Clinical Response to Futibatinib in Patients with High-Level FGFR2-Amplified Advanced Gastric Cancer: Two Case Reports

A case of treatment-resistant advanced gastric cancer with FGFR2 gene alteration successfully treated with pemigatinib

Comprehensive genome profiling (CGP) is expected to widen the scope of cancer drug options by identifying the genes involved in carcinogenesis. However, a few patients can access recommended treatments following CGP. Herein, we report a case in which pemigatinib, a selective fibroblast growth factor receptor (FGFR) inhibitor, was used as last-line therapy to treat a patient with advanced gastric cancer exhibiting FGFR2 genomic alterations, as determined by CGP testing. The patient (male, 52 years old) was diagnosed with advanced gastric cancer (cStage IV, cT4aN3M1 [LYM], por, HER2 0, microsatellite stable) and received docetaxel + cisplatin + S-1 (7 cycles), irinotecan + ramucirumab (11 cycles), and nivolumab (3 cycles), but experienced progressive disease (PD). Subsequently, FoundationOne Liquid CDx testing was conducted, revealing FGFR2 rearrangement and amplification; however, no clinical trials on genotype-matched therapies for FGFR2 alterations were available. After three cycles of TAS-102, the patient experienced PD and provided consent for the off-label use of pemigatinib. The Cancer Genomics Medical Committee of our hospital approved the self-funded treatment. The patient had markedly decreased CEA and CA19-9 levels after treatment initiation, but experienced PD after five courses. Over the treatment course, grade 1 hyperphosphatemia and onychomadesis were observed. To the best of our knowledge, this is the first reported case of pemigatinib therapy employed in a patient with advanced gastric cancer exhibiting FGFR2 gene alterations. This case could serve as a notable example of tumor-agnostic therapy to broaden treatment options for gastric cancer patients with rare genetic alterations.

Targeting FGFR Pathway Is Not an Effective Therapeutic Strategy in Patients with Unselected Metastatic Esophagogastric Cancer Resistant to Trastuzumab

Trastuzumab plus chemotherapy is the standard of care for the first-line treatment of patients with HER2+ advanced esophagogastric (EG) cancer. Nevertheless, patients frequently develop resistance. In preclinical models, we identified the overexpression of Fibroblast Growth Factor Receptor (FGFR) 3 as a mechanism potentially involved in trastuzumab-acquired resistance. FGFR inhibition could be a potential mechanism as a second-line treatment. In this Simon’s two-stage phase 2, single arm study, patients with advanced EG cancer refractory to trastuzumab-containing therapies received pemigatinib, an inhibitor of FGFR. The primary end point was the 12-week progression-free survival rate. Translational analyses were performed on tissue and plasma samples. Eight patients were enrolled in the first stage. Although the 6-week disease control rate was 25%, only one patient achieved a stable disease after 12 weeks of treatment. The trial was discontinued before the second stage. Two out of six evaluable tumor samples expressed FGFR3. No FGFRs amplification was detected. HER2 amplification was lost in three out of eight patients. Three patients had an high Tumor Mutational Burden, and two of them are significantly long-term survivors. These results do not support the therapeutic efficacy of targeting FGFR in unselected patients with advanced EG cancer, who are refractory to trastuzumab-containing therapies.

Patient Selection Approaches in FGFR Inhibitor Trials-Many Paths to the Same End?

Inhibitors of fibroblast growth factor receptor (FGFR) signaling have been investigated in various human cancer diseases. Recently, the first compounds received FDA approval in biomarker-selected patient populations. Different approaches and technologies have been applied in clinical trials, ranging from protein (immunohistochemistry) to mRNA expression (e.g., RNA in situ hybridization) and to detection of various DNA alterations (e.g., copy number variations, mutations, gene fusions). We review, here, the advantages and limitations of the different technologies and discuss the importance of tissue and disease context in identifying the best predictive biomarker for FGFR targeting therapies.

Tanshinone IIA May Inhibit Gastric Cancer via Affecting the Intestinal Microbiome

Background

Gastric cancer (GC) belongs to a type of the most deadly cancer in the world, and the incidence rate of GC will increase in the coming decades. Tanshinone IIA (Tan IIA) is an active component that separated from Danshen. Tan IIA may also exert its therapeutic effects in disease with intestinal dysbacteriosis, at least partially, via regulating the intestinal microbiome. Nevertheless, it is obscure whether Tanshinone IIA affects the intestinal dysbacteriosis and plays antitumor roles. This research was designed to explore Tanshinone IIA potential on the intestinal dysbacteriosis of GC xenograft mice.

Methods

Mouse xenograft GC tumor models were built and treated by Tan IIA. The tumor growth as well as microbiome in the intestinal were compared. Western blot was used to detect the phosphorylation of the NF-κB and expressions of the downstream cytokines IL-6 and IL-1β.

Results

Microbiome in the intestinal was changed in xenograft tumor mice in comparison with the control mice. What is more, Tan IIA could influence the microbiome in the intestinal of the tumor mice. Tan IIA hinders the growth of xenograft tumor and change the microbiome in the intestinal, but intestinal dysbacteriosis condition partially blocked Tan IIA-stimulated antitumor effects. In addition, intestinal dysbacteriosis abrogated Tan IIA-stimulated decrease in the NF-κB signaling in xenograft tumor mice.

Conclusions

Tanshinone IIA may inhibit GC tumor growth via affecting the intestinal microbiome through regulating the NF-κB signaling.