Engineering CD3/CD137 Dual Specificity into a DLL3-Targeted T-Cell Engager Enhances T-Cell Infiltration and Efficacy against Small-Cell Lung Cancer

Small-cell lung cancer (SCLC) is an aggressive cancer for which immune checkpoint inhibitors (ICI) have had only limited success. Bispecific T-cell engagers are promising therapeutic alternatives for ICI-resistant tumors, but not all patients with SCLC are responsive. Herein, to integrate CD137 costimulatory function into a T-cell engager format and thereby augment therapeutic efficacy, we generated a CD3/CD137 dual-specific Fab and engineered a DLL3-targeted trispecific antibody (DLL3 trispecific). The CD3/CD137 dual-specific Fab was generated to competitively bind to CD3 and CD137 to prevent DLL3-independent cross-linking of CD3 and CD137, which could lead to systemic T-cell activation. We demonstrated that DLL3 trispecific induced better tumor growth control and a marked increase in the number of intratumoral T cells compared with a conventional DLL3-targeted bispecific T-cell engager. These findings suggest that DLL3 trispecific can exert potent efficacy by inducing concurrent CD137 costimulation and provide a promising therapeutic option for SCLC.

A bispecific antibody NXT007 exerts a hemostatic activity in hemophilia A monkeys enough to keep a nonhemophilic state

BACKGROUND

Emicizumab, a factor (F) VIIIa-function mimetic bispecific antibody (BsAb) to FIXa and FX, has become an indispensable treatment option for people with hemophilia A (PwHA). However, a small proportion of PwHA still experience bleeds even under emicizumab prophylaxis, as observed in the long-term outcomes of clinical studies. A more potent BsAb may be desirable for such patients.

OBJECTIVES

To identify a potent BsAb to FIXa and FX, NXT007, surpassing emicizumab by in vitro and in vivo evaluation.

METHODS

New pairs of light chains for emicizumab's heavy chains were screened from phage libraries, and subsequent antibody optimization was performed. For in vitro evaluation, thrombin generation assays were performed with hemophilia A plasma. In vivo hemostatic activity was evaluated in a nonhuman primate model of acquired hemophilia A.

RESULTS

NXT007 exhibited an in vitro thrombin generation activity comparable to the international standard activity of FVIII (100 IU/dL), much higher than emicizumab, when triggered by tissue factor. NXT007 also demonstrated a potent in vivo hemostatic activity at approximately 30-fold lower plasma concentrations than emicizumab's historical data. In terms of dose shift between NXT007 and emicizumab, the in vitro and in vivo results were concordant. Regarding pharmacokinetics, NXT007 showed lower in vivo clearance than those shown by typical monoclonal antibodies, suggesting that the Fc engineering to enhance FcRn binding worked well.

CONCLUSION

NXT007, a potent BsAb, was successfully created. Nonclinical results suggest that NXT007 would have a potential to keep a nonhemophilic range of coagulation potential in PwHA or to realize more convenient dosing regimens than emicizumab.

Abstract 1872: A DLL3/CD3/CD137 trispecific T cell engager shows potent antitumor activity in small cell lung cancer models

Background: Despite the approval of immune checkpoint inhibitors (ICIs), prognosis of small cell lung cancer (SCLC) remains poor. DLL3 is upregulated in SCLC whereas expression in normal tissues is minimal, representing the favorable profile as a therapeutic target. T cell engager (TCE) is a potent immunotherapy that redirects T cells to tumors expressing a specific antigen. Unlike ICIs, TCEs do not require the recognition of tumor antigens by T cells and thus could be an alternative approach to target tumors where the benefit of ICIs is limited such as SCLC. CD137 (4-1BB) is a costimulatory molecule that promotes T cell activation, proliferation, and survival. Since CD137 agonists synergize with CD3-mediated T cell activation, inducing concurrent CD137 costimulation is a promising strategy to unleash the potential of TCEs. We therefore developed a DLL3/CD3/CD137 trispecific T cell engager composed of two CD3/CD137 dual specific Fabs and one extra DLL3 Fab (DLL3 trispecific, RG6524).

Results: We initially investigated the CD3 and CD137 signal transduction in Jurkat cells harboring NFAT or NF-κB reporter cocultured with DLL3 positive cells. DLL3 trispecific showed dose-dependent increase in NFAT and NF-κB activity, indicating that target engagement successfully activated CD3 and CD137 signaling. In the in vitro assay using human PBMC, DLL3 trispecific induced cytotoxicity against SCLC cell lines with EC50s in the two-digit pM range.

