule of 75 mg BID. Preclinical studies demonstrate that intermittent MEK inhibition reduces compensatory pathway activation and promotes T cell activation. We hypothesized that intermittent dosing of selumetinib would reduce toxicity, allow for the administration of increased doses, and achieve more complete pathway inhibition, thus resulting in improved antitumor activity.

Methods

We conducted a phase Ib trial of selumetinib using an intermittent dosing schedule in patients with metastatic UM. The primary objective was to estimate the maximum tolerated dose (MTD) and assess safety and tolerability. Secondary objectives included assessment of the overall response rate (RR), progression-free survival (PFS) and overall survival (OS). Tumor biopsies were collected at baseline, on day 3 (on treatment), and between days 11-14 (off treatment) from 9 patients for pharmacodynamic (PD) assessments.

Results

29 patients were enrolled and received at least one dose of selumetinib across 4 dose levels (DL; DL1: 100 mg BID; DL2: 125 mg BID; DL3: 150 mg BID; DL4: 175 mg BID). All patients experienced a treatment-related adverse event (TRAE), with 5/29 (17%) developing a grade 3 or higher TRAE. Five dose limiting toxicities (DLT) were observed: 2/20 in DL2, 2/5 in DL3, 1/1 in DL4. The estimated MTD was 150 mg BID (DL3), with an estimated probability of toxicity of 29% (90% probability interval 16%-44%). No responses were observed; 11/29 patients achieved a best response of stable disease (SD). The median PFS and OS were 1.8 months (95% CI 1.7, 4.5) and 7.1 months (95% CI 5.3, 11.5). PD analysis demonstrated at least partial pathway inhibition in all samples at day 3, with reactivation between days 11-14 in 7 of those cases.

Conclusions

We identified 150 mg BID as the MTD of intermittent selumetinib, representing a 100% increase over the continuous dose MTD (75 mg BID). However, no significant clinical efficacy was observed using this dosing schedule.

Adjuvant crizotinib in high-risk uveal melanoma following definitive therapy

Introduction

Approximately 40% of patients with uveal melanoma (UM) will develop metastatic disease. Tumors measuring at least 12mm in basal diameter with a class 2 signature, as defined by a widely used gene expression-profiling test, are associated with significantly higher risk of metastasis, with a median time to recurrence of 32 months. No therapy has been shown to reduce this risk.

Materials and Methods

This was a single-arm, multicenter study in patients with high-risk UM who received definitive treatment of primary disease and had no evidence of metastasis. Patients were consecutively enrolled to receive 12 four-week cycles of adjuvant crizotinib at a starting dose of 250mg twice daily and were subsequently monitored for 36 months. The primary outcome of this study was to assess recurrence-free survival (RFS) of patients with high-risk UM who received adjuvant crizotinib.

Results

34 patients enrolled and received at least one dose of crizotinib. Two patients were unevaluable due to early withdrawal and loss to follow-up, leaving 32 patients evaluable for efficacy. Eight patients (25%) did not complete the planned 48-week course of treatment due to disease recurrence (n=5) or toxicity (n=3). All patients experienced at least one adverse event (AE), with 11/34 (32%) experiencing a Common Terminology Criteria for Adverse Events (CTCAE) grade 3 or 4 AE. After a median duration of follow up of 47.1 months, 21 patients developed distant recurrent disease. The median RFS was 34.9 months (95% CI (Confidence Interval), 23-55 months), with a 32-month recurrence rate of 50% (95% CI, 33-67%). Analysis of protein contents from peripheral blood extracellular vesicles in a subset of patient samples from baseline, on-treatment, and off-treatment, revealed a change in protein content associated with crizotinib exposure, however without a clear association with disease outcome.

Conclusions

The use of adjuvant crizotinib in patients with high-risk UM did not result in improved RFS when compared to historical controls. Analysis of blood extracellular vesicles revealed changes in protein content associated with treatment, raising the possibility of future use as a biomarker. Further investigation of adjuvant treatment options are necessary for this challenging disease.

Abstract CT009: Phase II trial of perioperative pembrolizumab plus capecitabine and oxaliplatin followed by adjuvant pembrolizumab for resectable gastric and gastroesophageal junction (GC/GEJ) adenocarcinoma

Background: Perioperative therapy for locally advanced (LA) GC/GEJ adenocarcinoma is standard of care. Although immune checkpoint blockade (ICB) following chemoradiotherapy and resection significantly improves disease free survival (DFS) for esophageal cancer, the effectiveness of ICB together with chemotherapy in LA GC/GEJ cancer is unknown.

