MUC1-positive Cancer Research Articles

Efficacy of MUC1-targeted CAR-NK cells against human tongue squamous cell carcinoma.

The clinical efficacy of CAR-NK cells against CD19-expressing blood cancers has been demonstrated, and they have shown potential for treating solid tumors as well. However, the efficacy of CAR-NK cells for treating human oral tongue squamous cell carcinoma (OTSCC) has not been examined. We assessed MUC1 expression in human OTSCC tissue and a cell line using immunohistochemistry and immunofluorescence. We constructed NK cells that express CAR targeted to MUC1 from pluripotent stem cells (iPSC-derived MUC1-targeted CAR-NK cells) and evaluated their effectiveness against OTSCC in vitro using the xCELLigence Real-Time Cell Analysis system and CCK8 assay, and in vivo by measuring xenograft growth daily in BNDG mice treated with MUC1-targeted CAR-NK cells. As controls, we used iPSC-derived NK cells and NK-free media, which were CAR-free and blank, respectively. MUC1 expression was detected in 79.5% (66/83) of all OTSCC patients and 72.7% (24/33) of stage III and IV. In stage III and IV MUC1 positive OTSCC, 63.6% (21/33) and 48.5% (16/33) patients had a MUC1-positive cancer cell rate of more than 50% and 80%, respectively. The iPSC-derived MUC1-targeted CAR-NK cells exhibited significant cytotoxicity against MUC1-expressing OTSCC cells in vitro, in a time- and dose-dependent manner, and showed a significant inhibitory effect on xenograft growth compared to both the iPSC-derived NK cells and the blank controls. We observed no weight loss, severe hematological toxicity or NK cell-mediated death in the BNDG mice. The MUC1-targeted CAR-NK cells had significant efficacy against human OTSCC, and their promising therapeutic response warrants further clinical trials.

Suppression of MUC1-Overexpressing Tumors by a Novel MUC1/CD3 Bispecific Antibody.

Mucin1 (MUC1) is abnormally glycosylated and overexpressed in a variety of epithelial cancers and plays a critical role in tumor progression. MUC1 has received remark attention as an oncogenic molecule and is considered a valuable tumor target for immunotherapy, while many monoclonal antibodies (mAbs) targeting MUC1-positive cancers in clinical studies lack satisfactory results. It would be highly desirable to develop an effective therapy against MUC1-expressing cancers. In this study, we constructed a novel T cell-engaging bispecific antibody (BsAb) targeting MUC1 and CD3 with the Fab-ScFv-IgG format. A high quality of MUC1-CD3 BsAb can be acquired through a standard method. Our study suggested that this BsAb could specifically bind to MUC1- and CD3-positive cells and efficiently enhance T cell activation, cytokine release, and cytotoxicity. Furthermore, our study demonstrated that this BsAb could potently redirect T cells to eliminate MUC1-expressing tumor cells in vitro and significantly suppress MUC1-positive tumor growth in a xenograft mouse model. Thus, T cell-engaging MUC1/CD3 BsAb could be an effective therapeutic approach to combat MUC1-positive tumors and our MUC1/CD3 BsAb could be a promising candidate in clinical applications for the treatment of MUC1-positive cancer patients.

Therapeutic effect of a MUC1-specific monoclonal antibody-drug conjugates against pancreatic cancer model

BackgroundPancreatic cancer is one of the most aggressive malignancies without effective targeted therapies. MUC1 has emerged as a potential common target for cancer therapy because it is overexpressed in a variety of different cancers including the majority of pancreatic cancer. However, there are still no approved monoclonal antibody drugs targeting MUC1 have been reported. Recently, we generated a humanized MUC1 antibody (HzMUC1) specific to the interaction region between MUC1-N and MUC1-C. In this study, we generated the antibody drug conjugate (ADC) by conjugating HzMUC1 with monomethyl auristatin (MMAE), and examined the efficacy of HzMUC1-MMAE against the MUC1-positive pancreatic cancer in vitro and in vivo.MethodsWestern blot and immunoprecipitation were used to detect MUC1 in pancreatic cancer cells. MUC1 localization in pancreatic cancer cells was determined by confocal microscopy. HzMUC1 was conjugated with the monomethyl auristatin (MMAE), generating the HzMUC1-MMAE ADC. Colony formation assay and flow cytometry were used to assess the effects of the HzMUC1-MMAE cell viability, cell cycle progression and apoptosis. Capan-2 and CFPAC-1 xenograft model were used to test the efficacy of HzMUC1-MMAE against pancreatic cancer.ResultsHzMUC1 antibody binds to MUC1 on the cell surface of pancreatic cancer cells. HzMUC1-MMAE significantly inhibited cell growth by inducing G2/M cell cycle arrest and apoptosis in pancreatic cancer cells. Importantly, HzMUC1-MMAE significantly reduced the growth of pancreatic xenograft tumors by inhibiting cell proliferation and enhancing cell death.ConclusionOur results indicate that HzMUC1-ADC is a promising novel targeted therapy for pancreatic cancer. HzMUC1-ADC should also be an effective drug for the treatment of different MUC1-positive cancers.