In vivo efficacy was evaluated in SCLC xenograft models established by engrafting SCLC cell lines into immune humanized NOG mice. DLL3 trispecific showed greater tumor growth inhibition compared to a traditional bispecific T cell engager. Furthermore, flow cytometry-based immunophenotyping revealed that DLL3 trispecific increased T cell number in tumors and improved IFN-γ production from CD8 T cells. We also explored the combination with platinum-based drugs, which are widely used for SCLC, and showed that DLL3 trispecific enhanced the efficacy of platinum-based drugs. These data demonstrated that DLL3 trispecific has the potent in vivo efficacy and the potential for clinical use.

We next evaluated whether cytokine release syndrome (CRS) mitigating approaches affect antitumor efficacy. Although prophylactic use of a steroid significantly reduced cytokine production, tumor growth inhibition by DLL3 trispecific remained unchanged. Likewise, tocilizumab treatment did not reduce the efficacy, suggesting that CRS mitigation did not abrogate the therapeutic benefit.

We finally assessed the tolerability in non-human primates. DLL3 trispecific did not reach the maximum tolerated dose and was well tolerated up to 16 mg/kg Q2D, the highest dose tested.

Conclusion: Our data showed that DLL3 trispecific has potent activity and is well suited for clinical application in SCLC. These findings provide a rationale for the clinical testing of DLL3 trispecific.

Citation Format: Hirofumi Mikami, Shu Feng, Sotaro Naoi, Yumiko Azuma, Yoko Kayukawa, Toshiaki Tsunenari, Kentaro Asanuma, Ryutaro Iwabuchi, Hiroaki Nagano, Junko Shinozuka, Masaki Yamazaki, Haruka Kuroi, Siok Wan Gan, Priyanka Chichili, Shun Shimizu, Yutaka Matsuda, Shinya Ishii, Shogo Kamikawaji, Yasuko Kinoshita, Yuichiro Shimizu, Akihisa Sakamoto, Masaru Muraoka, Noriyuki Takahashi, Tatsuya Kawa, Hirotake Shiraiwa, Kenji Kashima, Futa Mimoto, Mika Kamata-Sakurai, Takehisa Kitazawa, Tomoyuki Igawa. A DLL3/CD3/CD137 trispecific T cell engager shows potent antitumor activity in small cell lung cancer models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1872.

Efficient production of bispecific antibody by FAST-IgTM and its application to NXT007 for the treatment of hemophilia A

Efficient production of bispecific antibodies (BsAbs) in single mammalian cells is essential for basic research and industrial manufacturing. However, preventing unwanted pairing of heavy chains (HCs) and light chains (LCs) is a challenging task. To address this, we created an engineering technology for preferential cognate HC/LC and HC/HC paring called FAST-Ig (Four-chain Assembly by electrostatic Steering Technology - Immunoglobulin), and applied it to NXT007, a BsAb for the treatment of hemophilia A. We introduced charged amino-acid substitutions at the HC/LC interface to facilitate the proper assembly for manufacturing a standard IgG-type BsAb. We generated CH1/CL interface-engineered antibody variants that achieved > 95% correct HC/LC pairing efficiency with favorable pharmacological properties and developability. Among these, we selected a design (C3) that allowed us to separate the mis-paired species with an unintended pharmacological profile using ion-exchange chromatography. Crystal structure analysis demonstrated that the C3 design did not affect the overall structure of both Fabs. To determine the final design for HCs-heterodimerization, we compared the stability of charge-based and knobs into hole-based Fc formats in acidic conditions and selected the more stable charge-based format. FAST-Ig was also applicable to stable CHO cell lines for industrial production and demonstrated robust chain pairing with different subclasses of parent BsAbs. Thus, it can be applied to a wide variety of BsAbs both preclinically and clinically.

Monte Carlo Thompson sampling-guided design for antibody engineering

Antibodies are one of the predominant treatment modalities for various diseases. To improve the characteristics of a lead antibody, such as antigen-binding affinity and stability, we conducted comprehensive substitutions and exhaustively explored their sequence space. However, it is practically unfeasible to evaluate all possible combinations of mutations owing to combinatorial explosion when multiple amino acid residues are incorporated. It was recently reported that a machine-learning guided protein engineering approach such as Thompson sampling (TS) has been used to efficiently explore sequence space in the framework of Bayesian optimization. For TS, over-exploration occurs when the initial data are biasedly distributed in the vicinity of the lead antibody. We handle a large-scale virtual library that includes numerous mutations. When the number of experiments is limited, this over-exploration causes a serious issue. Thus, we conducted Monte Carlo Thompson sampling (MTS) to balance the exploration-exploitation trade-off by defining the posterior distribution via the Monte Carlo method and compared its performance with TS in antibody engineering. Our results demonstrated that MTS largely outperforms TS in discovering desirable candidates at an earlier round when over-exploration occurs on TS. Thus, the MTS method is a powerful technique for efficiently discovering antibodies with desired characteristics when the number of rounds is limited.

