Ma, Wen Wee

Abstract Background Optimal treatment following first-line immunotherapy for advanced hepatocellular carcinoma (HCC) remains uncertain. This study evaluated futibatinib, a pan-FGFR inhibitor, combined with pembrolizumab in previously treated patients with FGF19-expressing HCC. Methods Eligible patients were ≥18 years old with advanced HCC, prior systemic therapy, Child-Pugh A-B7 liver function, ECOG 0–2, and FGF19 overexpression. Patients received futibatinib 20 mg orally daily plus pembrolizumab 200 mg intravenously every 3 weeks. The primary endpoint was progression-free survival at 6 months (PFS6). Secondary endpoints included overall survival (OS), objective response rate (ORR), quality of life, and safety. Results Between August 2021 and March 2024, 14 patients enrolled and 13 were evaluable. Median age was 72 years (range, 60–87), 53.8% were male, 92.3% had Child-Pugh A liver function, and all had received prior immunotherapy. Median progression-free survival was 15 weeks (95% CI, 9.0–NE), with a PFS6 rate of 23.1% (95% CI, 8.6–62.3%). ORR was 0% (95% CI, 0–24.7%), while stable disease was observed in 53.9% of patients. Median OS was 55.7 weeks (95% CI, 47.3–NE). Grade ≥3 adverse events occurred in 69.2% of patients, and grade ≥4 adverse events in 15.4%. One grade 5 event (acute-on-chronic kidney injury) was deemed unrelated to treatment. Common adverse events included hyperphosphatemia, fatigue, diarrhea, elevated transaminases, dry eye, nail changes, rash, and oral mucositis. Conclusions Futibatinib plus pembrolizumab demonstrated an acceptable safety profile but did not meet efficacy thresholds supporting further study in FGF19-expressing HCC. Effective post-immunotherapy treatment strategies remain an unmet need.

Abstract Purpose: Recent advances have seen the development of targeted therapeutics against the receptor tyrosine kinase (RTK)/RAS/MAPK pathway, which, when aberrantly activated, drives the malignant transformation of many cancer indications. However, the efficacy of inhibitors targeting single molecules is dampened by pathway feedback activation and acquired drug resistance. We seek to evaluate the application of JAB-3312 (sitneprotafib), a potent inhibitor of SHP2, in RTK/RAS/MAPK pathway–targeted combination therapies. Furthermore, SHP2 plays a vital role in PD-1–mediated immunosuppression. The rational combination of JAB-3312 with PD-1 blocking therapies is also explored. Experimental Design: Biochemical and cellular assays were applied to evaluate the potency of JAB-3312 in SHP2 inhibition. Tumor cell lines and cell line– and patient-derived xenografts were used to test different combinations of JAB-3312 with KRASG12C, MEK, EGFR, and PD-1 inhibitors. Results: JAB-3312 produced potent in vitro inhibition of SHP2 activity and downstream ERK phosphorylation, with IC50 values of 1.44 nmol/L and 0.68 to 4.84 nmol/L, respectively. When used in combination, JAB-3312 significantly increased the antitumor activity of the KRASG12C inhibitor glecirasib in naïve and resistant models. The combination of JAB-3312 with MEK inhibitors significantly delayed RTK signaling reactivation and enhanced tumor growth inhibition in KRAS-mutated cancer models. The JAB-3312–osimertinib combination exhibited great efficacy in osimertinib-resistant non–small cell lung cancer models. Additionally, JAB-3312 enhanced the efficacy of PD-1 blockade therapies by promoting an antitumor microenvironment. Representative cases of patients who responded to the combination therapies from two ongoing clinical trials (NCT05288205 and NCT04720976) were reported. Conclusions: JAB-3312 in combination with RTK/RAS/MAPK or PD-1 blockade therapies is a promising strategy that warrants further clinical investigation.

