Pilot study of HER2 targeted 64 Cu-DOTA-tagged PET imaging in gastric cancer patients

OBJECTIVE

Human epidermal growth factor receptor 2 (HER2) is an important biomarker for targeted gastric cancer (GC) immunotherapy. However, heterogeneous HER2 overexpression in GC, loss of HER2 expression during therapy, and inability to non-invasively identify HER2 overexpressing tumors impede effective targeting therapies. Improved HER2-specific functional imaging can address these challenges. Trastuzumab is a HER2-directed mAb to treat HER2 overexpressing cancers. The 64 Cu-DOTA-trastuzumab radiotracer is used to detect HER2+ metastatic breast cancer. We aimed to develop 64 Cu-DOTA-trastuzumab PET-CT to detect and characterize tumor uptake in HER2+ or - GC patients.

METHODS

We conducted a single-arm phase II pilot study exploring the feasibility of 64 Cu-DOTA-trastuzumab for PET imaging of HER2 overexpressing GC compared to HER2 non-expressing tumors. Eight patients with biopsy-confirmed gastric adenocarcinoma were included. Immunohistochemistry was used to evaluate primary tumor biopsies for HER2 overexpression. Patients were injected with 45 mg of cold trastuzumab followed by 5 mg of 64 Cu-DOTA-trastuzumab. PET-CT scans were performed 24-48 h post radiotracer injection and compared to standard staging CT scans.

RESULTS

We observed limited toxicity following 64 Cu-DOTA-trastuzumab injections. While there was uptake of the radiotracer in portions of HER2+ lesions, there was no statistically significant distinction between tumor and background by standardized uptake value analysis.

CONCLUSION

Despite the potential of 64 Cu-DOTA-trastuzumab PET imaging of HER2+ metastatic breast cancer, a 5 mg dose of this radiotracer injected 24-48 h before imaging was insufficient to identify HER2+ GC. These results inform future GC imaging studies to optimize biomarker-targeted therapies based on dosage and timing for more clinically relevant imaging.

Phase I study of intratumoral administration of CF33-HNIS-antiPDL1 in patients with metastatic triple negative breast cancer

e13070

Background: Despite recent FDA approval of immune checkpoint inhibitor pembrolizumab and drug-antibody conjugate in the treatment of metastatic triple negative breast cancer (mTNBC), the overall survival benefit of these therapies remains modest. Oncolytic virotherapy (OV) utilizes genetically modified viruses to infect and kill cancer cells while sparing healthy cells. CF33-hNIS-anti-PD-L1 (CHECKvacc) is a novel chimeric orthopoxvirus with robust anti-cancer activity in TNBC xenografts. Cells infected with CHECKvacc were shown to express functional human sodium-iodide symporter (hNIS) and anti-PD-L1 proteins. hNIS gene transfer allows tracking of virus by 99mTc single-photon emission computed tomography (SPECT). Our preliminary animal studies demonstrated that tumor cells infected with CHECKvacc successfully secrete functional hNIS and anti-PD-L1. CHECKvacc is safe and well-tolerated, and detects and effectively kills TNBC at doses several magnitudes lower than other OVs in xenograft models. Methods: This study is a first-in-human (FIH) phase I, single center, single arm clinical trial evaluating the safety and tolerability of CHECKvacc intratumoral injection in patients with mTNBC. Key eligibility criteria include patients with unresectable or metastatic TNBC; progressed on at least 2 prior chemotherapies including immune checkpoint inhibitor-containing regimen; ECOG 0-1; RECIST 1.1 measurable disease; and at least one tumor amenable to repeated intratumoral injections. Eligible patients receive CHECKvacc intratumorally at one of 8 assigned dose levels (1 × 105 PFU, 3 × 105 PFU, 1 × 106 PFU, 3× 106 PFU, 1 × 107 PFU, 3 × 107 PFU, 1 × 108 PFU, 3 x 108 PFU) on Days 1 and 15 of each 28-day cycle for a total of 3 cycles of treatment. Primary objectives are to evaluate the safety and tolerability of CHECKvacc (DLTs and other toxicities by CTCAE v5.0). Secondary objectives are to determine optimal biological dose (OBD), recommended phase II dose (RP2D), and response rate by RECIST1.1. Results: The first 3 subjects of dose level 1 will be enrolled sequentially for safety monitoring. Once the initial 3 subjects are treated sequentially, the study will follow the Phase I Queue 3+3 (IQ 3+3) design which expands a dose level up to 8 subjects after a single DLT has been observed. Enrollment to the final RP2D may be expanded to include up to 12 patients for efficacy assessment. The estimated targeted accrual is 33 patients (minimum) to 78 patients (maximum). Correlative aims include assessing viral kinetics, viral plaque assay, 99mTc SPECT imaging for virus tracking, peripheral blood and tumor tissue for antiviral immune activation, and tumor microenvironment changes in association with response to therapy. Conclusions: This FIH trial of CF33-hNIS-antiPD-L1 intratumoral injection in patients with mTNBC is currently underway. Clinical trial information: NCT05081492.