In vitro toxicological support to establish specification limit for anti-CD3 monospecific impurity in a bispecific T cell engager drug, ERY974

An emerging structure for anti-tumor antibody drugs utilizes a bispecific antibody (BiAb) that recognizes a tumor surface antigen and CD3 on T cells. An impurity that commonly contaminates these BiAb products is an anti-CD3 monoclonal antibody (mAb). The most plausible cause of toxic activity by an anti-CD3 mAb is the induction of cytokines via T cell activation. In this in vitro study, we compared cytokine induction and T cell activation after treatment with an anti-glypican-3/CD3 BiAb (ERY974), anti-CD3 mAb impurity (aCD3), or ERY974 spiked with 5% aCD3. We found that contamination with up to 5% aCD3 did not affect cytokine release by ERY974. Cytokine levels induced by ERY974 in the presence of target cells were significantly higher than those induced by aCD3, but were very similar to those by the spiked treatment. The results supported the specification of a 5% limit for aCD3. OKT-3 had much higher activity to induce cytokines from peripheral blood mononuclear cells in an in vitro assay than aCD3. This suggests that specification limit should be decided for each type of anti-CD3 impurity that affects T cell-activating BiAb drug products. In vitro cytokine assays can provide useful information for determining these specification limits.

Engineering a bispecific antibody with a common light chain: Identification and optimization of an anti-CD3 epsilon and anti-GPC3 bispecific antibody, ERY974

The antibody drug market is rapidly expanding, and various antibody engineering technologies are being developed to create antibodies that can provide better benefit to patients. Although bispecific antibody drugs have been researched for more than 30 years, currently only a limited number of bispecific antibodies have achieved regulatory approval. Of the few successful examples of industrially manufacturing a bispecific antibody, the "common light chain format" is an elegant technology that simplifies the purification of a whole IgG-type bispecific antibody. Using this IgG format, the bispecific function can be introduced while maintaining the natural molecular shape of the antibody. In this article, we will first introduce the outline, prospects, and limitations of the common light chain format. Then, we will describe the identification and optimization process for ERY974, an anti-glypican-3 × anti-CD3ε T cell-redirecting bispecific antibody with a common light chain. This format includes one of Chugai's proprietary technologies, termed ART-Ig technology, which consists of a method to identify a common light chain, isoelectric point (pI) engineering to purify the desired bispecific IgG antibody from byproducts, and Fc heterodimerization by an electrostatic steering effect. Furthermore, we describe some tips for de-risking the antibody when engineering a T cell redirecting antibody.

An anti–glypican 3/CD3 bispecific T cell–redirecting antibody for treatment of solid tumors

Cancer care is being revolutionized by immunotherapies such as immune checkpoint inhibitors, engineered T cell transfer, and cell vaccines. The bispecific T cell–redirecting antibody (TRAB) is one such promising immunotherapy, which can redirect T cells to tumor cells by engaging CD3 on a T cell and an antigen on a tumor cell. Because T cells can be redirected to tumor cells regardless of the specificity of T cell receptors, TRAB is considered efficacious for less immunogenic tumors lacking enough neoantigens. Its clinical efficacy has been exemplified by blinatumomab, a bispecific T cell engager targeting CD19 and CD3, which has shown marked clinical responses against hematological malignancies. However, the success of TRAB in solid tumors has been hampered by the lack of a target molecule with sufficient tumor selectivity to avoid “on-target off-tumor” toxicity. Glypican 3 (GPC3) is a highly tumor-specific antigen that is expressed during fetal development but is strictly suppressed in normal adult tissues. We developed ERY974, a whole humanized immunoglobulin G–structured TRAB harboring a common light chain, which bispecifically binds to GPC3 and CD3. Using a mouse model with reconstituted human immune cells, we revealed that ERY974 is highly effective in killing various types of tumors that have GPC3 expression comparable to that in clinical tumors. ERY974 also induced a robust antitumor efficacy even against tumors with nonimmunogenic features, which are difficult to treat by inhibiting immune checkpoints such as PD-1 (programmed cell death protein–1) and CTLA-4 (cytotoxic T lymphocyte–associated protein–4). Immune monitoring revealed that ERY974 converted the poorly inflamed tumor microenvironment to a highly inflamed microenvironment. Toxicology studies in cynomolgus monkeys showed transient cytokine elevation, but this was manageable and reversible. No organ toxicity was evident. These data provide a rationale for clinical testing of ERY974 for the treatment of patients with GPC3-positive solid tumors.