Abstract Purpose: The safety, pharmacokinetics, and efficacy of elraglusib, a glycogen synthase kinase-3β (GSK-3β) small-molecule inhibitor, as monotherapy or combined with chemotherapy, in patients with relapsed or refractory solid tumors or hematologic malignancies was studied. Patients and Methods: Elraglusib (intravenously twice weekly in 3-week cycles) monotherapy dose escalation was followed by dose escalation with eight chemotherapy regimens (gemcitabine, doxorubicin, lomustine, carboplatin, irinotecan, gemcitabine/nab-paclitaxel, paclitaxel/carboplatin, and pemetrexed/carboplatin) in patients previously exposed to the same chemotherapy. Results: Patients received monotherapy (n = 67) or combination therapy (n = 171) elraglusib doses 1 to 15 mg/kg twice weekly. The initial recommended phase II dose (RP2D) of elraglusib was 15 mg/kg twice weekly and was defined, without dose-limiting toxicity observation, due to fluid volumes necessary for drug administration. The RP2D was subsequently reduced to 9.3 mg/kg once weekly to reduce elraglusib-associated central/peripheral vascular access catheter blockages. Other common elraglusib-related adverse events (AE) included transient visual changes and fatigue. Grade ≥3 treatment-emergent AEs occurred in 55.2% and 71.3% of patients on monotherapy and combination therapy, respectively. Part 1 monotherapy (n = 62) and part 2 combination (n = 138) patients were evaluable for response. In part 1, a patient with melanoma had a complete response, and a patient with acute T-cell leukemia/lymphoma had a partial response (PR). In part 2, seven PRs were observed, and the median progression-free survival and overall survival were 2.1 [95% confidence interval (CI), 2–2.6] and 6.9 (95% CI, 5.7–8.4) months, respectively. Conclusions: Elraglusib had a favorable toxicity profile as monotherapy and combined with chemotherapy and was associated with clinical benefit supporting further clinical evaluation in combination with chemotherapy.

PURPOSE Pancreatic cancer (PC) carries a poor prognosis with high rates of unresectable/metastatic disease at diagnosis, recurrence after resection, and few systemic therapy options. Deficient mismatch repair (dMMR)/high microsatellite instability (MSI-H) PCs demonstrated uncharacteristically poor outcomes in KEYNOTE-158, evaluating pembrolizumab in MSI-H solid tumors. Our study aggregates the Mayo Clinic experience with dMMR/MSI-H PCs, characterizing the clinical, molecular, and treatment response patterns with a focus on response to immune checkpoint inhibitors (ICIs). METHODS Retrospective data were collected from the electronic medical record from December 2009 to February 2023. Patients were included if they had a pathologically confirmed pancreatic malignancy and had (1) deficient expression of mismatch repair (MMR) proteins by tumor immunohistochemistry, (2) pathogenic mutation of MMR genes on genomic sequencing, and/or (3) MSI-H by polymerase chain reaction. RESULTS Thirty-two patients were identified for inclusion, with all stages of disease represented. Sixteen of these patients underwent surgery or chemoradiotherapy. Of these patients, uncharacteristically favorable responses were seen, with a recurrence rate of only 19% (n = 3) despite a median follow-up of 25 months. In the palliative setting, excellent responses to ICI were seen, with overall response rate (ORR) of 75% (20% complete response). Median time to disease progression was not reached. Response rates to cytotoxic chemotherapy in the palliative setting were poor, with 30% ORR and median time to progression of 4 months. We observed a high rate of discrepancy between MMR and MSI testing methods, representing 19% of the entire cohort and 26% of evaluable cases. CONCLUSION Our data argue for the preferential use of ICI over cytotoxic chemotherapy in any patient with dMMR/MSI-H PC requiring systemic therapy, including in the metastatic and adjuvant/neoadjuvant settings.