The oncoprotein MUC1 facilitates breast cancer progression by promoting Pink1-dependent mitophagy via ATAD3A destabilization

Mitophagy is a vital process that controls mitochondria quality, dysregulation of which can promote cancer. Oncoprotein mucin 1 (MUC1) targets mitochondria to attenuate drug-induced apoptosis. However, little is known about whether and how MUC1 contributes to mitochondrial homeostasis in cancer cells. We identified a novel role of MUC1 in promoting mitophagy. Increased mitophagy is coupled with the translocation of MUC1 to mitochondria, where MUC1 interacts with and induces degradation of ATPase family AAA domain-containing 3A (ATAD3A), resulting in protection of PTEN-induced kinase 1 (Pink1) from ATAD3A-mediated cleavage. Interestingly, MUC1-induced mitophagy is associated with increased oncogenicity of cancer cells. Similarly, inhibition of mitophagy significantly suppresses MUC1-induced cancer cell activity in vitro and in vivo. Consistently, MUC1 and ATAD3A protein levels present an inverse relationship in tumor tissues of breast cancer patients. Our data validate that MUC1/ATAD3A/Pink1 axis-mediated mitophagy constitutes a novel mechanism for maintaining the malignancy of cancer cells, providing a novel therapeutic approach for MUC1-positive cancers.

DNA micelle-templated copper nanoclusters for fluorescent imaging of MUC1-positive cancer cells.

DNA micelles formed by hydrophobic, self-assembly of amphiphilic DNA monomers have enormous potential in biological imaging owing to its unique and programmable, three-dimensional nanostructure. Herein, we rationally design double-stranded DNA oligonucleotides with two cholesterols that can spontaneously form the lipid-mediated DNA micelles and generate the high fluorescence signal after the formation of DNA-templated copper nanoclusters (CuNCs). Furthermore, the DNA aptamer specific to MUC1 protein, aberrantly overexpressed on the surface of cancer cells, is attached to lipid-mediated DNA micelles to confer the selectivity towards the target cancer cells. With the well-defined DNA nanostructures, the cell membrane of MUC1-positive cancer cells are stained by CuNCs exhibiting an intense, red fluorescence signal, which are clearly distinguished from MUC1-negative cancer cells. This approach may not only expand the application scope of both DNA micells and CuNCs, especially in the area of cellular imaging, but also provides a basis for developing other types of DNA nanostructures to detect target biomarkers.

Self-Assembled DNA-Protein Hybrid Nanospheres: Biocompatible Nano-Drug-Carriers for Targeted Cancer Therapy.