Methods: This is a multicenter, single-arm, phase II clinical trial of pembrolizumab 200 mg every 3 weeks with capecitabine 625 mg/m2 twice daily and oxaliplatin 130 mg/m2 every 3 weeks (CAPOX) in patients with resectable GC/GEJ adenocarcinoma. Subjects with ECOG PS of 0-1 received CAPOX with pembrolizumab for 3 cycles prior to and 3 cycles following surgery with an additional cycle of pembrolizumab just prior to surgery and 12 months of maintenance pembrolizumab following adjuvant chemoimmunotherapy. The primary endpoint was pathologic complete response (pCR) rate. The study had 80% power to detect an increase in pCR rate from 3% to 15% with a one-sided alpha of 0.05. Secondary endpoints included overall response rate, DFS, and overall survival (OS). This study was registered with ClinicalTrials.gov (NCT02918162).

Results: Between 02/10/2017 and 06/17/2021, 36 patients were enrolled with 34 (21 gastric and 13 GEJ) evaluable for efficacy. The median age was 65 years and 17 (50%) patients had an ECOG PS of 1. In total, 29 (85%) patients underwent resection. Seven patients achieved a pCR (20.6% of evaluable patients and 24.1% of those who underwent resection). An additional 6 (17.6%) patients achieved a near CR and 8 (23.5%) demonstrated a significant treatment effect on pathologic review. One patient was deemed unfit for surgery, 2 expired prior to surgery, and 2 were found to have metastatic disease during surgery. At the time of data cut-off, the median follow-up was 19 mo. Of those who underwent resection, 4 (13.7%) experienced disease recurrence and 5 (17.2%) expired. The probability of survival at 1 and 2 years was 0.91 (0.82-1.0) and 0.80 (0.64-0.99), respectively. The median DFS and OS have not been reached. Of the 35 patients who received treatment, treatment related adverse events (AEs) of grade greater than or equal to 3 were reported in 18 (51%) patients. Grade greater than or equal to 3 immune-related AEs were reported in 10 (29%) patients. Three grade 5 AEs occurred, two possibly treatment-related (gastric hemorrhage and gastric perforation) and one unrelated to treatment (cardiac arrest).

Conclusion: In LA GC/GEJ adenocarcinoma, the combination CAPOX and pembrolizumab resulted in a pCR rate of 20.6%. The combination was well tolerated and 85.3% of patients underwent surgical resection. This trial met its primary endpoint supporting further investigation of this regimen as an alternative for patients who are unlikely to tolerate triple combination chemotherapy. Correlative studies are in progress.

Citation Format: Alexander Grenander Raufi, Shing Lee, Michael May, Armando Del Portillo, Naomi Sender, Sarah Sta Ana, Katarzyna Gautier, Emily Alouani, Haeseong Park, Paul Oberstein, Manish Shah, Gulam A. Manji. Phase II trial of perioperative pembrolizumab plus capecitabine and oxaliplatin followed by adjuvant pembrolizumab for resectable gastric and gastroesophageal junction (GC/GEJ) adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT009.

A randomized phase Ib/II study of intermittent androgen deprivation therapy plus nivolumab with or without interleukin-8 blockade in men with hormone-sensitive prostate cancer (MAGIC-8)