Anti-CD25 radioimmunotherapy with BEAM autologous hematopoietic cell transplantation conditioning in Hodgkin lymphoma

High-risk relapsed or refractory (R/R) classical Hodgkin lymphoma (HL) is associated with poor outcomes after conventional salvage therapy and autologous hematopoietic cell transplantation (AHCT). Post-AHCT consolidation with brentuximab vedotin (BV) improves progression-free survival (PFS), but with increasing use of BV early in the treatment course, the utility of consolidation is unclear. CD25 is often expressed on Reed-Sternberg cells and in the tumor microenvironment in HL, and we hypothesized that the addition of 90Y-antiCD25 (aTac) to carmustine, etoposide, cytarabine, melphalan (BEAM) AHCT would be safe and result in a transplantation platform that is agnostic to prior HL-directed therapy. Twenty-five patients with high-risk R/R HL were enrolled in this phase 1 dose-escalation trial of aTac-BEAM. Following an imaging dose of 111In-antiCD25, 2 patients had altered biodistribution, and a third developed an unrelated catheter-associated bacteremia; therefore, 22 patients ultimately received therapeutic 90Y-aTac-BEAM AHCT. No dose-limiting toxicities were observed, and 0.6 mCi/kg was deemed the recommended phase 2 dose, the dose at which the heart wall would not receive >2500 cGy. Toxicities and time to engraftment were similar to those observed with standard AHCT, though 95% of patients developed stomatitis (all grade 1-2 per Bearman toxicity scale). Seven relapses (32%) were observed, most commonly in patients with ≥3 risk factors. The estimated 5-year PFS and overall survival probabilities among 22 evaluable patients were 68% and 95%, respectively, and non-relapse mortality was 0%. aTac-BEAM AHCT was tolerable in patients with high-risk R/R HL, and we are further evaluating the efficacy of this approach in a phase 2 trial. This trial was registered at www.clinicaltrials.gov as #NCT01476839.

Phase I Study of Yttrium-90 Radiolabeled M5A Anti-Carcinoembryonic Antigen Humanized Antibody in Patients with Advanced Carcinoembryonic Antigen Producing Malignancies

Background: M5A is a humanized monoclonal antibody (mAb) directed against carcinoembryonic antigen (CEA) The purpose of this first in human phase I dose-escalation trial was to characterize the toxicities and determine the maximum tolerated dose (MTD) of yttrium-90 (90Y)-DOTA-M5A as a single agent and in combination with gemcitabine (gem). Methods: Patients with advanced metastatic CEA-producing malignancies who had progressed on standard therapies were first administered indium-111 (111In)-DOTA-M5A. If tumor targeting was observed, the patient then received the therapy dose of 90Y-DOTA-M5A. Serial scans, blood sampling, and 24 h urine collections were then performed to estimate radiation doses to organs and total body. Assays for human antihuman antibody (HAHA) responses were performed out to 6 months. Results: Of the 18 patients who received 111In-DOTA-M5A, 16 received 90Y-DOTA-M5A therapy; 1 patient at 14 mCi/m2 with gem (150 mg/m2 days 1and 3), 3 patients at 12 mCi/m2 with gem, 6 patients at 12 mCi/m2 without gem, and 6 at 10 mCi/m2 without gem. Prolonged cytopenias resulted in discontinuation of dose escalation with gemcitabine. A single agent MTD of 10 mCi/m2 was established based on dose-limiting hematopoietic toxicities. HAHA immune response was identified in 2 of 16 patients (12.5%). Stable disease at 3 months was seen in 10 patients and 2 patients demonstrated an 88% and 64% decrease in CEA back to normal levels. In 2 patients 111In-DOTA-M5A imaging revealed previously unknown brain metastases. Conclusion: This study demonstrates the potential utility of the 90Y-DOTA-M5A anti-CEA mAb as a therapeutic antibody. There is decreased immunogenicity compared with murine and chimeric mAbs, allowing for the potential of multiple administrations. Combined modality therapy approaches incorporating this agent should continue to be evaluated.

Phase II Study of Yttrium-90 Ibritumomab Tiuxetan Plus High-Dose BCNU, Etoposide, Cytarabine, and Melphalan for Non-Hodgkin Lymphoma: The Role of Histology

Standard-dose 90yttrium-ibritumomab tiuxetan (.4 mci/kg) together with high-dose BEAM (BCNU, etoposide, cytarabine, and melphalan) (Z-BEAM) has been shown to be a well-tolerated autologous hematopoietic stem cell transplantation preparative regimen for non-Hodgkin lymphoma. We report the outcomes of a single-center, single-arm phase II trial of Z-BEAM conditioning in high-risk CD20+ non-Hodgkin lymphoma histologic strata: diffuse large B cell (DLBCL), mantle cell, follicular, and transformed. Robust overall survival and notably low nonrelapse mortality rates (.9% at day +100 for the entire cohort), with few short- and long-term toxicities, confirm the safety and tolerability of the regimen. In addition, despite a high proportion of induction failure patients (46%), the promising response and progression-free survival (PFS) rates seen in DLBCL (3-year PFS: 71%; 95% confidence interval, 55 to 82%), support the premise that the Z-BEAM regimen is particularly effective in this histologic subtype. The role of Z-BEAM in other strata is less clear in the context of the emergence of novel agents.

SU-E-T-261: Determination of Initial Exposure Rates and Clearance Constants in a Sequence of 165 Consecutive Thyroid Cancer Patients Undergoing NaI-131 Therapy

PURPOSE

Following surgery, papillary and follicular thyroid cancers are usually treated with oral administration of NaI-131. In order to estimate subsequent staff, family, and public exposures, it is important to measure both exposure rates as well as the time of clearance of residual activity from these individuals. There is the additional possibility that patient whole-body absorbed dose estimates may be made using the data.

METHODS

During the historical interval 2006 - 2010, a total of 165 consecutive thyroid cancer patients were assayed at the time of activity administration and over the following several days. Using a calibrated radiation detector, exposure rates at one meter from the navel were measured between 2 and 5 times before release. By using these measurements and assuming a single-exponential clearance, we were able to evaluate initial exposure rates as well as the biological rate constant [k(biol)] for clearance of I-131 from the body.