We developed hybrid nanospheres comprised of two of the most important biomolecules in nature, DNA and proteins, which have excellent biocompatibility, high drug payload capacity, in vivo imaging ability, and in vitro/in vivo cancer targeting capability. The synthesis can be done in a facile one-pot assembly system that includes three steps: step-growth polymerization of two DNA oligomers, addition of streptavidin to assemble spherical hybrid nanostructures, and functionalization of hybrid nanospheres with biotinylated aptamers. To test the feasibility of cancer targeting and drug-loading capacity of the hybrid nanospheres, MUC1-specific aptamers (MA3) were conjugated to nanosphere surfaces (apt-nanospheres), and doxorubicin (Dox) was loaded into nanospheres by DNA intercalation. The successful construction of nanospheres and apt-nanospheres was confirmed by agarose gel electrophoresis and dynamic light scattering (DLS). Their uniform spherical morphology was confirmed by transmission electron microscopy (TEM). Fluorescence spectra of nanospheres demonstrated high Dox-loading capability and slow-release characteristics. In vitro MUC1-specific binding of the apt-nanospheres was confirmed by flow cytometry and confocal microscopy. Dox-loaded apt-nanospheres significantly increased cytotoxicity of the MUC1-positive cancer cells due to aptamer-mediated selective internalization, as shown via cell viability assays. Apt-nanospheres could also be imaged in vivo through the synthesis of hybrid nanospheres using fluorescent dye-conjugated DNA strands. Finally, in vivo specific targeting ability of apt-nanospheres was confirmed in a MUC1-positive 4T1 tumor-bearing mouse model, whereas apt-nanospheres did not cause any sign of systemic toxicity in normal mice. Taken together, our self-assembled DNA-streptavidin hybrid nanospheres show promise as a biocompatible cancer targeting material for contemporary nanomedical technology.

Aptamer-conjugated gold nanoparticles for targeted paclitaxel delivery and photothermal therapy in breast cancer

The development of novel therapeutic approaches with high efficiency and precision like photothermal therapy (PTT) is essential to combat breast cancer. The gold nanoparticle (AuNPs) has shown critical ability both in PTT and targeted delivery. Herein, we evolved targeted PTT in a multifunctional drug delivery platform. The AuNPs were modified by poly (ethylene glycol) (PEG) to improve their biocompatibility, and the mucin1 (MUC1) aptamer-modified PEG-AuNPs were successfully prepared. The Paclitaxel (PTX)–loaded PEG-AuNPs@antiMUC1 system displayed a dual NIR/pH-dependent sustained release. The synergistic effect of PTX/PEG-AuNPs@antiMUC1 was evaluated in this research. In vitro cell cytotoxicity experiments on MUC1-positive and MUC1-negative breast cancer cells showed the desired selectivity of the prepared system towards MUC1-positive cells. The capability of the PTX/PEG-AuNPs@antiMUC1 in combination with near-infrared (NIR) irradiation in ablation of MUC1-positive cancer cells with excellent cellular uptake was also witnessed. Furthermore, simultaneous utilization of PTT and targeted drug delivery indicated a synergistic effect that increased cell death versus seldom PTT or chemotherapy. The protein expression analysis confirmed the increased expression of the apoptotic Caspase3 and declined expression of the anti-apoptotic Bcl-xL in the presence of the prepared synergistic combinational system, which showed its high potentials in cancer therapy.

A novel humanized MUC1 antibody-drug conjugate for the treatment of trastuzumab-resistant breast cancer.

Mucin 1 (MUC1) has been regarded as an ideal target for cancer treatment, since it is overexpressed in a variety of different cancers including the majority of breast cancer. However, there are still no approved monoclonal antibody drugs targeting MUC1. In this study, we generated a humanized MUC1 (HzMUC1) antibody from our previously developed MUC1 mouse monoclonal antibody that only recognizes MUC1 on the surface of tumor cells. Furthermore, an antibody-drug conjugate (ADC) was generated by conjugating HzMUC1 with monomethyl auristatin (MMAE), and the efficacy of HzMUC1-MMAE on the MUC1-positive HER2+ breast cancer in vitro and in 'Xenograft' model was tested. Results from western blot analysis and immunoprecipitation revealed that the HzMUC1 antibody did not recognize cell-free MUC1-N in sera from breast cancer patients. Confocal microscopy analysis showed that HzMUC1 antibody bound to MUC1 on the surface of breast cancer cells. Results from mapping experiments suggested that HzMUC1 may recognize an epitope present in the interaction region between MUC1-N and MUC1-C. Results from colony formation assay and flow cytometry demonstrated that HzMUC1-MMAE significantly inhibited cell growth by inducing G2/M cell cycle arrest and apoptosis in trastuzumab-resistant HER2-positive breast cancer cells. Meanwhile, HzMUC1-MMAE significantly reduced the growth of HCC1954 xenograft tumors by inhibiting cell proliferation and enhancing cell death. In conclusion, our results indicate that HzMUC1-ADC is a novel therapeutic drug that can overcome trastuzumab resistance of breast cancer. HzMUC1-ADC should also be an effective therapeutic drug for the treatment of different MUC1-positive cancers in clinic.

