Regression of liver metastases after treatment with intraperitoneal catumaxomab for malignant ascites due to breast cancer

Randomised phase II trial to investigate catumaxomab (anti-EpCAM × anti-CD3) for treatment of peritoneal carcinomatosis in patients with gastric cancer

BACKGROUND

Peritoneal carcinomatosis (PC) represents an unfavourable prognostic factor for patients with gastric cancer (GC). Intraperitoneal treatment with the bispecific and trifunctional antibody catumaxomab (EpCAM, CD3), in addition to systemic chemotherapy, could improve elimination of PC.

METHODS

This prospective, randomised, phase II study investigated the efficacy of catumaxomab followed by chemotherapy (arm A, 5-fluorouracil, leucovorin, oxaliplatin, docetaxel, FLOT) or FLOT alone (arm B) in patients with GC and PC. Primary endpoint was the rate of macroscopic complete remission (mCR) of PC at the time of second diagnostic laparoscopy/laparotomy prior to optional surgery.

RESULTS

Median follow-up was 52 months. Out of 35 patients screened, 15 were allocated to arm A and 16 to arm B. mCR rate was 27% in arm A and 19% in arm B (p = 0.69). Severe side effects associated with catumaxomab were nausea, infection, abdominal pain, and elevated liver enzymes. Median progression-free (6.7 vs. 5.4 months, p = 0.71) and overall survival (13.2 vs. 13.0 months, p = 0.97) were not significantly different in both treatment arms.

CONCLUSIONS

Addition of catumaxomab to systemic chemotherapy was feasible and tolerable in advanced GC. Although the primary endpoint could not be demonstrated, results are promising for future investigations integrating intraperitoneal immunotherapy into a multimodal treatment strategy.

Tetraspecific scFv construct provides NK cell mediated ADCC and self-sustaining stimuli via insertion of IL-15 as a cross-linker

BACKGROUND

The design of a highly effective anti-cancer immune-engager would include targeting of highly drug refractory cancer stem cells (CSC). The design would promote effective antibody-dependent cell-mediated cytotoxicity (ADCC) and simultaneously promote costimulation to expand and self-sustain the effector NK cell population. Based on our bispecific NK cell engager platform we constructed a tetraspecific killer engager (TetraKE) comprising single-chain variable fragments (scFvs) binding FcγRIII (CD16) on NK cells, EpCAM on carcinoma cells and CD133 on cancer stem cells in order to promote ADCC. Furthermore, an Interleukin (IL)-15-crosslinker enhanced NK cell related proliferation resulting in a highly active drug termed 1615EpCAM133.

RESULTS

Proliferation assays showed TetraKE promoted proliferation and enhanced NK cell survival. Drug-target binding, NK cell related degranulation, and IFN-γ production was specific for both tumor related antigens in EpCAM and CD133 bearing cancer cell lines. The TetraKE showed higher killing activity and superior dose dependent degranulation. Cytokine profiling showed a moderately enhanced IFN-γ production, enhanced GM-CSF production, but no evidence of induction of excessive cytokine release.

METHODS

Assembly and synthesis of hybrid genes encoding the TetraKE were performed using DNA shuffling and ligation. The TetraKE was tested for efficacy, specificity, proliferation, survival, and cytokine production using carcinoma cell lines and functional assays measuring NK cell activity.

CONCLUSION

1615EpCAM133 combines improved induction of ADCC with enhanced proliferation, limited cytokine response, and prolonged survival and proliferation of NK cells. By linking scFv-related targeting of carcinoma and CSCs with a sustaining IL-15 signal, our new construct shows great promise to target cancer and CSCs.

Immunotherapy of hepatocellular carcinoma using chimeric antigen receptors and bispecific antibodies

Hepatocellular carcinoma (HCC) is one of the most lethal cancers worldwide with an overall survival rate of less than 15% in developed countries. Despite attempts at new therapeutic strategies, the majority of patients succumb to this cancer. Buttressed by the highly successful clinical impact in melanoma, immunotherapy is gaining momentum as the next treatment modality for many human cancers. Chimeric antigen receptors (CAR) contain the antigen binding moieties of a monoclonal antibody and the co-stimulatory and signaling domains associated with effector receptor signaling. Bispecific antibodies (BsAb) combine the binding specificities of two different monoclonal antibodies, one activating a receptor on a killer effector cell, while the other engaging a tumor-associated antigen to initiate tumor cytotoxicity. In this review, we survey the HCC targets for which CARs and bispecific antibodies have been generated. The pros and cons of these targets for T-cell and Natural Killer cell based immunotherapy will be discussed.