Abstract 1482: Anti-GPC3 TRAB, a first-in-class T cell-redirecting bispecific antibody targeting glypican-3 with potent in vitro and in vivo antitumor efficacy against solid tumors

We present efficacy data for the T cell-redirecting antibody (TRAB) with highly potent anti-tumor efficacy. Anti-Glypican-3 (GPC3) TRAB is a humanized IgG4 bispecific antibody that simultaneously binds to GPC3 on the cancer cell surface and to CD3 on the T cell surface. Anti-GPC3 TRAB utilizes T cells as effectors to induce strong TRAB dependent cellular cytotoxicity (TDCC) in the presence of GPC3-expressing cells. Treatment with anti-GPC3 TRAB first activates T cells by increasing the expression of CD25 and CD69 and also upregulating cytokines IL-2, IL-4, IL-6, IL 10, IFNγ, and TNF, and then it enhances the proliferation of T cells. Anti-GPC3 TRAB showed antitumor activity against xenograft tumors derived from various cancer types — MKN-74 (human gastric adenocarcinoma), PC-10 (human lung squamous cell carcinoma), TOV-21G (human ovarian clear cell carcinoma), and KYSE70 (human esophageal squamous cell carcinoma) — in a NOD-SCID mouse model injected with human T cells. Although recent immunotherapy, as represented by immune check point inhibitors PD-1, PD-L1, and CTLA-4 antibodies, showed promising efficacy in human, not every patient can benefit from this immunotherapy, because the significant efficacy shown in patients by a blockade of immune checkpoints is closely related to the tumor microenvironment. The immune check point inhibitors show high efficacy against inflamed tumors, because these have been sufficiently infiltrated by cytotoxic T cells that recognize cancer-specific antigens. However, they do not have efficacy against non inflamed tumors. In an immunocompetent mouse model using human CD3 transgenic mice, neither the inhibitors that block immune checkpoints (such as PD-1, PD-L1 and CTLA-4) nor a conventional ADCC antibody recognizing GPC3 could show significant efficacy against a poorly immunogenic LLC1/hGPC3 tumor. However, anti-GPC3 TRAB showed efficacy against this poorly immunogenic tumor by utilizing any kind of T cell as effectors irrespective of TCR specificity, including not only CD8-positive but also CD4-positive T cells.

The studies we present show that anti-GPC3 TRAB is a promising drug with high efficacy utilizing all kinds of T cells as effectors. The compound is expected to have efficacy even in patients with poorly immunogenic tumors, in which an immune checkpoint blockade fails to show efficacy.

Citation Format: Yasuko Kinoshita, Takahiro Ishiguro, Yuji Sano, Yumiko Azuma, Toshiaki Tsunenari, Natsuki Ono, Yoko Kayukawa, Otoya Ueda, Naoko A. Wada, Hiroshi Hino, Koichi Jishage, Hirotake Shiraiwa, Mika Kamata-Sakurai, Junichi Nezu, Mika Endo. Anti-GPC3 TRAB, a first-in-class T cell-redirecting bispecific antibody targeting glypican-3 with potent in vitro and in vivo antitumor efficacy against solid tumors. [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 1482.

A defucosylated anti-CD317 antibody exhibited enhanced antibody-dependent cellular cytotoxicity against primary myeloma cells in the presence of effectors from patients

The humanized monoclonal antibody (mAb) against CD317 antigen (anti-HM1.24 antibody; AHM), which is highly expressed on multiple myeloma (MM), induces antibody-dependent cellular cytotoxicity (ADCC). However, the antitumor activity of AHM in the clinical setting has not been clearly demonstrated. In this study, we produced defucosylated AHM and evaluated its potency for clinical application by performing autologous ADCC assays against primary MM cells from patients. Defucosylated AHM that was produced in rat myeloma YB2/0 cells expressing a low level of fucosyltransferase (FUT8) showed significant ADCC activity against three out of six primary MM cells in the presence of autologous PBMC, whereas conventional AHM did not. The results indicate that the potency of AHM to induce ADCC against primary MM cells was insufficient, but was significantly augmented by defucosylation. To generate more homogenous defucosylated monoclonal antibodies (mAb) for fermentation, we disrupted the GFT gene that encodes a GDP-fucose transporter in a CHO/DXB11 cell line by sequential homologous recombination. Analysis of the N-linked oligosaccharide in the defucosylated AHM produced by the established GFT(-/-)CHO cell line showed that a majority (93.4%) of the oligosaccharide was fucose free. The GFT(-/-) cells stably produced defucosylated mAb over passages. These results demonstrate that GTF(-/-)CHO-produced defucosylated AHM (GFTKO-AHM) will be a promising new therapeutic antibody against MM in the clinical setting.