Aptamer-guided DNA tetrahedrons as a photo-responsive drug delivery system for Mucin 1-expressing breast cancer cells

Photosensitizers are crucial for photodynamic therapy. However, conventional photosensitizers have poor selectivity, and their targeted delivery by nanocarriers has become a major research focus. The aim of this study was to construct a targeted delivery system for new photosensitizers using aptamer-guided DNA tetrahedra. Mucin 1 protein is overexpressed in some cancer cells. The sequence of a Mucin 1 aptamer (MUC1) was linked to a DNA tetrahedron to form MUC1 aptamer-modified tetrahedral nanostructures (MUC1-TDNs) for the selective targeting of MUC1-positive tumor cells. The photosensitizer, TMPyP4, was loaded into MUC1-TDNs owing to the high affinity of TMPyP4 for DNA; consequently, a targeted photosensitizer delivery system (MUC1-TDNs-TMPyP4, MTT) was obtained. This system allowed for the selective delivery of TMPyP4 to MUC1-positive cancer cells. Moreover, MTT promoted the production of reactive oxygen species as well as cytotoxicity in MUC1-positive cells, while less killing effect were observed in MUC1-negative cells. We designed a MUC1-targeted delivery system of photosensitizers based on DNA tetrahedron, thus providing a new approach for the targeted release of photosensitizers.

Targeted doxorubicin-loaded mesenchymal stem cells-derived exosomes as a versatile platform for fighting against colorectal cancer

Exosomes hold great potential for cancer treatment to deliver therapeutics due to its inherent low immunogenicity. Exosomes are biocompatible cell-exocytosed secreted vesicles by most cell types, which can be used to construct novel biomanufacturing platform for drug delivery and cancer therapy. In this study, we implemented nano-sized vesicles which were secreted by mesenchymal stem cell (MSC), to encapsulate doxorubicin (DOX) through electroporation method (DOX@exosome). DOX was loaded into exosomes, with an encapsulation efficiency of up to 35% and separated by ultracentrifugation.Subsequently, carboxylic acid-end MUC1 aptamer was used to covalently decorate the surface amine groups of the exosomes via amide bond formation to provide selective guided drug delivery (DOX@exosome-apt).The data showed that the DOX@exosome-apt provided highly efficient DOX transportation to MUC1-positive cancer cells in vitro as confirmed by MTT and flow cytometry experiments. Moreover, in vivo study on ectopic model of C26 (mouse colon adenocarcinoma) in BALB/c mice indicated that the single dose intravenous injection of DOX@exosome-apt significantly suppress tumor growth in comparison with free DOX. Ex vivo fluorescent imaging also verified the desirable biodistribution of DOX@exosome-apt by exhibiting higher tumor accumulation and faster liver clearance in comparison with DOX@exosome and free DOX. It could be concluded that MUC1 aptamer-decorated exosomes can be implemented therapeutically for the safe and versatile delivery of DOX to colon adenocarcinoma, thus offering valuable platform for clinical applications.

A VHH-Based Anti-MUC1 Chimeric Antigen Receptor for Specific Retargeting of Human Primary T Cells to MUC1-Positive Cancer Cells.

Objective Immunotherapy with redirected T cells that express a chimeric antigen receptor (CAR) is a promising prospect in cancer treatment. Most CARs use murine-derived single-chain variable fragments (scFvs) as an antigen targeting moiety, which may lead to host immunogenic responses and engineered T cell disappearance. It seems that development of less immunogenic CARs, such as CARs composed of the camelid variable domain of heavy chain antibodies (VHHs) may likely overcome this obstacle. Here, we improved the expression of the VHH-based anti-MUC1 CAR gene construct using a third generation lentiviral vector in primary human T cells and assessed its effect on antigen specific targeting, activation and cytotoxicity of redirected human T cells. Materials and Methods In this experimental study, we established a second generation novel CAR (VHH-based anti- MUC1 CAR) that contained a camelid-derived anti-MUC1 VHH followed by an IgG3 hinge, a CD28 transmembrane domain and signalling endodomains of CD28 and CD3+. Next, we constructed lentiviral vectors that contained this CAR gene construct using an optimized transiently virus production method and transduced it into human T cells. Cell surface expression of CAR, cytokine secretion and cytotoxic activity were assessed in the transduced CD3+T cells. Results The transduced T cells had high levels of surface expression of CAR. T cells that expressed anti-MUC1 CAR showed significantly increased secretion of Th1 cytokines, including IL-2, TNF alpha and IFN-γ, as well as cytotoxic activity upon recognition of MUC1 on tumour cells after co-incubation with T47D or MCF-7 (MUC1-positive) compared with A431 (MUC1-negative) or untransduced T cells. ConclusionOur results suggested that, given the unique properties of VHHs to prevent immunogenic responses and tonic signalling, our novel VHH-based anti-MUC1 CAR might be effective for clinical purposes in cancer immunotherapy.