RESULTS

Regression analyses were used to fit the initial exposure [X(0)] results as a function of administered activity. By least-squares, the slope was determined to be 0.15 mR/h/mCi over a clinically determined activity range of 25 to 250 mCi. At a given activity, there was wide variation of X(0) due to individual factors such as amount of residual thyroid mass and body habitus. For example, at 150 mCi, X(0) varied from 15 to 35 mR/h at one meter with the average being 25 mR/h. For the 165 patients, the mean biological clearance constant was 0.049/h.

CONCLUSION

Average initial exposure rates at one meter from 165 NaI-131 patients have been determined. The biological clearance was seen to be much more rapid than the physical decay constant for I-131 (0.0036/h). At a given activity level, variation of exposure rates was approximately +/- 40% over the corresponding patient population.

A pretherapy biodistribution and dosimetry study of indium-111-radiolabeled trastuzumab in patients with human epidermal growth factor receptor 2-overexpressing breast cancer

PURPOSE

The purposes of this study were to evaluate the organ biodistribution, pharmacokinetics, immunogenicity, and tumor uptake of (111)Indium ((111)In)-MxDTPA-trastuzumab in patients with human epidermal growth factor receptor 2 (HER2)-overexpressing breast cancers and to determine whether (90)Y-MxDTPA-trastuzumab should be evaluated in subsequent clinical therapy trials.

EXPERIMENTAL DESIGN

Patients with HER2-overexpressing breast cancers who were to undergo planned trastuzumab therapy first received unlabeled trastuzumab (4-8 mg/kg IV), followed 4 hours later by 5 mCi (111)In-MxDTPA-trastuzumab (10 mg antibody). Serial blood samples, 24-hour urine collections, and nuclear scans were performed at defined time points for 7 days.

RESULTS

Eight (8) patients received (111)In-MxDTPA-trastuzumab, which was well tolerated with no adverse side-effects. Three (3) of 7 patients with known lesions demonstrated positive imaging on nuclear scans. No antiantibody responses were observed for 2 months postinfusion. Organ doses (cGy/mCi) assuming radiolabeling with (90)Y were 19.9 for heart wall, 17.6 for liver, 4.6 for red marrow, and 2.8 for the whole body. Tumor doses ranged from 24 to 172 cGy/mCi.

CONCLUSIONS

In summary, results from this study indicate that (90)Y-MxDTPA-trastuzumab is an appropriate agent to evaluate in therapy trials. No evidence of an immune response to (111)In-MxDTPA-trastuzumab was detected, predicting for the ability to administer multiple cycles. With the exception of cardiac uptake, pharmacokinetics and organ biodistribution were comparable to other (90)Y-labeled monoclonal antibodies previously evaluated in the clinic. Cardiac uptake was comparable to hepatic uptake and therefore predicted to not be prohibitively high as to result in dose-limiting cardiotoxicity.

Phase II trial of a transplantation regimen of yttrium-90 ibritumomab tiuxetan and high-dose chemotherapy in patients with non-Hodgkin's lymphoma

PURPOSE

This phase II trial evaluated the safety and efficacy of combining yttrium-90 (90Y) ibritumomab tiuxetan with high-dose carmustine, cytarabine, etoposide, and melphalan (BEAM) and autologous stem-cell transplantation in patients with non-Hodgkin's lymphoma who were considered ineligible for total-body irradiation because of older age or prior radiotherapy.

PATIENTS AND METHODS

Between May 2002 and January 2006, 14 days before autologous stem-cell transplantation, 41 patients with non-Hodgkin's lymphoma received standard-dose 90Y ibritumomab tiuxetan (14.8 MBq/kg [0.4 mCi/kg]) followed by high-dose BEAM.

RESULTS

The median age was 60 years (range, 19 to 78 years), and the median number of previous therapies was two (range, one to six). Disease histologies were diffuse large B-cell (n = 20), mantle cell (n = 13), follicular (n = 4), and transformed lymphoma (n = 4). With a median follow-up of 18.4 months (range, 5.5 to 53.3 months) the estimated 2-year overall and progression-free survival were 88.9% (95% CI, 75.3% to 95.2%) and 69.8% (95% CI, 56.4% to 79.7%). The median time to WBC engraftment was 11 days (range, 9 to 26 days) and time to platelet engraftment was 12 days (range, 3 to 107 days). Adverse events were similar to those seen historically with high-dose BEAM alone, and included grade 3 or 4 pulmonary toxicity in 10 patients.

CONCLUSION

Adding 90Y ibritumomab tiuxetan to high-dose BEAM with autologous stem-cell transplantation is feasible and has a toxicity and tolerability profile similar to that observed with BEAM alone. Rates of progression-free survival seen in these patients are promising and warrant additional study.