Detection of Grb-2-related Adaptor Protein Gene (GRAP) and Peptide Molecule in Salivary Glands of MRL/lpr Mice and Patients with Sjögren's Syndrome

The pathogenesis of Sjögren's syndrome (SS) is poorly understood. In this study we used an in-house mouse spleen cDNA microarray to analyse genes in spleens from MRL/lpr (an SS mouse model) mice. We have previously demonstrated that GRAP genes were up-regulated in salivary glands of the same mice. The microarray analysis showed that seven out of 2304 genes were highly expressed in spleens from the MRL/ lpr mice, one of which was the GRAP gene. In other words, the GRAP gene is highly expressed in the salivary glands and spleen of MRL/lpr mice. We also carried out immunohistochemical studies. Mouse and human Grb-2-related adaptor protein ( GRAP) antigens were expressed on ductal cells and infiltrating lymphocytes in salivary glands of MRL /lpr mice and SS patients, but only weakly in controls (MRL/+ mice and individuals with salivary cysts). These results suggest that the GRAP gene might have a role in the pathogenesis of SS.

A New Tactile Skin Sensor for Measuring Skin Hardness in Patients with Systemic Sclerosis and Autoimmune Raynaud's Phenomenon

We used a new tactile sensor to measure the elastic properties of skin in patients with systemic sclerosis or Raynaud's phenomenon. The sensor consists of a piezoelectric vibrator with vibration pickup to measure frequency changes when the sensor is placed on the skin. The mean frequency change at the skin surface of the proximal third phalanx in patients with systemic sclerosis was significantly lower than in age- and sex-matched controls. The results in systemic sclerosis patients were statistically correlated to the Modified Rodnan Skin Thickness Score. This technique was also used to measure the therapeutic efficacy of salpogrelate, a new specific serotonin receptor antagonist. A greater mean frequency change was seen after treatment. We conclude that this new tactile sensor is useful for quantitatively measuring skin sclerosis and may help determine the efficacy of therapeutic treatments.

Increased soluble CD4 molecules and the role of soluble CD4 production in patients with rheumatoid arthritis

We investigated the concentration of soluble CD4 molecules (sCD4) in serum, and the mechanism of sCD4 production from T lymphocytes, in patients with rheumatoid arthritis (RA). The concentration of sCD4 molecules was determined using a solid-phase enzyme-linked immunosorbent assay method. Using reverse transcription polymerase chain reaction (RT-PCR) techniques, we studied the presence of alternatively spliced mRNA encoding the transmembrane site of CD4, and the mRNA encoding a conservative region of the CD4 binding site of the human immunodeficiency virus (HIV), in the serum of RA patients. Levels of sCD4 found in RA patients were higher than in normal controls (199 U/ml compared with 8.4 U/ml, respectively), and correlated with additional medical parameters. The results of RT-PCR suggested that the higher sCD4 levels may be due to shedding from the cell membrane after protease digestion, not to alternative splicing or a reaction to viral binding to sCD4.

[Urinary tumor marker for urothelial cancer]

The urinary tumor markers BTA, BFP and NMP22 used for urothelial cancer in Japan are reviewed briefly. We also evaluate and compare the sensitivity and specificity of BTA, BFP and NMP22 with urine cytology in detecting bladder cancer in 24 of our patients. The results showed that the sensitivity with urine cytology, BTA, BFP and NMP22 was 37, 54, 66 and 62% respectively. The specificity of BTA, BFP and NMP22 with urine cytology was 100, 65, 60 and 70% respectively. The sensitivity with BTA, BFP and NMP22 for urothelial cancer was higher than that with urine cytology. However, all except for urine cytology showed high false positive rates (83-90%) for urinary tract infection. These markers may thus complement urine cytology, which has a low sensitivity for urothelial cancer. Quite possibly they could act as low-cost and useful tumor markers, which could in turn reduce the number of invasive cystoscopic examinations. However, considering their high false positive rates for benign disease such as urinary tract infection, we must acknowledge that an ideal urothelial tumor marker, which is simple, non-invasive, inexpensive and accurate with high sensitivity and specificity has yet to be developed.

