Hiroto Ueda

HER2 genomic amplification in circulating tumor DNA from patients with cetuximab-resistant colorectal cancer

Background Patients with metastatic colorectal cancer (mCRC) harboring wild-type KRAS benefit from epidermal growth factor receptor (EGFR)-targeted therapy. However, patients who are treated with anti-EGFR antibodies will eventually develop the resistance to those agents. HER2 amplification is one of the mechanisms conferring resistance to anti-EGFR antibody therapy and could therefore be a potential therapeutic target. The aim of this study was to detect HER2 amplification in circulating tumor DNA (ctDNA) from patients with CRC and acquired resistance to anti-EGFR antibody therapy. Results Our data showed that 22% (4/18) of patients in the cohort exhibited HER2 amplification. One of these patients was found to be positive for HER2 amplification in matched tumor specimens collected after cetuximab therapy, at which point the patient had acquired cetuximab resistance, despite being negative for HER2 amplification prior to therapy. Methods We analyzed plasma ctDNA using digital polymerase chain reaction (PCR) from 18 patients with CRC, who had been treated with anti-EGFR antibody-based therapy (cetuximab) and subsequently acquired resistant cetuximab. HER2 gene copy number was analyzed using fluorescence in situ hybridization in tumor samples before and after acquisition of resistance to cetuximab-based therapy. Conclusion Analysis of plasma ctDNA by digital PCR could be useful for detecting HER2 amplification in patients with CRC who were resistant to anti-EGFR antibody therapy.

Heregulin-expressing HER2-positive breast and gastric cancer exhibited heterogeneous susceptibility to the anti-HER2 agents lapatinib, trastuzumab and T-DM1

Background Overexpression of heregulin, a HER3 ligand, is one mechanism that confers resistance to the anti-HER2 agents trastuzumab and lapatinib. We investigated the impact of heregulin expression on the efficacy of HER2-targeted therapeutic agents, including trastuzumab, trastuzumab emtansine (T-DM1) and lapatinib, in vitro and in vivo and evaluated the heregulin messenger RNA (mRNA) levels in specimens from patients with HER2-positive breast or gastric cancer. Results Cell proliferation and apoptosis assays demonstrated that heregulin conferred robust resistance to lapatinib and trastuzumab via HER3-Akt pathway activation followed by survivin overexpression; however, heregulin conferred minimal or no resistance to T-DM1 and paclitaxel. The heregulin mRNA level of one of 10 patients was up-regulated after the acquisition of resistance to trastuzumab-based therapy. Materials and Methods SK-BR-3, NCI-N87, BT-474, MDA-MB-453, HCC1954, SNU-216 and 4-1ST cells were pharmacologically treated with recombinant heregulin or transfected with the heregulin gene. We also assessed the expression of heregulin mRNA in HER2-positive breast or gastric cancer samples before and after trastuzumab-based therapy using a RT-PCR-based method. Conclusions mRNA up-regulation of heregulin was observed in clinical breast cancer specimens during trastuzumab-based treatment, but heregulin overexpression had a limited effect on the sensitivity to T-DM1 in vitro and in vivo.

Combined Analysis of Plasma Amphiregulin and Heregulin Predicts Response to Cetuximab in Metastatic Colorectal Cancer

Background Amphiregulin, a ligand of the epidermal growth factor receptor (EGFR), is associated with the efficacy of cetuximab, an antibody against EGFR, as treatment for colorectal cancer (CRC). In contrast, the HER3 ligand heregulin correlates with cetuximab resistance. In this study, we evaluated how the combined levels of circulating amphiregulin and heregulin affect clinical outcomes in patients who receive cetuximab as therapy against advanced CRC. Methods Plasma levels of amphiregulin and heregulin were measured by enzyme-linked immunosorbent assay in 50 patients with CRC in a training cohort, and in 10 patients in a validation cohort. The combined expression was then assessed with clinical outcome after receiver operating characteristics analysis. Results Overall response rate was 26%, and median progression-free survival was 110 days in the training cohort. Patients with high amphiregulin and low heregulin had significantly higher objective response rate at 58% and significantly longer progression-free survival of 216 days. This result was confirmed in the validation cohort. Conclusion A subgroup of CRC patients with high amphiregulin and low heregulin respond to cetuximab therapy better than other patients.

Clinical evaluation of palliative chemoradiotherapy for metastatic esophageal cancer