A phase 1/2 trial of high-dose yttrium-90-ibritumomab tiuxetan in combination with high-dose etoposide and cyclophosphamide followed by autologous stem cell transplantation in patients with poor-risk or relapsed non-Hodgkin lymphoma

We conducted a phase 1/2 trial of high-dose 90Y-ibritumomab tiuxetan in combination with high-dose etoposide (VP-16) 40 to 60 mg/kg (day -4) and cyclophosphamide 100 mg/kg (day -2) followed by autologous stem cell transplantation (ASCT) in 31 patients with CD20+ non-Hodgkin lymphoma (NHL). Patients underwent dosimetry (day -21) with 5 mCi (185 MBq) 111In-ibritumomab tiuxetan following 250 mg/m2 rituximab, followed a week later by 90Y-ibritumomab tiuxetan to deliver a target dose of 1000 cGy to highest normal organ. Bone marrow biopsy was done on day -7 to estimate radiation dose and stem cells were reinfused when the radiation dose was estimated to be less than 5 cGy. The median 90Y-ibritumomab tiuxetan dose was 71.6 mCi (2649.2 MBq; range, 36.6-105 mCi; range, 1354.2-3885 MBq). Histology included follicular lymphoma (n = 12), diffuse large B-cell (n = 14), and mantle cell (n = 5). The median number of prior chemo-therapy treatments was 2. The treatment was well tolerated. The median times to reach an absolute neutrophil count greater than 500/microL and platelet count more than 20,000/microL were 10 days and 12 days, respectively. There were 2 deaths and 5 relapses. At a median follow-up of 22 months, the 2-year estimated overall survival and relapse-free survival rates are 92% and 78%, respectively. We conclude that high-dose 90Y-ibritumomab tiuxetan can be combined safely with high-dose etoposide and cyclophosphamide without an increase in transplant-related toxicity or delayed engraftment.

Three-dimensional culture of newborn rat utricle using an extracellular matrix promotes formation of a cyst

The vestibule is the end organ devoted to sensing of head movements in space. To function properly, its mechano-receptors require the presence of a unique apical extracellular medium, the endolymph. Numerous studies have elucidated the mechanisms involved in the production and homeostasis of this unique medium and the responses of sensory cells to stimulation. However, anatomical constraints have prevented direct and simultaneous studies of their relationships. The aim of this study was the development of an in vitro model that would allow concomitant investigations on maturation and physiological properties of both the hair cells and their endolymphatic compartment. A three-dimensional (3D) culture of newborn rat utricles using an extracellular matrix sustaining 3D cellular growth was developed during 3, 6, or 10 days in vitro (DIV). Using morphological and electrophysiological techniques, we describe the de novo formation of a cyst. It was composed of the sensory epithelium and non-sensory cells-canalar, dark and intermediate cells-that polarized so that their apical surface faced its lumen. During the time of culture, the utricular potential (UP) was steady (-1.1+/-5.0 mV) in oxygenated condition, while in anoxia, the UP significantly decreased to -8.4+/-1.0 mV at 8 DIV. Over the same period, the K+ concentration in the cyst increased up to 86.1+/-33.9 mM (versus 5.6+/-1.5 mM in the bath). These observations indicated that the mechanisms generating the UP and the K-secretory activity were functional at this stage. Concomitantly, the hair cells acquired mature and functional properties: the type 1 and type 2 phenotypes, a mean resting membrane potential of -68.1+/-4.6 mV and typical electrophysiological responses. This preparation provides a powerful means to simultaneous access the hair cells and their endolymphatic compartment, with the possibility to use multi-technical approaches to investigate their interdependent relationships.

Hyaluronic acid prevents peripheral nerve adhesion

The purpose of this study was to clarify the effectiveness of hyaluronic acid (HA) in the prevention of scar formation after neurolysis using a rabbit model. In the first stage, the left sciatic nerve was exposed and elevated along a 3 cm section. Then, the surface of the neural bed was coagulated using a bipolar coagulator. Finally, the sciatic nerve was replaced and fixed to the neural bed with 8/0 nylon sutures, and the wound was closed. In the second stage, the adherent sciatic nerve was re-exposed after 6 weeks. In the neurolysis group, a simple neurolysis was performed. In the HA group, the neurolysis was performed in a surgical field coated with HA from the beginning to the end of the operation. In the steroid group, methyl prednisolone acetate was infiltrated at the end of the neurolysis. In the third stage, electrophysiological, histological and biomechanical measurements were taken 6 weeks after the second stage. While there was no significant difference between the HA and the steroid groups, the electrophysiological functions of the HA and steroid groups were significantly better than that of the neurolysis group. Histology showed that the formation of intraneural and extraneural scar tissue was lowest in the HA group, followed by the steroid and neurolysis groups. The tensile strength required to strip the sciatic nerve from the neural bed of the HA group was significantly less than that of the neurolysis group. However, there was no significant difference between the steroid and neurolysis groups. In conclusion, HA effectively reduced scar formation after neurolysis.

A TGACGT motif in the 5'-upstream region of alpha-amylase gene from Vigna mungo is a cis-element for expression in cotyledons of germinated seeds

Alpha-amylase is expressed at high levels in cotyledons of germinated seeds of Vigna mungo. The mRNA for alpha-amylase appeared in cotyledons of the seeds at 1 d after imbibition started (DAI). Two TGACGT motifs at -445 and at -125 in the promoter region of the gene interacted with nuclear proteins from cotyledons of dry seeds and the activities were detected until 3 DAI. A transient assay with particle bombardment showed that the downstream region from -135 in the promoter was required for high level expression in the cotyledons and the activity was reduced by mutation of the TGACGT motif at -125. The activities to bind the TGACGT motifs were detected in the axes of the seeds at 1 DAI but disappeared at 4 DAI, although the mRNA for alpha-amylase in the axes appeared at 4 DAI and increased in level by 6 DAI. A transient assay experiment showed that a positive regulatory element for the expression in the axes was located in the region from -630 to -453. These results indicated that the TGACGT motif at -125 was required for high level expression of the gene in the cotyledons of the germinated seeds.