The role of osteopontin in the development of granulomatous lesions in lung

Osteopontin (OPN) has been shown to be expressed by cells in granulomas of various origins, but whether it plays a functional role in granuloma formation is not known. Here we used a cardiomyopathic hamster (TO2) model, to test the hypothesis that OPN contributes functionally to granuloma development. We immunized cardiomyopathic and normal hamsters by subcutaneous injection of bovine serum albumin in complete Freund's adjuvant, and assessed various tissues for both OPN RNA expression and granuloma formation. Cardiomyopathic hamsters expressed OPN, and formed granulomatous lesions, in heart tissue in both immunized and untreated animals. In addition, immunization induced expression of OPN in lung and lymph nodes of cardiomyopathic (but not normal) hamsters, and also induced granuloma formation in these organs. To test whether OPN expression could play a functional role in inducing granulomas, we produced an adenoviral vector containing the murine OPN gene, and introduced this vector intratracheally into the lungs of normal hamsters. The OPN-containing vector, but not the control vector, induced pulmonary granuloma formation. These studies provided direct in vivo evidence that OPN can contribute functionally to the formation of granulomatous lesions, and suggest that OPN expression may be a common factor involved in formation of granulomas of various origin.

[A case of primary aldosteronism presenting hypokalemic myopathy induced by benidipine hydrochloride; a dihydropyridine calcium channel blocker]

We report a 46-year-old man with primary aldosteronism presenting hypokalemia, periodic paralysis and hypokalemic myopathy whose clinical course paralleled with the dosage of benidipine hydrochloride, a dihydropyridine calcium channel blocker (DHP-CCB), administered for the treatment of hypertension. To see relations between DHP-CCB and episodes of motor weakness in patients with primary aldosteronism, we surveyed retrospectively the history of motor weakness and anti-hypertensive drugs in 14 consecutive cases with primary aldosteronism in our institute. Five patients out of 11 cases (45.5%) who had received DHP-CCB experienced muscle weakness, however, the rest of three patients receiving other anti-hypertensive drug had not experienced weakness. Though, less attention has been paid as thiazide diuretics, it is reported that DHP-CCB also induces hypokalemia through several mechanisms. However, the occurrence of motor weakness by DHP-CCB is very rare. Our results show that primary aldosteronism should be taken into account when we encounter patients manifesting episodic motor weakness by the use of DHP-CCB.

High rate of induction of human autologous cytotoxic T lymphocytes against renal carcinoma cells cultured with an interleukin cocktail

A high rate of induction (9 of 10 cases) of human autologous cytotoxic T lymphocytes (CTL) was achieved in vitro from peripheral blood mononuclear cells of renal carcinoma patients by applying an interleukin (IL)-cocktail consisting of IL-1, -2, -4, and -6. The CTL specifically lysed their own target carcinoma cells within 24 h but did not kill neighboring autologous normal kidney cells or allogeneic renal cancer cell lines. In the case of TUHR4TKB, for which autologous CTL were not induced, no expression of MHC class-I molecules was observed on the surface of these carcinoma cells, although they were sensitive to autologous natural killer cells. The results imply that adoptive immunotherapy for metastasized renal carcinoma will be feasible with autologous CTL in combination with natural killer cells.

Change in heart rate variability preceding ST elevation in a patient with vasospastic angina pectoris

A case of vasospastic angina (VSA) in a 62-year-old man with frequent ST elevation throughout the day was reported. His coronary angiogram showed that intracoronary methylergometrine had induced total occlusion due to a vasospasm. Analysis by Holter monitoring suggested that the autonomic nervous system would contribute differently to the initiation of the coronary spasm depending on whether the VSA attacks occurred during the daytime or at night. During the nighttime, the high-frequency power (HF: 0.15-0.4 Hz) decreased during the 2 min before ST elevation, and the heart rate increased immediately before ST elevation. The low-frequency power (LF: 0.04-0.15 Hz) and the ratio of LF to HF (LF/HF) did not significantly change before ST elevation. In contrast, each of the heart rate variability components and the heart rate did not significantly change before ST elevation during the daytime. Thus, the pathophysiology of VSA during the daytime and nighttime seems to be different in its relation to autonomic tone. During the nighttime, vagal withdrawal may be a component of the mechanisms leading to VSA, while during the daytime, a change in autonomic tone may not play a major role in this case.