Enhanced ADCC and NK Cell Activation of an Anticarcinoma Bispecific Antibody by Genetic Insertion of a Modified IL-15 Cross-linker

Previously, we constructed a bispecific NK-cell-engager (BiKE) bearing single-chain variable fragments (scFv) against CD16 on NK cells and EpCAM on tumor cells. This BiKE facilitated antigen-specific antibody-dependent cell-mediated cytotoxicity (ADCC) but did not induce NK cell expansion. We incorporated a modified interleukin-15 cross-linker to create a trispecific construct (TriKE) in order to improve activation, proliferation, and survival of NK cells. Synthesis and assembly of hybrid genes encoding the TriKE was accomplished using DNA-shuffling and DNA-ligation techniques. The TriKE was tested for specificity, efficacy, proliferative capability, and cytokine profile using functional assays. The molecular modifications improved yield without compromising binding to EpCAM(+) HT-29 colorectal carcinoma cells. (51)Chromium-release and degranulation assays showed better killing rates with TriKE compared to BiKE. TriKE was more active in a variety of different carcinoma cell lines. TriKE showed the ability to stimulate expansion of CD56(+)CD3(-) NK cells. BiKE and TriKE showed enhanced but not supraphysiologic levels of cytokine secretion. 1615EpCAM TriKE drives enhanced ADCC while significantly improving proliferation, activation, and survival of NK cell effectors. The TriKE provides a selectively delivered self-sustaining signal at the NK/tumor cell synapse. Targeted cytokine stimulation, rather than systemic cytokine administration, may impact toxicity in patients rendering the TriKE a promising new off-the-shelf carcinoma therapy.

Outpatient Intraperitoneal Catumaxomab Therapy for Malignant Ascites Related to Advanced Gynecologic Neoplasms

BACKGROUND

Catumaxomab (CATU) is a trifunctional antibody approved for intraperitoneal (i.p.) treatment of malignant ascites (MA) related to carcinomas expressing the epithelial cell-adhesion molecule (EpCAM). CATU is mostly given to hospitalized patients, although outpatient treatment seems appropriate in selected individuals. This observational trial sought to obtain more detailed information regarding the feasibility of CATU in outpatients with MA related to various gynecologic tumors, including epithelial ovarian (EOC) and metastatic breast cancer (MBC).

MATERIALS AND METHODS

A total of 30 patients were included, 17 with EOC, 7 with MBC, and 6 with other malignancies. The patients had failed a median of 5 (range 1-12) previous systemic treatments. CATU was administered via an indwelling i.p. catheter at four increasing doses (i.e., 10, 20, 50, and 150 µg) given at 4-day intervals over 2 weeks. Toxicities were scored according to the Common Terminology Criteria for Adverse Events, version 4.03. Puncture-free survival (PuFS) was calculated from the start of CATU until the next puncture for MA, death, or loss to follow-up. Overall survival (OS) was calculated from the start of CATU to death from any reason or loss to follow-up. We also investigated various clinical parameters to predict PuFS and OS. These included age, tumor type, performance status, intensity of pretreatment, presence of extraperitoneal metastases, relative lymphocyte count at baseline, patient adherence to therapy, and the patients' ability to undergo systemic treatment after CATU.

RESULTS

CATU was exclusively given on an outpatient basis, and 19 patients (63.3%) received all four planned i.p. instillations. Toxicity was the reason for discontinuation in only 2 patients. Toxicity was generally manageable, with abdominal pain, nausea/vomiting, fatigue, and fever the predominant adverse effects. Secondary hospitalization was necessary for 7 patients (23.3%), with a general deteriorated condition in 5 and fever/infection or abdominal pain in 1 patient each. Subsequent systemic treatment was possible in 11 patients (36.7%). Only 5 patients (16.7%) required a second puncture after i.p. CATU. The median PuFS was 56 days, and the median OS was 79.5 days. Positive predictors of both PuFS and OS were performance status, absence of extraperitoneal tumor, the capability to receive all four CATU infusions, and the ability to undergo subsequent systemic treatment.