Monoclonal antibody treatment initially heralded an era of molecularly targeted therapy in oncology and is now widely applied in modulating anti-cancer immunity by targeting programmed cell receptors (PD-1, PD-L1), cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and, more recently, lymphocyte-activation gene 3 (LAG3). Chimeric antigen receptor T-cell therapy (CAR-T) recently proved to be a valid approach to inducing anti-cancer immunity by directly modifying the host’s immune cells. However, such cell-based therapy requires extensive resources such as leukapheresis, ex vivo modification and expansion of cytotoxic T-cells and current Good Manufacturing Practice (cGMP) laboratories and presents significant logistical challenges. Bi-/trispecific antibody technology is a novel pharmaceutical approach to facilitate the engagement of effector immune cells to potentially multiple cancer epitopes, e.g., the recently approved blinatumomab. This opens the opportunity to develop ‘off-the-shelf’ anti-cancer agents that achieve similar and/or complementary anti-cancer effects as those of modified immune cell therapy. The majority of bi-/trispecific antibodies target the tumor-associated antigens (TAA) located on the extracellular surface of cancer cells. The extracellular antigens represent just a small percentage of known TAAs and are often associated with higher toxicities because some of them are expressed on normal cells (off-target toxicity). In contrast, the targeting of intracellular TAAs such as mutant RAS and TP53 may lead to fewer off-target toxicities while still achieving the desired antitumor efficacy (on-target toxicity). Here, we provide a comprehensive review on the emerging field of bi-/tri-specific T-cell engagers and potential therapeutic opportunities.

Abstract Purpose: This phase Ib/2 trial investigated pembrolizumab-containing trimodality therapy in patients with gastroesophageal junction (GEJ) adenocarcinoma. Patients and Methods: Patients with GEJ adenocarcinoma (cT1–3NanyM0) received neoadjuvant pembrolizumab-containing chemoradiation (CROSS regimen) followed by surgical resection and adjuvant pembrolizumab. The primary endpoints were tolerability in the first 16 patients and pathologic complete response [pCR (ypT0N0)]. Secondary endpoints included progression-free survival (PFS) and overall survival (OS). An independent propensity-score-matched cohort (treated with CROSS without immunotherapy) was used for comparison. Exploratory analyses included immune biomarkers in the tumor microenvironment (TME) and plasma. Results: We enrolled 31 eligible patients, of whom 29 received all expected doses of neoadjuvant pembrolizumab and 28 underwent R0 resection. Safety endpoints were met. The primary efficacy endpoint was not met [7/31 (22.6%) achieved pCR]. Patients with high [i.e., combined positive score (CPS) ≥ 10] baseline expression of programmed death (PD)-L1 in the TME had a significantly higher pCR rate than those with low expression [50.0% (4/8) vs. 13.6% (3/22); P = 0.046]. Patients with high PD-L1 expression also experienced longer PFS and OS than propensity-score-matched patients. Among trial patients with PD-L1 CPS < 10, unprespecified analysis explored whether extracellular vesicles (EV) could identify further responders: an elevated plasma level of PD-L1–expressing EVs was significantly associated with higher pCR. Conclusions: Adding pembrolizumab to trimodality therapy showed acceptable tolerability but did not meet the pre-specified pCR endpoint. Exploratory analyses suggested that high PD-L1 expression in the TME and/or on EVs may identify patients most likely to achieve tumor response.

PURPOSECholangiocarcinomas (CCA) are a group of heterogeneous tumors arising from the biliary epithelia. Significant sequencing efforts have provided further insights into the molecular mechanisms of this disease including fibroblast growth factor receptor ( FGFR) alterations, which occurs in approximately 15%-20% of intrahepatic CCAs. Herein, we describe the FGFR inhibitor (FGFRi)-associated treatment toxicity and cancer-specific outcomes from a multicenter single-institution cohort.METHODSThis is a retrospective study of patients with CCA and known FGFR alterations treated with FGFRi. We describe the toxicity and efficacy in patients treated at Mayo Clinic between January 2010 and December 2020.RESULTSOur group identified 61 patients with advanced or metastatic CCA, 19 males (31%) and 42 females (69%), harboring FGFR alterations who received FGFRi. The most common grade 1 or higher adverse events for all patients included fatigue (92%), AST elevations (78%), anemia (80%), decreased platelet count (63%), and hyperphosphatemia (74%). Median progression-free survival on FGFRi was 5.8 months for all patients (95% CI, 4.9 to 9.0). Females had significantly longer progression-free survival at 6.9 months (95% CI, 5.2 to 11.8) on FGFRi compared with males at 4.9 months (95% CI, 2.8 to not estimable; P = .038).CONCLUSIONFGFRi are well tolerated with clinical efficacy. With the recent approval of FGFRi by the US Food and Drug Administration and ongoing clinical trials for new FGFRi, understanding outcomes and toxicity associated with these medications is important for precision oncology.