Effects of allogeneic bone marrow transplantation on recipient bone mineral density: A prospective study

Allogeneic bone marrow transplant (BMT) recipients have many known risk factors for developing decreased bone mineral density (BMD) after transplantation. We performed a prospective sequential evaluation of BMD in the lumbar spine and nondominant hip using dual-energy x-ray absorptiometry (DEXA) in a cohort of 47 adult patients (median age, 43 years) who were undergoing radiation-based BMT for hematologic malignancies. Baseline DEXA studies were performed before BMT and repeated at 3 to 4 months, 6 to 8 months, and 12 to 14 months after BMT. The majority of patients (60%) had been minimally treated with combination cytotoxic chemotherapy, having received no more than 1 treatment regimen before BMT. Graft-versus-host disease prophylaxis consisted of cyclosporine in combination with either methotrexate or prednisone, or both. Mean lumbar spine and hip BMD were normal before BMT (spine: 1.01 g/cm2, z score = 96%; hip: 0.86 g/cm2, z score = 100%) and gradually decreased (spine: 0.98 g/cm2, z score = 94%; hip: 0.76 g/cm2, z score = 91%) at 12 to 14 months. These declines were statistically significant (P < .006 and < .002 for lumbar spine; P < .001 and < .001 for hip). In addition, the sharpest decline occurred during the first 6 months after BMT and was more marked in the hip than the lumbar spine. These data suggest that BMT adversely affects BMD in this patient population.

Synthesis and degradation of a 28-kDa pod storage protein in french bean (Phaseolus vulgaris) plants

Pod storage protein (PSP) accumulated in developing pods of French bean (Phaseolus vulgaris L.) plants, and increasing the PSP mRNA level by pod removal resulted in the enhancement of PSP accumulation in pods that formed later. Pod storage protein was detected in flowers, young leaves and young stem internodes in addition to pods. Accumulation of PSP and its mRNA was induced by sink-removal in an organ-specific manner. In addition, wounding induced PSP accumulation systemically in leaves. Methyl jasmonate did not induce PSP synthesis but enhanced the synthesis that was induced by wounding. In senescing pods, PSP was degraded, and degradation products with molecular masses of 20 and 17 kDa were detected in the pods. The amount of 20-kDa degradation product was greater than that of the 17 kDa product.

Initial clinical experience evaluating Yttrium-90-chimeric T84.66 anticarcinoembryonic antigen antibody and autologous hematopoietic stem cell support in patients with carcinoembryonic antigen-producing metastatic breast cancer

cT84.66 is a human/murine IgG1 with high affinity and specificity for carcinoembryonic antigen (CEA). An earlier Phase I trial defined the maximum tolerated dose for 90Y-diethylenetriaminepentaacetic acid (DTPA)-cT84.66 at 22 mCi/m2. Dose-limiting toxicities were reversible leukopenia and thrombocytopenia. The purpose of this Phase I trial was to evaluate the feasibility and toxicities of administering higher activities of 90Y-DTPA-cT84.66 with stem cell support in patients with CEA-producing breast cancer. Patients with CEA-producing breast cancer refractory to standard therapies underwent peripheral stem cell collection followed by infusion of 111indium-DTPA-cT84.66. Those patients demonstrating tumor targeting received a single therapy dose of 90Y-DTPA-cT84.66, followed by Ca-DTPA infusion for 72 h posttherapy. Stem cells were reinfused following a divided schedule. To date, seven patients have been accrued to this trial. Each patient received an imaging dose of (111)In-cT84.66. Six patients demonstrated tumor imaging and received a single cycle of 90Y-cT84.66 at 15 mCi/m2 (three patients) and 22.5 mCi/m2 (three patients). One patient did not demonstrate tumor imaging and was not treated. At these administered activities, 90Y-cT84.66 was well tolerated. No dose-limiting toxicities have been observed. All patients demonstrated hematopoietic recovery after stem cell infusion. One patient demonstrated stable disease for 4 months; one patient had stable disease and reduction of bone pain for 3 months; and a third patient experienced >50% reduction of an ovarian metastasis, resolution of malignant pleural effusion, stable pleural metastases, and stable bone scan for 14 months. Preliminary results from this ongoing Phase I trial are promising and demonstrate the feasibility and potential for antitumor effects of stem cell supported 90Y-cT84.66 therapy in patients with CEA-producing breast cancers.

Dose escalation trial of indium-111-labeled anti-carcinoembryonic antigen chimeric monoclonal antibody (chimeric T84.66) in presurgical colorectal cancer patients

Chimeric T84.66 (cT84.66) is a high-affinity (1.16x10(11) M(-1)) IgG1 monoclonal antibody against carcinoembryonic antigen (CEA). The purpose of this pilot trial was to evaluate the tumor-targeting properties, biodistribution, pharmacokinetics and immunogenicity of 111In-labeled cT84.66 as a function of administered antibody protein dose.

METHODS

Patients with CEA-producing colorectal cancers with localized disease or limited metastatic disease who were scheduled to undergo definitive surgical resection were each administered a single intravenous dose of 5 mg of isothiocyanatobenzyl diethylenetriaminepentaacetic acid-cT84.66, labeled with 5 mCi of 111In. Before receiving the radiolabeled antibody, patients received unlabeled diethylenetriaminepentaacetic acid-cT84.66. The amount of unlabeled antibody was 0, 20 or 100 mg, with five patients at each level. Serial blood samples, 24-hr urine collections and nuclear images were collected until 7 days postinfusion. Human antichimeric antibody response was assessed up to 6 mo postinfusion.