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Background: Immunotherapy has limited efficacy in castration-resistant prostate cancer. Androgen deprivation therapy (ADT) has significant immunomodulatory effects and initially induces a complex immune infiltrate before castration-resistance develops. However, ADT also recruits immunosuppressive myeloid cells to the tumor microenvironment by increasing interleukin-8 (IL-8). We conducted a phase Ib/II clinical trial of immunotherapy plus ADT in men with recurrent castration-sensitive prostate cancer (CSPC). We hypothesized that anti-PD-1 (nivolumab) +/- anti-IL-8 (BMS-986253) given at the time of castration could induce anti-tumor immune responses and decrease disease progression. Methods: MAGIC-8 was a multicenter, phase Ib/II study evaluating nivolumab +/- BMS-986253 combined with a short course of degarelix acetate in patients with recurrent CSPC and rapid PSA doubling time (≤ 12 mos). In the Phase Ib portion, patients were treated with nivolumab (480mg Q4W) for 8 wks followed by nivolumab plus degarelix for an additional 16 wks. In the phase II portion, patients were randomized 1:2 to nivolumab + degarelix (Arm A) versus nivolumab + BMS-986253 (2400mg Q2W) + degarelix (Arm B). The primary endpoints were PSA recurrence at 10 mos following randomization and safety. Key secondary endpoints included biochemical recurrence-free survival (bPFS), time to recovery of testosterone (> 150ng/dl), and bPFS after recovery of testosterone. Results: Between October 16, 2019 and March 9, 2021, 59 patients were enrolled. The first 15 patients were treated on Arm A followed by 1:2 randomization to Arm A (N = 15) versus Arm B (N = 29). Median follow up was 11.6 mos at the data cutoff (1/24/22). Patients treated on Arm A had a significantly lower rate of PSA relapse (17.39%) at 10 mos compared to historical controls (p = < 0.001), including a subgroup of patients (6.67%) with recovery of testosterone and no PSA relapse at > 2 years of follow up. Median time-to-recovery of testosterone was 12.7 mos, median bPFS was 14.0 mos and median bPFS after recovery of testosterone was 5.5 mos. In Arm B, there was no difference in PSA relapse at 10 mos (35%, p = 0.09), median time-to-recovery of testosterone, median bPFS and median bPFS after recovery of testosterone compared to historical controls. Treatment in both arms was well tolerated with a lower rate of grade 3-4 treatment-related adverse events in Arm B compared to Arm A (3.5% vs 12.9%). Conclusions: A short course of ADT plus nivolumab may decrease the rate of PSA relapse and lead to durable long-term responses after recovery of testosterone in a subset of patients. These data support further evaluation of combining nivolumab with ADT in CSPC. Although the addition of BMS-986253 did not improve rate of PSA relapse, we observed significantly less toxicity with the addition of IL-8 inhibition. Clinical trial information: NCT03689699.

Adjuvant crizotinib in high-risk uveal melanoma following definitive therapy

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Background: Uveal melanomas (UM) measuring at least 12mm in base diameter with a class 2 signature as defined by gene expression profiling (DecisionDx-UM) are characterized by high metastatic risk, with a median time to recurrence of 32 months. No therapy has been shown to reduce this risk. The growth factor receptor Met is highly expressed in UM. We have previously shown that crizotinib, an inhibitor of Met, is an effective adjuvant therapy in preclinical models (Surriga et al, Mol Cancer Ther 2013). We therefore conducted a phase II study of adjuvant crizotinib in high-risk UM. Methods: Eligibility included: primary lesion ≥12mm in base diameter; class 2 by DecisionDx-UM testing; definitive therapy within 120 days before starting crizotinib; and, no evidence of metastatic disease. Patients (pts) received 12 four-week cycles of crizotinib (250 mg twice daily). Surveillance imaging (chest CT and MRI abdomen/pelvis) were performed q3 months. The primary endpoint was distant relapse-free survival (RFS). Secondary endpoints were overall survival (OS) and toxicity. We hypothesized that the addition of crizotinib would increase the 32 month RFS from 50% to 75% (α = 0.05; β = 0.11). Results: As of 1/31/2020, 34 pts had enrolled and received at least one dose of study drug with median age of 60 (range, 26-86); 41% female; and median ECOG PS 0 (range, 0-1). 2 pts could not be evaluated for the primary endpoint due to early withdrawal and loss to follow-up. The median time from primary treatment to crizotinib initiation was 60 days (range, 0-106). All pts experienced a treatment-related adverse event (AE) of any grade. 11/34 (32%) experienced a grade 3 or 4 AE, the most common being transaminase elevation (n = 8/11). 9 pts (28%) did not complete the full 48-week treatment course due to disease recurrence (n = 5) or toxicity (n = 4). An additional 5 pts required dose reduction due to hepatic toxicity or diarrhea. 15/32 evaluable pts developed distant disease relapse, with 14 developing relapse within 32 months. With a median duration of follow up of 28.7 months, the median RFS was 30.6 months (95% CI: 27.8-58.5%). The median OS was not reached. Conclusions: The use of adjuvant crizotinib in patients with high-risk UM did not reduce rates of relapse in this multicenter, single arm trial. 9/32 (28%) pts required dose modification or discontinuation due to AE which may have limited efficacy. Further investigations of adjuvant treatment options are warranted. Clinical trial information: NCT02223819.