CONCLUSION

Outpatient i.p. CATU therapy for MA related to various gynecologic carcinomas is safe and effective in producing good ascites control in most individuals, allowing for subsequent systemic therapy in a substantial proportion of patients.

IMPLICATIONS FOR PRACTICE

Intraperitoneal treatment with the trifunctional antibody catumaxomab (CATU) was possible in a selected population of 30 outpatients with malignant ascites due to epithelial female genital tract or breast carcinoma. Toxicity was largely manageable. Patients in good condition at baseline, without extraperitoneal tumor and/or liver metastases, and with the ability to complete all four planned CATU instillations and the capability of undergoing subsequent systemic therapy benefited the most in terms of both puncture-free and overall survival. Outpatient i.p. CATU is safe and effective in a selected group of patients with malignant ascites due to various gynecologic malignancies and could be cost-saving compared with an inpatient approach.

Multi-specific antibodies for cancer immunotherapy

Targeted treatment of cancer with monoclonal antibodies has added to the beneficial outcome of patients. In an attempt to improve anti-tumor activity of monoclonal antibodies, multi-specific antibodies have entered the research arena. To date, only a few multi-specific constructs have entered phase III clinical trials, in contrast to classical monoclonal antibodies, which are the standard first-line therapy in several tumor entities. In this review, we will assess selected multi-specific antibodies in pre-clinical and clinical development that may be new treatment options for cancer patients in the very near future. We will further evaluate therapy modalities including the timely distribution or the combination of various therapeutic approaches and assess the potential role of multi-specific antibodies in cancer treatment.

A phase I trial of intravenous catumaxomab: a bispecific monoclonal antibody targeting EpCAM and the T cell coreceptor CD3

PURPOSE

The aim of the study was to evaluate the safety and determine the maximum tolerated dose (MTD) of intravenous catumaxomab, a trifunctional bispecific antibody that binds to EpCAM on epithelial cancer cells and CD3 on T cells.

METHODS

The trial was a dose-escalation study with a 3 + 3 design in epithelial cancers with known EpCAM expression. The dose-limiting toxicity (DLT) period consisted of 4 weeks, with weekly intravenous administration of catumaxomab. Key DLTs were ≥grade 3 optimally treated non-hematological toxicity; ≥grade 3 infusion-related reactions refractory to supportive care; ≥grade 3 increase in liver enzymes and/or bilirubin not resolving to grade 2.

RESULTS

Sixteen patients were enrolled receiving doses of 2 (n = 5), 4 (n = 3), 7 (n = 7) and 10 µg catumaxomab (n = 1). The most common treatment-emergent adverse events (TEAEs) were chills (93.8 %) and pyrexia (87.5 %). The most common TEAE of grade ≥3 was transient dose-dependent increases in aspartate aminotransferase (56.3 %). The intensity of toxicities decreased with the number of infusions. Also, serum IL-6 increased in a dose-dependent manner and reverted to low or undetectable levels after four infusions. A reversible decrease in liver function test (prothrombin time) at the 7-µg dose level was considered a DLT. The first patient at 10 µg experienced a fatal hepatic failure related to catumaxomab that led to the termination of the study.

CONCLUSIONS

The MTD of weekly intravenous catumaxomab was 7 µg. Major toxicities were cytokine release-related symptoms and hepatotoxicity.

Bone marrow stromal antigen 2 expressed in cancer cells promotes mammary tumor growth and metastasis

Introduction

Several innate immunity genes are overexpressed in human cancers and their roles remain controversial. Bone marrow stromal antigen 2 (BST-2) is one such gene whose role in cancer is not clear. BST-2 is a unique innate immunity gene with both antiviral and pro-tumor functions and therefore can serve as a paradigm for understanding the roles of other innate immunity genes in cancers.

Methods

Meta-analysis of tumors from breast cancer patients obtained from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) datasets were evaluated for levels of BST-2 expression and for tumor aggressiveness. In vivo, we examined the effect of knockdown of BST-2 in two different murine carcinoma cells on tumor growth, metastasis, and survival. In vitro, we assessed the effect of carcinoma cell BST-2 knockdown and/or overexpression on adhesion, anchorage-independent growth, migration, and invasion.