MUC1 induces acquired chemoresistance by upregulating ABCB1 in EGFR-dependent manner

Chemoresistance contributes to cancer relapse and increased mortality in a variety of cancer types, raising a pressing need to better understand the underlying mechanism. MUC1 is abnormally overexpressed in numerous carcinomas and associated with poor prognosis. However, the functional significance of MUC1 in chemoresistance has not been fully elucidated. Here, we showed that MUC1 expression was considerably induced in cells that had acquired chemoresistance at both transcriptional and post-translational levels. Using gain- and loss-of function approaches, we demonstrated a critical role of MUC1 in induction of drug resistance. Through stimulation of EGFR activation and nuclear translocation, MUC1 increased the expression of ATP-binding cassette transporter B1 (ABCB1). Remarkably, targeted suppression of EGFR or ABCB1 by both shRNAs and inhibitors effectively reversed chemoresistance. Moreover, co-administration of the inhibitors of MUC1–EGFR–ABCB1 with paclitaxel significantly blocked not only tumor growth but also relapse in xenograft mouse model. Our data collectively support a model in which MUC1 induces acquired chemotherapy resistance by upregulating ABCB1 in an EGFR-dependent manner, providing a novel molecular basis of using the EGFR inhibitor in MUC1-positive cancers to prevent chemotherapy resistance.

Aptamer-guided DNA tetrahedron as a novel targeted drug delivery system for MUC1-expressing breast cancer cells in vitro.

Mucin 1 (MUC1) is an important molecular target for cancer treatment because it is overexpressed in most adenocarcinomas. In this study, a new MUC1-targeted drug delivery system was assembled using an aptamer (Apt) that could recognize MUC1 and a DNA tetrahedron (Td) that could carry doxorubicin (Dox) within its DNA structure. The complex thus formed (Apt-Td) had an average size of 12.38 nm and was negatively charged. Similar to the MUC1 aptamer, the Apt-Td could preferentially bind with MUC1-positive MCF-7 breast cancer cells. A drug loading experiment revealed that each Apt-Td complex could carry approximately 25 Dox molecules. Moreover, Apt-Td selectively delivered Dox into the MUC1-positive breast cancer cells but reduced Dox uptake by the MUC1-negative control cells. Dox-loaded Apt-Td also induced a significantly higher cytotoxicity to the MUC1-positive cancer cells versus the MUC1-negative control cells in vitro (p<0.01). These results suggest that Apt-Td may potentially serve as a drug carrier in the targeted treatment of MUC1-expressing breast cancers.

Enhancement of Thermal Damage to Adenocarcinoma Cells by Iron Nanoparticles Modified with MUC1 Aptamer.

Hyperthermia cancer treatment is an adjunctive therapy that aims at killing the tumor cells with excessive heat that is usually generated by metal contrasts exposed to alternating magnetic field. The efficacy of hyperthermia is often limited by the heat damage to normal tissue due to indiscriminate distribution of the metal contrasts within the body. Tumor-targeting metal contrasts may reduce the toxicity of hyperthermia and improve the efficacy of thermotherapy against cancer. MUC1 is a glycoprotein over expressed in most adenocarcinomas, and represents an attractive therapeutic target. In this study, a MUC1 aptamer is conjugated with iron nanoparticles to construct adenocarcinoma-targeting metal contrasts. DNA hybridization studies confirmed that the aptamers were conjugated to the iron nanoparticles. Importantly, more aptamer-modified nanoparticles attached to the MUC1-positive cancer cells compared with the unmodified nanoparticles. Moreover, aptamer-modified nanoparticles significantly enhanced the targeted hyperthermia damage to MUC1-positive cancer cells in vitro (p < 0.05). The results suggest that MUC1 aptamer-modified metal particles may have potential in development of targeted hyperthermia therapy against adenocarcinomas.

