The evolving role of catumaxomab in gastric cancer

Targeted biopharmaceuticals for cancer treatment

Cancer is a complex invasive genetic disease that causes significant mortality rate worldwide. Protein-based biopharmaceuticals have significantly extended the lives of millions of cancer patients. This article reviews the biological function and application of targeted anticancer biopharmaceuticals. We first discuss the specific antigens and core pathways that are used in the development of targeted cancer therapy. The innovative monoclonal antibodies, non-antibody proteins, and small molecules targeting these antigens or pathways are then reviewed. Finally, the current challenges in anticancer biopharmaceuticals development and the potential solutions to address these challenges are discussed.

Is preoperative chemotherapy followed by surgery the appropriate treatment for signet ring cell containing adenocarcinomas of the esophagogastric junction and stomach?

BACKGROUND

Recent data suggest primary resection as the preferable approach in patients with signet ring cell gastric cancer (SRC). The aim of our retrospective exploratory study was to evaluate the influence of SRC on prognosis and response in esophagogastric adenocarcinoma treated with neoadjuvant chemotherapy.

METHODS

A total of 723 locally advanced esophagogastric adenocarcinomas (cT3/4 N any) documented in a prospective database from two academic centers were classified according to the WHO definition for SRC (more than 50 % SRC) and analyzed for their association with response and prognosis after neoadjuvant treatment.

RESULTS

A total of 235 tumors (32.5 %) contained SRC. Median survival of SRC was 26.3 compared with 46.6 months (p < 0.001) for non-SRC. SRC were significantly associated with female gender, gastric localization, advanced ypT and R1/2 categories, and lower risk of surgical complications and anastomotic leakage (each p < 0.001). Clinical (21.1 vs. 33.7 %, p = 0.001) and histopathological response (less than 10 % residual tumor: 16.3 vs. 28.9 %, p < 0.001) were significantly less frequent in SRC. Clinical response (p = 0.003) and complete histopathological response (pCR) (3.4 %) (p = 0.003) were associated with improved prognosis in SRC. Clinical response, surgical complications, ypTN categories, but not SRC were independent prognostic factors in forward Cox regression analysis in R0 resected patients. Risk of peritoneal carcinomatosis was increased (p < 0.001), while local (p = 0.015) and distant metastases (p = 0.02) were less frequent than in non-SRC.

CONCLUSIONS

Prognosis of SRC is unfavorable. Although response to neoadjuvant chemotherapy is rare in SRC, it is associated with improved outcome. Thus, chemotherapy might not generally be abandoned in SRC. A stratification based on SRC should be included in clinical trials.

Medikamentöse Therapie der Peritonealkarzinose

<b><i>Hintergrund:</i></b> Die Behandlung der Peritonealkarzinose ist eine interdisziplinäre medizinische Herausforderung. Betreffend der medikamentösen Therapie fehlt bislang eine Standardisierung. <b><i>Methode:</i></b> Relevante Artikel zum Thema Peritonealkarzinose aus den Datenbanken der U.S. National Library of Medicine (PubMed) sowie der Kongressregister der American Society of Clinical Oncology und der European Society of Medical Oncology wurden durchsucht. Die Bedeutung der Berichte für die klinische Praxis wurde zwischen den Autoren diskutiert und interdisziplinär abgestimmt. Es wurden praxisnahe Folgerungen und Empfehlungen abgeleitet. <b><i>Ergebnisse:</i></b> PubMed weist eine ansteigende Zahl an Publikationen zum Thema Peritonealkarzinose auf. In 2012 wurden 563 Arbeiten unter dem Stichwort abgelegt. Die medikamentöse Therapie der Peritonealkarzinose ist ein Teil der multimodalen Behandlung, zu der die lokalen chirurgischen und physikalischen Therapiemaßnahmen zählen. Die Auswahl der Chemotherapeutika richtet sich nach der entsprechenden malignen Grunderkrankung. Aktuelle zielgerichtete Ansätze wie die anti-angiogene Therapie und die gegen das epitheliale Zelladhäsionsmolekül (EpCAM) gerichtete Immuntherapie ergänzen neuerdings das Behandlungsspektrum bei Peritonealkarzinose und malignem Aszites. <b><i>Schlussfolgerungen:</i></b> Die medikamentöse Behandlung der Peritonealkarzinose bleibt eine medizinische Herausforderung. Die zunehmende Zahl an Publikationen und Studien auf dem Gebiet lässt aber mittlerweile mehr evidenzbasierte Entscheidungen zu. Die interdisziplinäre Abstimmung eines individuellen Behandlungskonzepts bleibt bis auf Weiteres der Goldstandard auch für die medikamentöse Therapie der Peritonealkarzinose.