Platinum-based chemotherapy is considered a standard treatment option for patients with metastatic esophageal carcinoma. However, the overall survival of patients receiving such treatment is <1 year. A common presenting symptom of esophageal cancer is dysphagia, which has a substantial impact on quality of life. We have now retrospectively evaluated the efficacy and safety of palliative chemoradiotherapy for patients with stage IV esophageal cancer, most of whom are unfit for curative chemoradiotherapy. Fifty consecutive patients diagnosed with stage IV esophageal cancer were treated with concurrent chemoradiotherapy at Kindai University Hospital between April 2008 and December 2014. Most (90%) patients received a total radiation dose of at least 50 Gy, and the median number of treatment cycles per patient was four for the combination of 5-fluorouracil and cisplatin. The response of the primary tumor and the overall response were 80% and 44%, respectively. The dysphagia score was improved after chemoradiotherapy in 36 (72%) patients and did not change between before and after treatment in 14 (28%) patients. With a median follow-up time of 9.4 months from the start of chemoradiotherapy, the median progression-free survival and overall survival were 4.7 and 12.3 months, respectively. Three patients (T4b in two, T3 in one) developed esophagobronchial fistula after completion of chemoradiotherapy (n = 2) or after disease progression (n = 1), resulting in death in each case. Our results suggest that palliative chemoradioiotherapy was safe and contributed the improvement of dysphagia in patients with stage IV esophageal cancer.Platinum-based chemotherapy is considered a standard treatment option for patients with metastatic esophageal carcinoma. However, the overall survival of patients receiving such treatment is <1 year. A common presenting symptom of esophageal cancer is dysphagia, which has a substantial impact on quality of life. We have now retrospectively evaluated the efficacy and safety of palliative chemoradiotherapy for patients with stage IV esophageal cancer, most of whom are unfit for curative chemoradiotherapy. Fifty consecutive patients diagnosed with stage IV esophageal cancer were treated with concurrent chemoradiotherapy at Kindai University Hospital between April 2008 and December 2014. Most (90%) patients received a total radiation dose of at least 50 Gy, and the median number of treatment cycles per patient was four for the combination of 5-fluorouracil and cisplatin. The response of the primary tumor and the overall response were 80% and 44%, respectively. The dysphagia score was improved after chemoradiotherapy in 36 (72%) patients and did not change between before and after treatment in 14 (28%) patients. With a median follow-up time of 9.4 months from the start of chemoradiotherapy, the median progression-free survival and overall survival were 4.7 and 12.3 months, respectively. Three patients (T4b in two, T3 in one) developed esophagobronchial fistula after completion of chemoradiotherapy (n = 2) or after disease progression (n = 1), resulting in death in each case. Our results suggest that palliative chemoradioiotherapy was safe and contributed the improvement of dysphagia in patients with stage IV esophageal cancer.

Phase II Trial of 5‐Fluorouracil, Docetaxel, and Nedaplatin (UDON) Combination Therapy for Recurrent or Metastatic Esophageal Cancer

Lessons Learned. The 5‐fluorouracil, docetaxel, and nedaplatin (UDON) regimen was well tolerated and showed promising antitumor activity in terms of both objective response rate and survival for patients with advanced or recurrent esophageal squamous cell carcinoma in the first‐line setting. UDON may be an optimal treatment option for patients with advanced esophageal cancer who are unfit for docetaxel, cisplatin, and 5‐fluorouracil regimens. The high response rate as well as the rapid and marked tumor shrinkage associated with UDON suggest that further evaluation of this regimen in the neoadjuvant setting is warranted. Background. A phase II study was performed to evaluate the efficacy and safety of 5‐fluorouracil (5‐FU), docetaxel, and nedaplatin (UDON) combination therapy for untreated recurrent or metastatic esophageal cancer. Methods. Patients received intravenous nedaplatin (90 mg/m2) on day 1, docetaxel (35 mg/m2) on days 1 and 15, and 5‐fluorouracil (800 mg/m2) on days 1–5 of a 4‐week cycle. The primary endpoint was response rate, with secondary endpoints including overall survival (OS), progression‐free survival (PFS), dysphagia score, and adverse events. Results. Between March 2015 and July 2017, 23 patients were enrolled. Of 22 evaluable patients, 16 and 4 individuals experienced a partial response and stable disease, respectively, yielding a response rate of 72.7% (95% confidence interval [CI], 49.8%–89.3%) and disease control rate of 90.9% (95% CI, 70.8%–98.9%). Median OS and PFS were 11.2 months (95% CI, 9.1 months to not reached) and 6.0 months (95% CI, 2.5–10.6 months), respectively. Eleven (64.7%) of the 17 patients with a primary lesion showed amelioration of dysphagia after treatment. Frequent adverse events of grade 3 or 4 included neutropenia (87.0%) and leukopenia (39.1%). Febrile neutropenia was observed in two patients (8.7%). Conclusion. This phase II study demonstrated promising antitumor activity and good tolerability of UDON.

Abstract 2939: Heregulin-induced resistance against HER2-targeted therapies in HER2 positive breast and gastric cancer in vitro and in vivo

Background HER2-targeted therapies have been shown clinical benefits in patients with HER2 positive breast and gastric cancers. However, resistance against such targeted therapies eventually develops in most cases. Overexpression of heregulin, a ligand for HER3, has been reported as one of the resistant mechanism against HER2-targeted therapies. Upregulation of heregulin activates HER3-PI3K-AKT signaling, leading to the resistance against HER2-targeted therapies. We investigated the effects of heregulin in cell lines and evaluate its clinical impacts in HER2 positive breast and gastric cancers. Materials and methods We utilized transfected or recombinant heregulin to investigate the effect of heregulin on proliferation and apoptosis of SK-BR-3 and NCI-N87 cell lines treated with lapatinib, trastuzumab, trastuzumab-emtansine and paclitaxel. Clinical data and specimens were obtained from patients with HER2 positive breast and gastric cancers, evaluating their heregulin value from both serum and tissues using ELISA and RT-PCR, respectively. Results Heregulin transfection and recombinant heregulin conferred resistance against treatment with lapatinib, trastuzumab, and weak resistance against trastuzumab-emtansine, but no resistance against paclitaxel in HER2 positive cell lines. Clinical data of heregulin among patients treated with HER2-targeted therapies revealed that patients with relatively high heregulin value tended to have worse prognosis. Conclusions Together these data, overexpression of heregulin may at least in part play a role in resistance against HER2-targeted therapies in HER2 positive cancer patients. Further investigation is warranted to elucidate the relevance of treatments targeting heregulin-HER3-PI3K signaling. Citation Format: Yoshikane Nonagase, Kimio Yonesaka, Satomi Watanabe, Koji Haratani, Takayuki Takahama, Naoki Takegawa, Hiroto Ueda, Hisato Kawakami, Hidetoshi Hayashi, Masayuki Takeda, Haruka Sakamoto, Takao Tamura, Kazuhiko Nakagawa, Junji Tsurutani. Heregulin-induced resistance against HER2-targeted therapies in HER2 positive breast and gastric cancer in vitro and in vivo. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2939.