RESULTS

Imaging of at least one known tumor site was performed in all 15 patients. Fifty-two lesions were analyzed, with an imaging sensitivity rate of 50.0% and a positive predictive value of 76.9%. The antibody detected tumors that were not detected by conventional means in three patients, resulting in a modification of surgical management. Interpatient variations in serum clearance rates were observed and were secondary to differences in clearance and metabolic rates of antibody and antibody:antigen complexes by the liver. Antibody uptake in primary tumors, metastatic sites and regional metastatic lymph nodes ranged from 0.4% to 134% injected dose/kg, resulting in estimated 90Y-cT84.66 radiation doses ranging from 0.3 to 193 cGy/mCi. Thirteen patients were evaluated 1-6 mo after infusion for human antichimeric antibody, and none developed a response. No major differences in tumor imaging, tumor uptake, pharmacokinetics or organ biodistribution were observed with increasing protein doses, although a trend toward increasing blood uptake and decreasing liver uptake was observed with increasing protein dose.

CONCLUSION

Chimeric T84.66 demonstrated tumor targeting comparable to other radiolabeled intact anti-CEA monoclonal antibodies. Its immunogenicity after single administration was lower than murine monoclonal antibodies. These properties make 111In-cT84.66, or a lower molecular weight derivative, attractive for further evaluation as an imaging agent. Yttrium-90 dosimetry estimates predict potentially cytotoxic radiation doses to select tumor sites, which makes 90Y-cT84.66 also appropriate for further evaluation in Phase I radioimmunotherapy trials. Although clinically important changes in biodistribution, pharmacokinetics and tumor targeting with increasing protein doses of 111In-cT84.66 were not demonstrated, the results do suggest that antibody clearance from the blood is driven by hepatic uptake and metabolism, with more rapid blood clearance seen in patients with liver metastases. These patients with rapid clearance and potentially unfavorable biodistribution for imaging and therapy may, therefore, be a more appropriate subset in which to evaluate the role of administering higher protein doses. This underscores the need to further identify, characterize and understand those factors that influence the biodistribution and clearance of radiolabeled anti-CEA antibodies, to allow for better selection of patients for therapy and rational planning of radioimmunotherapy.

Diffusion of piperacillin, cefotiam, minocycline, amikacin and ofloxacin into the prostate

BACKGROUND

The successful treatment of bacterial prostatitis depends on an effective antimicrobial concentration in prostatic tissue against the infecting organism. In this study we compared the diffusion of 5 types of antimicrobials into the prostate.

METHODS

The concentrations of piperacillin, cefotiam, minocycline, amikacin, and ofloxacin were determined in prostatic fluid, prostatic tissue, and serum 2.5 to 3 hours after a single administration from 55 patients with benign prostatic hypertrophy.

RESULTS

Although amikacin showed the highest mean concentration both in prostatic tissue and prostatic fluid, the prostatic tissue/serum ratio was significantly higher (P < 0.01) for ofloxacin (1.49 +/- 0.80) and minocycline (0.94 +/- 0.39) compared with those for amikacin (0.49 +/- 0.21) and piperacillin (0.21 +/- 0.15). Also, the prostatic fluid/serum ratio was lower than the prostatic tissue/serum ratio for each drug, however, the prostatic fluid/serum ratio of ofloxacin was significantly higher than that of other antimicrobials tested (P < 0.01).

CONCLUSION

These results support earlier studies demonstrating that fluoroquinolones are a useful class of antimicrobials for the treatment of chronic bacterial prostatitis. They also suggest that in view of the pharmacokinetic properties and antimicrobial activities, amikacin and minocycline may be alternate antimicrobial options for selected patients with bacterial infections of the prostate.

[A clinical study of arthroscopic cystectomy on popliteal cysts associated with rheumatoid arthritis]

PURPOSE

We performed a prospective study of arthroscopic cystectomy on popliteal cysts associated with rheumatoid arthritis.

MATERIALS

We performed arthroscopic cystectomy on three patients, four knees, and an open excision of a cyst on one patient, one knee, who had pain and swelling in the popliteal region. Of these five rheumatoid knees, three were grade I on the Larsen radiographic scale, one was II, and one was III. OPERATIVE METHOD: First, we performed synovectomy on the posterior compartment using a multi-portal approach. Second, we confirmed a small communication hole between the posterior compartment and the Popliteal cyst after the synovectomy with an angled arthroscope through the anterior compartment. Third, we enlarged the communication hole and performed a cystectomy (the excision of the membranous septum and the contents of the cyst) from the inside by using a motorized shaver. Finally, we performed a synovectomy on the anterior compartment. The follow-up period ranged from 1 year 6 months to 3 years, 4 months (the mean was 2 years, 4 months).

EVALUATION

We assessed the results using objective oriteria based on the evaluation of swelling, pain and subjective criteria based on the evaluation of the range of motion of the knee and confirmation of the disappearance of the cyst using MRI.

RESULT

We had good results in this study. All the four knees on which the arthroscopic cystectomy was performed had a reduction of pain and swelling right after the operation. The absence of the cyst was verified using MRI. We had no patient whose ROM was aggravated. However, synovitis and popliteal cysts reoccurred in one knee after the open excision (this case had the vasculitis, larsen grade III radiographically, and severe rheumatism).

DISCUSSION

The recurrence rate of the popliteal cyst was very high (over 50%) when a cyst was performed open exision using a posterior approach. Open synovectomy of an anterior compartment needed the manipulation in several cases because of limited knee movement. We had a reduction in pain and a disappearance of the cyst right after operation. Further more, there was no restriction in ROM resulting from this operative method.

CONCLUSION

Arthroscopic cystectomy is a superior procedure for treating the popliteal cysts associated with rheumatoid arthritis.