A Novel Approach of Targeted Immunotherapy against Adenocarcinoma Cells with Nanoparticles Modified by CD16 and MUC1 Aptamers

Mucin 1 (MUC1) is a potentially important target of cancer therapy, being a glycoprotein that is overexpressed on cell surface of many types of adenocarcinomas, including breast, ovarian, colon, lung, and prostatic cancers. Several MUC1‐targeted drug delivery systems have been developed and reported, but mobilizing natural killer cells (NK) to fight against MUC1‐positive tumor has not been attempted. In this study, we introduced a novel amphipathic nanoparticle (NP) for enhancing the NK cytotoxicity to MUC1‐positive cancer cells. The amphipathic NP had CD16 and MUC1 aptamers on its surface and was designed to bind with both the CD16‐positive NK cells and the MUC1‐positive tumor cells and pull the two types of cells close to each other. The fabricated amphipathic NP had an average size of 574 nm. The aptamers’ conjugation with the NP was confirmed by DNA hybridization experiments. Dark‐field microscopy revealed that the amphipathic NP could recruit more NK cells to the vicinity of MUC1‐positive cancer cells. Additionally, the amphipathic NP significantly enhanced the NK cytotoxicity to MUC1‐positive cancer cells (p &lt; 0.01), but not that to the MUC1‐negative control cells. The results suggest that NK cells may potentially be mobilized to selectively fight against MUC1‐positive cancer cells.

A randomized, double-blind, placebo-controlled, multicenter, multinational, phase II trial immunotherapy with L-BLP25 (tecemotide) in patients with colorectal carcinoma following R0/R1 hepatic metastasectomy.

TPS3124^ Background: 15-20% of all patients (pts) diagnosed with colorectal cancer (crc) develop metastases (mets) surgical resection remains the only potentially curative treatment available. Current 5-year survival rate following R0 resection of liver mets lies between 28-39%, recurrence occurs in up to 70% of pts. To date, adjuvant chemotherapy has not significantly improved clinical outcomes. The primary objective of the ongoing LICC trial (L-BLP25 In Colorectal Cancer) is to determine whether L-BLP25, an active MUC1-specific cancer immunotherapy, extends recurrence-free survival (RFS) time over placebo in crc pts following R0/R1 resection of liver mets known to highly express MUC1 glycoprotein. Phase III data from L-BLP25 in NSCLC will be reported at this meeting. Methods: This is a multinational, phase II, multicenter, randomized, double-blind, placebo-controlled trial with a sample size of 159 pts from 20 centers in 3 countries. Pts must have stage IV cr adenocarcinoma limited to liver mets. Following curative-intent complete resection of the primary tumor and of all synchronous/metachronous mets, eligible pts are randomized 2:1 to receive either L-BLP25 or placebo. L-BLP25 arm receives a single dose of 300 mg/m2 cyclophosphamide (CPA) 3 d before 1st L-BLP25 dose, then primary treatment with sc L-BLP25 930 μg weekly for 8 weeks, followed by sc L-BLP25 930 μg maintenance doses at 6-week (year 1 and 2) and 12-week (year 3) intervals until recurrence. Control arm: CPA is replaced by saline solution and L-BLP25 by placebo. Primary endpoint (PE) is RFS time. Secondary endpoints: Overall survival (OS), safety, tolerance, RFS/OS in MUC-1 positive cancers. Exploratory immune response analyses are planned. Study start was in Q3 2011. 19 centers were initialized and 36 patients recruited, no SUSARs occurred. Study recruitment will end Q3 2013: follow-up until Q3 2017. PE assessment is in Q3 2016. Interim analyses are not planned.No major practical issues were identified during setup and early conduct of the study. Clinical trial information: 2011-000218-20.

A randomized, double-blind, placebo-controlled, multicenter, multinational, phase II trial of L-BLP25 in patients with colorectal carcinoma following R0/R1 hepatic metastasectomy.