[Gastric cancer and adenocarcinoma of the esophagogastric junction: principles of neoadjuvant therapy]

According to the current European and German S3 guidelines, neoadjuvant chemotherapy is now an integral part of the treatment of locally advanced gastric cancer and adenocarcinoma of the esophagogastric junction. Neoadjuvant therapy seeks to achieve downsizing of the primary tumor, lowering of the T and N categories and eradication of micrometastases. As the indications for neoadjuvant treatment are based on pretherapeutic information alone, a sophisticated clinical staging plays a central role. Despite all progress made in the field of diagnostic work-up, clinical staging often fails. Despite this fact, controlled randomized trials showed that neoadjuvant chemotherapy enhances the rate of curative (R0) resections and reduces the likelihood of systemic relapse. Overall, survival can be improved by neoadjuvant chemotherapy. The current research is focused on the molecular prediction of response and early response monitoring with functional imaging. New targeted drugs are being integrated into the peri-operative treatment.

Intraperitoneal treatment with the trifunctional bispecific antibody Catumaxomab in patients with platinum-resistant epithelial ovarian cancer: a phase IIa study of the AGO Study Group

OBJECTIVE

The aim of this study was to select the best catumaxomab regimen for further investigation in ovarian cancer based on confirmed tumour response.

METHODS

Randomised open-label phase IIa study in women with platinum-resistant or -refractory epithelial ovarian cancer. Catumaxomab (6-hour intraperitoneal infusion on days 0, 3, 7 and 10) was administered at a low (10, 10, 10 and 10 μg) or high dose (10, 20, 50 and 100 μg). Responders were patients with either a complete (CR) or partial (PR) response.

RESULTS

Forty-five patients were randomised to receive either low dose (23) or high dose (22). There were no responders in the low-dose versus one patient (5%) in the high-dose group with a PR. In the low-dose group, two patients (9%) had stable disease compared with five patients (23%) in the high-dose group. Catumaxomab was well tolerated and there was no difference between the dose groups in the incidence of treatment-induced adverse events, the most common of which were gastrointestinal and injection-site reactions.

CONCLUSION

Catumaxomab had modest activity in platinum-resistant ovarian cancer. The high-dose regimen was associated with a slightly better therapeutic index than the low dose regimen.

Assessing clinical benefit response in the treatment of gastric malignant ascites with non-measurable lesions: a multicenter phase II trial of paclitaxel for malignant ascites secondary to advanced/recurrent gastric cancer

BACKGROUND

Paclitaxel has shown promise against advanced gastric cancer and associated malignant ascites with non-measurable lesions. In order to evaluate the therapeutic effect of paclitaxel against malignant gastric ascites, a prospective phase II clinical trial was designed according to our previously proposed criteria represented by the clinical benefit response in gastric cancer (CBR-GC) criteria and the five-point method (5PM).

METHODS

Patients with advanced gastric cancer with malignant ascites were treated with 1-h intravenous (i.v.) infusions of 80 mg/m² of paclitaxel weekly over a 3-week cycle on days 1, 8, and 15, followed by 1 week of rest. Therapeutic responses were measured according to the CBR-GC criteria and the 5PM.