Clinical evaluation of indium-111-labeled chimeric anti-CEA monoclonal antibody

Chimeric T84.66 (cT84.66) is a high-affinity (1.16 x 10[11] M[-1]) IgG1 monoclonal antibody (MAb) against carcinoembryonic antigen (CEA). This pilot trial evaluated the tumor-targeting properties, biodistribution, pharmacokinetics and immunogenicity of 111In-labeled cT84.66.

METHODS

Patients with CEA-producing metastatic malignancies were administered a single intravenous dose of 5 mCi 111In-diethylenetriaminepentaacetic acid-cT84.66. Serial blood samples, 24-hr urine collections and nuclear images were collected up to 7 days postinfusion. Human antichimeric antibody response was assessed up to 6 mo postinfusion.

RESULTS

Imaging of at least one known tumor site was observed in 14 of 15 (93%) patients. Seventy-four lesions were analyzed with an imaging sensitivity rate of 45.1% and a positive predictive value of 94.1%. In one patient, two additional bone metastases developed within 6 mo of antibody administration at sites initially felt to be falsely positive on scan. One patient developed a human antichimeric antibody response predominantly to the murine portion of the antibody. The antibody cleared serum with a median T(1/2alpha) of 6.53 hr and a T(1/2beta) of 90.87 hr. Interpatient variations in serum clearance rates were observed and were secondary to differences in clearance and metabolic rates of antibody-antigen complexes by the liver. One patient demonstrated very rapid clearance of antibody by the liver, which compromised antibody localization to the primary tumor. Antibody uptake in primary and metastatic tumors ranged from 0.5% to 10.5% injected dose/kg, resulting in estimated radiation doses ranging from 0.97 to 21.3 cGy/mCi 90Y. Antibody uptake in regional lymph nodes ranged from 1.3% to 377% injected dose/kg, resulting in estimated radiation doses ranging from 2.0 to 617 cGy/mCi 90Y.

CONCLUSION

Chimeric T84.66 demonstrated tumor targeting that was comparable to that of other radiolabeled intact anti-CEA Mabs. Its immunogenicity after single administration was lower than murine Mabs. These properties make cT84.66 or a lower molecular weight derivative attractive for further evaluation as an imaging agent. These same properties also make it appropriate for future evaluation in Phase I therapy trials. Finally, a wide variation in the rate of antibody clearance was observed, with one patient demonstrating very slow clearance, resulting in the highest estimated marrow dose of the group, and one patient demonstrating unusually rapid clearance, resulting in poor antibody localization to tumor. Data from this study suggest that serum CEA levels, antibody-antigen complex clearance and, therefore, antibody clearance are influenced by both the production and clearance rates of CEA. This underscores the need to further identify, characterize and understand those factors that influence the biodistribution and clearance of radiolabeled anti-CEA antibodies to allow for better selection of patients for therapy and rational planning of radioimmunotherapy.

A case of leiomyosarcoma of the sphenoid sinus

A 43-year-old man with a primary leiomyosarcoma of the left sphenoid sinus is presented. To our knowledge, this is an unusual case of leiomyosarcoma, which has never been reported in the literature. Accurate and safe diagnosis was obtained by an endonasal endoscopic approach with minimal tissue invasion.

A 28-kilodalton pod storage protein of French bean plants. Purification, characterization, and primary structure

When French bean (Phaseolus vulgaris) plants were depodded in the early stages of fruit development, relative levels of a specific protein with a relative molecular weight of 28,000 were enhanced in the young pods that formed later. The protein, designated pod storage protein (PSP), was purified from extracts of newly formed pods from plants that had been previously depodded four times at intervals of 2 weeks. Two-dimensional polyacrylamide gel electrophoresis showed the presence of three forms (designated A, B, and C) of PSP with identical electrophoretic mobilities but different charges. The molecular mass of native PSP was estimated by gel filtration to be 67 kD; therefore, the protein was most likely present as a dimer. The antisera raised against forms A and C were crossreactive with each other. Form B lacked the N-terminal alanine of forms A and C. An expression library from French bean pods was screened using the antiserum against form A, and a full-length cDNA clone was isolated. The cDNA insert included 765 bp potentially encoding a polypeptide with 255 amino acid residues (and a calculated molecular mass of 28,854 D). The amino acid sequence deduced from the PSP cDNA had 65 to 71% identity with soybean (Glycine max) vegetative storage protein sequences (P.E. Staswick [1988] Plant Physiol 87: 250-254; and Correction [1989] Plant Physiol 89: 717). Genomic Southern blot analysis suggested that PSP is derived from a single-copy gene.

Promoter regions of cysteine endopeptidase genes from legumes confer germination-specific expression in transgenic tobacco seeds

Cysteine endopeptidases, SH-EP from Vigna mungo and EP-C1 from Phaseolus vulgaris, act to degrade seed storage protein during seed germination. Using transgenic tobacco plants, expression of SH-EP and promoter activity of the EP-C1 gene were analyzed in transgenic tobacco plants. The promoters of the two genes in tobacco seeds showed germination-specific activation, although post-translational processing of SH-EP and regulatory regions of promoter of the gene for EP-C1 were found to differ between leguminous seeds and transgenic tobacco seeds.