TPS3641^ Background: Approximately 15-20% of patients diagnosed with colorectal cancer (crc) develop metastatic disease. Surgical resection remains the only potentially curative treatment. 5-year survival following R0-resection of liver metastases lies ~28 -39%. Recurrence occurs in ~70% of pts. Adjuvant chemotherapy has not significantly improved clinical outcomes. The primary objective of the LICC trial (L-BLP25 in Colorectal Cancer) is to analyze whether L-BLP25, an active cancer immunotherapy, extends recurrence-free survival (RFS) time over placebo in colorectal cancer pts following R0/R1 resection of hepatic metastases. L-BLP25 targets MUC1 glycoprotein, which is highly expressed in hepatic metastases from crc. In a phase IIB trial, L-BLP25 showed acceptable tolerability and a trend toward longer survival in pts with stage IIIB NSCLC. Methods: This is a multinational, phase II, multicenter, randomized, double-blind, placebo-controlled trial with a sample size of 159 pts from 20 centers in 3 countries. Pts must have stage IV cr adenocarcinoma limited to liver metastases. Following complete resection of the primary tumor and all syn-/metachronous metastases, eligible pts are randomized 2:1 to receive either L-BLP25 or placebo. Those allocated to L-BLP25 receive a single dose of 300 mg/m2 cyclophosphamide (CP) 3 days before first L-BLP25 dose, then primary treatment with sc L-BLP25 930 μg once weekly for 8 weeks, followed by maintenance doses at 6-week (years 1 and 2) and 12-week (year 3) intervals until recurrence. In the control arm, CP is replaced by saline solution and L-BLP25 by placebo. Primary endpoint: RFS time. Secondary endpoints: OS time, safety status, tolerability, RFS/OS in MUC-1 positive cancers. Exploratory immune response analyses are planned. First recruitment was of Q3 2011. To date, 8 of 20 centers are initiated and 4 pts recruited. Completion of recruitment is scheduled for Q3 2013. Primary endpoint will be assessed in Q3 2016: Follow-up will end Q3 2017. No interim analysis is planned. Design and implementation of this vaccination study in colorectal cancer is feasible. No major issues identified during setup of the study.

LICC: L-BLP25 in patients with colorectal carcinoma after curative resection of hepatic metastases--a randomized, placebo-controlled, multicenter, multinational, double-blinded phase II trial

Background15-20% of all patients initially diagnosed with colorectal cancer develop metastatic disease and surgical resection remains the only potentially curative treatment available. Current 5-year survival following R0-resection of liver metastases is 28-39%, but recurrence eventually occurs in up to 70%. To date, adjuvant chemotherapy has not improved clinical outcomes significantly. The primary objective of the ongoing LICC trial (L-BLP25 In Colorectal Cancer) is to determine whether L-BLP25, an active cancer immunotherapy, extends recurrence-free survival (RFS) time over placebo in colorectal cancer patients following R0/R1 resection of hepatic metastases. L-BLP25 targets MUC1 glycoprotein, which is highly expressed in hepatic metastases from colorectal cancer. In a phase IIB trial, L-BLP25 has shown acceptable tolerability and a trend towards longer survival in patients with stage IIIB locoregional NSCLC.Methods/DesignThis is a multinational, phase II, multicenter, randomized, double-blind, placebo-controlled trial with a sample size of 159 patients from 20 centers in 3 countries. Patients with stage IV colorectal adenocarcinoma limited to liver metastases are included. Following curative-intent complete resection of the primary tumor and of all synchronous/metachronous metastases, eligible patients are randomized 2:1 to receive either L-BLP25 or placebo. Those allocated to L-BLP25 receive a single dose of 300 mg/m2 cyclophosphamide (CP) 3 days before first L-BLP25 dose, then primary treatment with s.c. L-BLP25 930 μg once weekly for 8 weeks, followed by s.c. L-BLP25 930 μg maintenance doses at 6-week (years 1&2) and 12-week (year 3) intervals unless recurrence occurs. In the control arm, CP is replaced by saline solution and L-BLP25 by placebo. Primary endpoint is the comparison of recurrence-free survival (RFS) time between groups. Secondary endpoints are overall survival (OS) time, safety, tolerability, RFS/OS in MUC-1 positive cancers. Exploratory immune response analyses are planned. The primary endpoint will be assessed in Q3 2016. Follow-up will end Q3 2017. Interim analyses are not planned.DiscussionThe design and implementation of such a vaccination study in colorectal cancer is feasible. The study will provide recurrence-free and overall survival rates of groups in an unbiased fashion.Trial RegistrationEudraCT Number 2011-000218-20