Results

BST-2 in breast tumors and mammary cancer cells is a strong predictor of tumor size, tumor aggressiveness, and host survival. In humans, BST-2 mRNA is elevated in metastatic and invasive breast tumors. In mice, orthotopic implantation of mammary tumor cells lacking BST-2 increased tumor latency, decreased primary tumor growth, reduced metastases to distal organs, and prolonged host survival. Furthermore, we found that the cellular basis for the role of BST-2 in promoting tumorigenesis include BST-2-directed enhancement in cancer cell adhesion, anchorage-independency, migration, and invasion.

Conclusions

BST-2 contributes to the emergence of neoplasia and malignant progression of breast cancer. Thus, BST-2 may (1) serve as a biomarker for aggressive breast cancers, and (2) be a novel target for breast cancer therapeutics.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-014-0493-8) contains supplementary material, which is available to authorized users.

Treatment of malignant ascites with a second cycle of catumaxomab in gastric signet cell carcinoma--a report of 2 cases

BACKGROUND

Malignant ascites is a frequent complication in gastrointestinal malignancy and is unresponsive to systemic therapies. Therapeutic options are limited, and repeated paracentesis is associated with increased loss of fluids and proteins, and impaired quality of life. The bi-specific trifunctional antibody catumaxomab has been approved for the treatment of refractory ascites. It has been proposed that repeated application leads to formation of human anti-mouse antibodies with a decrease in effectiveness and potentially hypersensitivity reactions.

CASE REPORT

Here we report on the repeated application of catumaxomab in 2 patients with advanced signet cell gastric cancer. Repeated application was safe and effective in decreasing the frequency of paracentesis in 1 patient. No hypersensitivity reactions beyond the immune-mediated side effects were observed with the application of catumaxomab. 1 patient experienced an inflammatory response with acute deterioration of kidney function during the first cycle but recovered quickly. Re-challenge with catumaxomab did not produce an inflammatory reaction in the 2 cases.

CONCLUSION

Overall, the repeated treatment was associated with a beneficial effect on puncture-free survival in 1 patient, and appears to be a treatment option in selected patients with gastrointestinal malignancy.

Systemic effect of catumaxomab in a patient with metastasized colorectal cancer: a case report

BACKGROUND

Catumaxomab, the first anti-EpCAM antibody, was approved in 2009 for the treatment of malignant ascites in cancer patients with EpCAM positive tumors. We consider this case of interest as treatment with catumaxomab not only prolonged the puncture-free interval but also showed a systemic effect in a patient with metastasized colorectal cancer by regression of a pulmonary metastasis.

CASE PRESENTATION

We describe the case of a 78 year old patient initially diagnosed with locally advanced colon cancer and one synchronous liver metastasis in September 2010 who was treated by hemicolectomy and simultaneous atypical liver resection. During adjuvant chemotherapy the patient developed a peritoneal carcinomatosis with ascites in March 2011. Palliative chemotherapy was not well tolerated and therefore refused by the patient. Because of disease progression in June 2011 with one pulmonary metastasis and clinically predominant ascites an immunotherapy with intraperitoneal catumaxomab was started in December 2011. After treatment with catumaxomab a puncture free survival of 12 months as well as a regression of the pulmonary lesion was achieved until January 2013.

CONCLUSION

This case suggests that treatment with catumaxomab does not only improve quality of life by local suppression of malignant ascites but also might have a systemic antitumor effect.

The contribution of catumaxomab in the treatment of malignant ascites in patients with ovarian cancer: a review of the literature

The approval of the first specific drug catumaxomab for the treatment of malignant ascites is the subject of this review. This trifunctional antibody is known to kill EpCAM-positive tumor cells and therefore attacks the primary cause of malignant ascites formation in the peritoneal cavity. Until today catumaxomab is the only EpCam-targeted antibody approved by the European Medicines Agency. Ovarian cancer is caused by epithelial tumors cells which overexpress epithelial cell adhesion molecule (EpCAM). The existing literature concerning the use of catumaxomab for the treatment of malignant ascites associated with ovarian cancer until today is reported in this article. It is very encouraging that different prospective studies from diverse scientific teams recently presented positive results concerning the efficacy and the safety of catumaxomab in the treatment of malignant ascites in patients with ovarian cancer. A case of a patient with ovarian cancer FIGO IIIc is also referred in this article. A complete remission and stable disease was found after 4 i.p. infusions of catumaxomab.