Silent cerebral infarction associated with coronary artery disease

To investigate the relationship of coronary artery disease and silent cerebral infarction, 50 patients who underwent coronary arteriography and cranial magnetic resonance imaging were studied. The patients were divided into three groups. The incidence of silent cerebral infarction (chiefly lacunar infarction) was significantly higher in patients with old myocardial infarction and in those with angina pectoris than in the control group (80, 78 and 29%, respectively, p < 0.05). Silent cerebral infarction is considered to be a risk factor for symptomatic cerebrovascular disease, so more attention should be focussed on the prevention of stroke in patients with coronary artery disease.

[Retroperitoneal liposarcoma with intrarenal metastases which was difficult to distinguish from angiomyolipoma. A case report]

A 40-year-old man was admitted to our hospital with a fat-density extrarenal tumor and intrarenal nodules which were detected by ultrasonography (US) and CT scan obtained the general health check. After his admission, US, CT, MRI and angiography were performed. As the final diagnostic procedure, we performed a US-guided percutaneous needle biopsy of the extrarenal tumor, because this tumor was difficult to distinguish from liposarcoma and angiomyolipoma (AML). The pathological study revealed a well-differentiated liposarcoma, and the extrarenal tumor and the left kidney were removed en bloc. Pathologically, the tumor not only invaded into the renal parenchyma directly but also have metastasized independently to the intrarenal region. Postoperatively, he received a tumor dose of irradiation of 50 Gy. Liposarcoma arising in the perirenal space should be considered in the differential diagnosis of exophytic AML. If radiological studies can not confirm the appropriate diagnosis, we consider that biopsy of the tumor should be selected as an alternative diagnostic approach. And, we think that this is the first case report dealing with intrarenal metastases of liposarcoma.

[A case report of an ectopic ureter in a patient treated for chronic prostatitis]

A male aged 20 had been treated for anal and lower abdominal pain after ejaculation for about 2 years under the diagnosis of chronic prostatis. Because of worsening of the pain, he was admitted to our hospital in September 24, 1991. On the rectal examination, a cystic tumor was palbable on the left side of the prostate. The left kidney was not detected by IVP and ultrasonography. CT revealed two retrovesical cystic lesions in the left side. Cystourethroscopy showed an absence of ureteral orifice and ureteral ridge on the left side. Left uretero-seminal vesiculectomy was performed on October 3rd, under the diagnosis of an ectopic ureter entering into the seminal vesicle or ejaculatory duct. Histopathologically, the left ectopic ureter entering into the lower portion of the seminal vesicle or ejaculatory duct and the left renal agenesis were diagnosed. It was remarkable that ureteral epithelium was not transitional but columnar epithelium.

[Phenotypic difference of lymphocytes circulating in tumorous renal artery and renal vein in patients with renal cell carcinoma]

Phenotypic difference of lymphocytes circulating in tumorous renal artery and renal vein in patients with renal cell carcinoma was studied. Fifteen patients with no prior treatment were studied, from whom blood samples were taken at the time of radical nephrectomy. Mononuclear cells separated from tumorous renal arterial and venous blood were analyzed for cell surface markers. CD3, CD4, CD8, CD11b, CD16, CD25, CD57, Leu8 HLA-DR were compared. CD25 positive cells were significantly increased in venous blood than in arterial blood in the kidneys with tumor. No significant difference was found regarding the other surface markers.

A feasible method for expansion of peripheral blood lymphocytes by culture with immobilized anti-CD3 monoclonal antibody and interleukin-2 for use in adoptive immunotherapy of cancer patients

Cultivation of T lymphocytes with immobilized anti-CD3 monoclonal antibody and human recombinant interleukin-2 induced a rapid proliferative response. This procedure was applied to expansion culture of peripheral blood lymphocytes obtained from cancer patients for use in adoptive immunotherapy. Peripheral blood mononuclear cells were separated from 20 ml of blood and cultured in anti-CD3 coated flasks with rIL-2 for 6 days, then transferred to a gas-permeable culture bag and culture continued for an additional 8 days with an increasing volume of medium. Cell numbers increased about 2000-fold during this 2-week culture. The final population contained about 30% CD4+ and 60% CD8+ cells, and all were CD3+ & HLA-DR+. NK cells comprised less than 5%. In clinical trials involving 12 cases receiving 35 infusions, the mean number of harvested T cells after 14 days culture was 3.5 x 10(10) (R = 1.6-6.8 x 10(10)), and the mean expansion index was 1560-fold (R = 409-4091). This method could be of benefit not only in immunotherapy but also for obtaining somatic cells from a small volume of blood for use in molecular or genetic analysis instead of having to perform EB virus transformation of B cells.