Phase 1 combination therapy with pexidartinib (PEX) and sirolimus (S) to target tumor-associated macrophages in pigmented villonodular synovitis, malignant peripheral nerve sheath tumors, and other soft tissue sarcomas

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Background: No effective therapy exists for unresectable malignant peripheral nerve sheath tumors (MPNSTs). We previously reported that the combination of PEX and the mTOR inhibitor S synergistically inhibited MPNST growth (CCR 20: 3146, 2014) by depleting M2 TAMs and by inhibiting receptor tyrosine kinases (RTKs), including c-KIT, PDGFR, CSF1R. We characterized the safety, tolerability, recommended phase 2 dose (RP2D) of PEX plus S in all sarcoma sub-types. Methods: Patients (pts) received PEX plus S orally in 28 days cycle as per Table. The RP2D was determined using the time-to-event continual reassessment method (TITE-CRM) in advanced sarcoma who have progressed on standard therapy. DLT was defined as any need for a dose reduction. Results: 24 pts were accrued (Acr) of which 18 were evaluable (MPNST – 6, pigmented villonodular synovitis (PVNS) – 3, leiomyosarcoma – 5, and other – 9). The mean age was 46y, 56% were male, and 67% had greater than 2 prior therapies. Most common ( > 20%) grade 2 or higher TEAEs were anemia (33%), WBC count decrease (28%), fatigue, neutropenia, and lymphopenia (22% each). There were 5 dose limiting toxicities (DLT): 2 for elevated LFTs both of which resolved with dose reduction, 2 for supra-therapeutic S trough levels, and 1 for grade 5 dehydration at dose level (DL) 3. Four subjects experienced a partial response (PR; -44% to -77% by RECIST, 18 – 61 wks on therapy). Seven subjects experienced stable disease (SD; +19.7% to -20.7% by RECIST; 9.4 – 30 wks on therapy). Five subjects progressed on therapy and two subjects experienced early DLTs and did not undergo tumor assessment. The RP2D is DL 3 (S 2mg/PEX 1000mg) with an estimated probability of DLT of 26.7% as determined by TITE-CRM. This recommendation is based on a target DLT rate of 25%. TAMs and immune subtypes from available tissue specimens and historical controls will be presented. Conclusions: 1000mg of PEX in combination with 2mg of S daily has an acceptable safety profile. Objective responses and durable SD was observed in PNVS and MPNST patients justifying proceeding with a multi-center single arm phase 2 study in advanced MPNST. Clinical trial information: NCT02584647. [Table: see text]

A phase I clinical trial of dTCApFs, a derivative of a novel human hormone peptide, for the treatment of advanced/metastatic solid tumors

The aim of the present phase I first-in-human study was to investigate the safety/efficacy of dTCApFs (a novel hormone peptide that enters cells through the T1/ST2 receptor), in advanced/metastatic solid tumors. The primary objective of this open-label dose-escalation study was to determine the safety profile of dTCApFs. The study enrolled patients (aged ≥18 years) with pathologically confirmed locally advanced/metastatic solid malignancies, who experienced treatment failure or were unable to tolerate previous standard therapy. The study included 17 patients (64% male; median age, 65 years; 47% colorectal cancer, 29% pancreatic cancer). The patients received 1-3 cycles of escalating dTCApFs doses (6-96 mg/m²). The mean number ± standard deviation of treatment cycles/patient was 3.2±1.4; no dose-limiting toxicities were observed up to a dose of 96 mg/m², and the maximum tolerated dose was not reached. Half-life, maximal plasma concentration, and dTCApFs exposure were found to be linearly correlated with dose. Five patients were treated for ≥3 months (12, 24, 48 mg/m²) and experienced stable disease throughout the treatment period, and 1 experienced pathological complete response. Analysis of serum biomarkers revealed decreased levels of angiogenic factors at dTCApFs concentrations of 12-48 mg/m², increased levels of anticancer cytokines, and induction of the endoplasmic reticulum (ER) stress biomarker GRP78/BiP. Efficacy and biomarker data suggest that patients whose tumors were T1/ST2-positive exhibited a better response to dTCApFs. In conclusion, dTCApFs was found to be safe/well-tolerated, and potentially efficacious, with linear pharmacokinetics. Consistent with preclinical studies, the mechanism through which dTCApFs exerts anticancer effects appears to involve induction of ER stress, suppression of angiogenesis, and activation of the innate immune response. However, further studies are warranted.