Autoantibodies against the signal peptide domain of MUC1 in patients with multiple myeloma: Implications for disease diagnosis and prognosis

Naturally generated autoantibodies to tumor-associated antigens such as MUC1 can assist in cancer diagnosis and prognosis. While previous studies have concentrated on the tandem repeat array domain of MUC1, here we focused on MUC1's signal peptide domain. We used ELISA assays with MUC1-specific epitopes and antibodies to quantify soluble MUC1 antigen and anti-MUC1 autoantibodies against the tandem repeat array and signal peptide domains in 15 naïve donors and 27 multiple myeloma cancer patients. We showed a significant increase in up to 24-fold (P<0.004) only in the levels of anti-MUC1 signal peptide autoantibodies in the sera of multiple myeloma patients vs. naïve donors. This increase stemmed chiefly from the preferred immunogenicity of the signal peptide. Moreover, a significant positive correlation (R(2)=0.5361, P<0.048, Pearson correlation) was shown between the levels of soluble MUC1 and anti-MUC1 signal peptide autoantibodies in multiple myeloma patients with progressive disease while under therapy. This is an initial report on the existence of autoantibodies to a signal peptide domain in general and to the MUC1 signal peptide domain in particular in cancer patients. The autoantibodies had MUC1 rather than signal peptide specificity. The specific nature of the antigen leading to generation of these autoantibodies is still unclear because it is unlikely that the target antigen is a major histo-compatibility complex-peptide complex and we could not trace soluble MUC1 signal peptide fragments in naïve donors and multiple myeloma patients. Further validation of these findings may improve diagnostic and prognostic capabilities for MUC1-positive multiple myeloma patients and potentially, patients with other MUC1-positive cancers, as well.

LICC: L-BLP25 in patients with colorectal carcinoma after curative resection of hepatic metastases—A randomized, double-blind, placebo-controlled, multicenter, multinational, phase II trial.

TPS166 Background: Distant metastases limited to the liver occur in 15-20% of all patients initially diagnosed with colorectal cancer. Complete surgical resection represents the only curative option. The 5-year survival after R0-resection of liver metastases ranges between 28 and 39%. Unfortunately, recurrence rates peak up to 70% in long-term follow-up. Adjuvant chemotherapeutic protocols did not reveal significant improvement of the situation. The primary objective of the LICC trial is to determine whether the therapeutic cancer vaccine L-BLP25 extends recurrence-free survival (RFS) time over placebo in colorectal cancer patients after resection of hepatic metastases. L-BLP25 targets the MUC1 glycoprotein, which is highly expressed in hepatic metastases of colorectal cancer. In a phase IIB trial, L-BLP25 showed acceptable tolerability and a trend toward longer survival in patients (pts) with stage IIIB locoregional NSCLC. Methods: This is a planned multinational, phase II, multicenter, randomized, double-blind trial. Planned sample size is 159 pts from 20 centers in 3 countries; accrual is planned to start in Q3 2011. Pts with colorectal adenocarcinoma after complete resection of the primary tumor and having experienced a curative-intent resection of all hepatic metastases (R0/R1, metachronous/synchronous, <6 weeks) are eligible. Pts will be randomized 2:1 to receive either L-BLP25 or placebo. Those in the L-BLP25 arm receive a single dose of cyclophosphamide (CP) (300 mg/m2) 3 days before first L-BLP25 dose, then primary treatment with sc L-BLP25 930 μg once weekly for 8 weeks, followed by sc L-BLP25 930 μg maintenance doses at 6-week (years 1&2) and 12-week (year 3) intervals until recurrence. In the control arm, CP is replaced by NaCl solution and L-BLP25 by placebo. Stratified: R0 vs. R1. Primary endpoint: RFS time between treatment groups. Secondary endpoints: overall survival (OS) time, safety, tolerability, RFS/OS in MUC-1 positive cancers. Exploratory immune response analyses are planned. Evaluation of primary endpoint is planned for Q3 2016.