Distribution and therapeutic effect of intraarterially transferred tumor-infiltrating lymphocytes in hepatic malignancies. A preliminary report

Indium-111-labeled tumor-infiltrating lymphocytes (111In-TIL) were transferred as an intrahepatic arterial bolus to determine their in vivo distribution in patients with hepatic malignancies. In the in vitro culture system, TIL were expanded upon simultaneous stimulation by recombinant interleukin-2 (rIL-2) and immobilized anti-CD3 monoclonal antibody. This double activation led not only to a larger cell yield, but also to a significantly more dominant subpopulation with CD4+ phenotype than occurred with activation by rIL-2 alone. Accumulations of 111In-TIL in the liver were identified by scintigraphy in all of three patients, corresponding to the tumor localization by computed tomography. Such accumulation had persisted for at least 48 hours after infusion. After intraarterial chemoimmunotherapy that included TIL, two of three patients achieved a partial therapeutic response. The authors conclude that their method of culture and transfer can facilitate the accumulation of TIL at tumor sites, which may augment the antitumor effects of adoptive immunotherapy.

A new form of specific targeting cancer immunotherapy using anti-tumor monoclonal antibody-conjugated lymphokine-activated killer cells

Cross-linking of effector T cells to target cancer cells augments their tumor lytic activities. Here we describe a new method of conjugating lymphokine-activated killer (LAK) cells with cancer-specific monoclonal antibody. The LAK cells were biotinylated, treated with avidin, and conjugated with biotinylated monoclonal antibody. These monoclonal antibody-conjugated LAK cells showed specifically enhanced killing activities against anti-tumor antibody-reactive cancer cells, and cold target cells specifically inhibited their activities.

Evaluation of the invasive potential of superficial bladder cancer by adenosine triphosphate measurement

In order to predict the malignant potential of superficial bladder cancer, in 121 patients with this malignancy adenine nucleotide levels (adenosine triphosphate, adenosine diphosphate, and adenosine monophosphate) and energy charge in bladder cancer cells were determined. The nucleotides were analyzed according to the method of Bücher, and the energy charge was calculated by applying the formula of Atkinson. It was clearly pointed out that superficial bladder tumors, which became invasive and/or metastatic, had higher levels of adenylate compounds than those which became not. Our results show that a high correlation exists between adenine nucleotide content and tumor progression.

[Diagnosis of pheochromocytoma by 131I-MIBG scintigraphy]

Between February, 1984, and June, 1988, 131I-metaiodobenzylguanidine (131I-MIBG) scintigraphy was performed on 48 patients with suspected pheochromocytoma at our hospital. Whole body image and/or spot images were obtained 24, 48 and 72 hours after injection of 0.5 mCi of 131I-MIBG. In 10 of 12 patients with surgically proven pheochromocytoma, 131I-MIBG was accumulated in the primary and metastatic tumor. 131I-MIBG scintigraphy was negative in 2 patients. One case of renal cyst had the accumulation of 131I-MIBG but the disease could be confirmed. By 131I-MIBG scintigraphy sensitivity was 83% (10/12), and specificity was 97% (35/36). Heart intensity was much higher in patients with nonpheochromocytoma than those with pheochromocytoma. Thus 131I-MIBG scintigraphy proved to be safe, non-invasive and specific in the diagnosis of pheochromocytoma.

[A recurrent gastric carcinoma found by metastasis to the scrotum]

Reported is a case of 67-year-old man with a recurrent gastric carcinoma that was associated with a possible lymphatic metastasis to the scrotum. Seven years earlier (October, 1980), since an adenocarcinoma of the stomach was present, a subtotal gastrectomy was performed. At that time, a IIc-like advanced tumor with a ul-III, measuring 32 x 28 mm in size, was noted on the anterior wall of the corpus near the greater curvature of the stomach, on macroscopical examination of the resected specimen. Microscopic findings showed a poorly differentiated adenocarcinoma with an involvement of the serosa but without a lymph node metastasis (H0, P0, n0, se, stage III). In July 1987, a tumor in the right scrotum was found and the patient underwent surgery. The resected specimen revealed a histologically cancerous involvement of the testis, the epididymis, the tunica vaginalis testis, and the spermatic cord. The cancerous cells showed the same poorly differentiated adenocarcinoma which had been observed in the primary locus of the stomach. Judging from these findings, this case was diagnosed as a recurrent gastric carcinoma with a lymphatic metastasis to the scrotum.