RESULTS

The CBR-GC criteria showed improved ascites volume and functional status in 39.1% of patients. A positive CBR-GC response in abdominal girth was seen in 31.3% of patients, and this was significantly correlated with the 5PM-estimated change in ascites volume (p < 0.001). The median number of treatment cycles was 3 (range 1-12). The most common non-hematological toxicity was anorexia, in 22.2% of patients.

CONCLUSION

Weekly i.v. paclitaxel is a safe and effective chemotherapeutic regimen based on validated CBR-CG criteria.

Efficacy of catumaxomab in tumor spheroid killing is mediated by its trifunctional mode of action

Catumaxomab is an intact trifunctional bispecific antibody targeting human EpCAM (epithelial cell adhesion molecule) and CD3 with further binding to Fcgamma receptor type I, IIa and III. We choose multicellular tumor spheroids (MCTS) of human EpCAM-positive FaDu tumor cells in co-culture with human peripheral blood mononuclear cells as an adequate three-dimensional in vitro model for pharmacological testing of catumaxomab. We found a strong dose-dependent antitumor response mediated by catumaxomab, with volume-decreased or completely destroyed tumor spheroids together with a massive immune cell infiltration and decreased signals for cancer cell viability and clonogenicity. In control experiments with F(ab')2 fragments of catumaxomab and the parental antibodies alone or in combination the effects in spheroid volume reduction were less than that of catumaxomab. All binding partners of the postulated tricell complex have to be present to exert catumaxomab's full mode of action. These distinct effects of catumaxomab are based on the unique composition of the trifunctional bispecific antibody. Since, in general, many cancers are treated by chemotherapy in combination with immunological tumor therapy, we additionally analyzed the effects of cisplatin alone and in combination with catumaxomab. For cisplatin alone we detected a dose-dependent response relating to decrease of spheroid volume. The combined approach resulted in a synergistic spheroid volume decrease and the colony formation was reduced to non-detectable levels.

Advanced gastric cancer--slow but steady progress

Progress in gastric cancer has been slow, but steady. Historically, patients commonly presented with significant disease related co-morbidity and received treatment of marginal benefit but unfortunately associated with significant toxicity. Today there is no universally accepted reference standard chemotherapy for this disease. However, there is reason for optimism. Meta-analyses of randomized trials have shown a benefit for first-line combination chemotherapy. Current three drug chemotherapy regimens remain toxic, though perhaps less so than previously, and can result in a small but significant survival advantage in carefully chosen patients. Incremental improvements have been observed in both treatment-related toxicity and survival after first-line therapy. More patients are candidates for chemotherapy beyond progression with first-line therapy and response rates with second-line regimens are similar to those seen in other solid tumor malignancies. Although there is no randomized data to support its use second-line treatment should be considered in appropriate patients. Even before the integration of targeted therapies in the treatment of gastric cancer, it was evident that survival for more than 2 years is possible in a subset of patients and large retrospective studies have highlighted clinicopathologic factors associated with improved survival. Presently, with the addition of targeted therapy, especially anti-angiogenic and anti-Her2 therapy, and a better understanding of the biology of the disease, perhaps a sense of optimism should indeed suppress the nihilism commonly associated with this disease.

[Principles of neoadjuvant therapy]

Neoadjuvant therapy is now an integral part in the treatment of locally advanced cancer of the esophagus and stomach. The mechanisms of action comprise downsizing of the primary tumor, improvement of the T and N categories and the earliest possible eradication of micrometastases. Several controlled clinical studies could show that these principles can indeed augment the rate of curative (R0) resections and can reduce the likelihood of systemic recurrences. As a consequence overall survival is improved by neoadjuvant therapy. This article summarizes how the basic principles of neoadjuvant therapy translate into clinical practice and gives a review of current developmental perspectives in this field.