Promoter analysis of seed storage protein genes from Canavalia gladiata D.C

A number of A/T-rich sequences and a CATGCAT/A sequence are contained in the 5'-upstream regions of the genes encoding concanavalin A (Con A) and canavalin, two major seed storage proteins of Canavalia gladiata D.C. To study the role of these sequences in the seed-specific gene expression, we constructed 5'-deletion mutants and examined the transient expression of beta-glucuronidase reporter gene by particle bombardment and the stable expression by Agrobacterium-mediated transformation of tobacco plants. Positive regulatory elements were located in the -894/-602 and -602/-74 regions of the Con A gene, and in the -428/-376, -281/-155 and -155/-50 regions of the canavalin gene. In addition, the results suggested that the A/T-rich sequences in the 5'-upstream region of the Con A gene play a role in transcriptional activation, but that those of the canavalin gene have little effect on the gene expression. The CATGCAT/A sequence was not sufficient by itself for high levels of expression of both the Con A and canavalin genes. The canavalin polypeptide amounted to about 1% of the total extractable protein in the transgenic tobacco seeds, but the Con A polypeptide was not detected in the extractable protein.

Structure and expression of alpha-amylase gene from Vigna mungo

A single copy of the alpha-amylase gene, composed of three introns and four exons, was found in Vigna mungo. Examination of levels of alpha-amylase and its mRNA in detached cotyledons indicated that attachment of the embryonic axis is not required for expression of the gene in cotyledons of germinating seeds.

Expression of an Endopeptidase (EP-C1) in Phaseolus vulgaris Plants

Endopeptidase activity increases continually in pods of maturing fruits of French bean (Phaseolus vulgaris L. cv Goldstar) plants and is thought to participate in the protein mobilization in pods during the development of seeds (M. Endo, T. Minamikawa, D. Yamauchi, W. Mitsuhashi [1987] J Exp Bot 38: 1988-1995). In the present studies, one of the major endopeptidase forms, designated EP-C1, was purified as a 34-kD polypeptide from pods of maturing French bean fruits. EP-C1 was found to be immunologically distinguished from other forms in extracts from pods, but homologous to SH-EP, the major cysteine endopeptidase expressed in cotyledons of germinating Vigna mungo seeds (W. Mitsuhashi, T. Minamikawa [1989] Plant Physiol 89: 274-279). The level of endopeptidase that reacted with the antiserum to EP-C1 increased in pods as the fruit maturation proceeded. EP-C1 was also immunologically detected in stems of French bean plants bearing fruits of later maturation stages. Protein immunoblotting showed that a 34-kD polypeptide corresponding to EP-C1 in molecular mass occurred in extracts from 7- to 9-d cotyledons of germinating French bean seeds. In addition, two other polypeptides with slightly higher molecular masses were observed in extracts from 3- to 5-d cotyledons. We suggest that these two polypeptides are intermediates involved in posttranslational processing of EP-C1. RNA blot hybridization with EP-C1 cDNA as a probe showed that EP-C1 mRNA occurred in pods of fruits at later maturing stages and also in cotyledons of 3- to 7-d germinating seeds.

Intraoperative gamma detection probe with presurgical antibody imaging in colon cancer

In this study, presurgical gamma camera imaging and an intraoperative gamma detection probe were used in 12 consecutive patients 6 to 22 days after infusion with indium 111-labeled anticarcinoembryonic antigen monoclonal antibody (111In-MoAb). In three of 11 patients who underwent laparotomy, clinical management was affected by the probe findings: localization of occult retroperitoneal disease, identification of an occult cecal lesion, and localization of residual disease at a site of local recurrence. Of all intra-abdominal lesions seen using any method, the probe identified 18 (86%) of 21, compared with 14 (67%) of 21 with the 111In-MoAb scan, 10 (48%) of 21 by computed tomographic scan, and 16 (76%) of 21 after surgical exploration. Uptake of 111In-MoAb in the portal (n = 3) and mediastinal (n = 3) lymph nodes was not associated with histologic findings of malignant neoplasms. For all pathologically confirmed extrahepatic and nonportal sites of cancer, the probe localized nine of nine, compared with five of nine by 111In-MoAb scan, two of nine by computed tomographic scan, and six of nine by surgical exploration. Important clinical uses of the intraoperative probe included occult lesion identification, localization of areas with 111In uptake shown with MoAb scanning, and verification of complete resection of areas with 111In-MoAb uptake.

Stored mRNA in cotyledons of Vigna unguiculata seeds: nucleotide sequence of cloned cDNA for a stored mRNA and induction of its synthesis by precocious germination

By differential hybridization screening, we previously selected a class of cDNA clones from a lambda gt10 cDNA library that was constructed from the total poly(A)+ RNA of mature cowpea cotyledons (Plant Cell Physiol 31: 39-44, 1990). pSAS10, a clone of this class, hybridized with a cDNA probe complementary to poly(A)+ RNA from cotyledons collected 1 day after the onset of imbibition (DAI), but not with the cDNA probe from cotyledons at developmental stage II (13 to 15 days after flowering, DAF). pSAS10 mRNA was detectable only in cotyledons at developmental stage III (17 to 19 DAF) or later, and its level began to decline when seeds germinated. We have suggested that pSAS10 mRNA is likely to belong to the class of 'stored' mRNA or the mRNA that is formed at the late stage of seed maturation, is conserved in quiescent seeds and becomes functional at the early stage of germination. We determined the nucleotide sequence of pSAS10 cDNA consisting of 459 bp and an approximately 36 bp poly(A) tract, and deduced the amino acid sequence of its product, a 10-kDa cysteine-rich polypeptide. Synthesis of pSAS10 mRNA was induced just before germination began, not only in mature seeds but also in immature seeds even at stages I (9 to 11 DAF) and II (13 to 15 DAF) if they were placed under conditions suitable for germination.

[Effect of endothelin on gastric mucosal lesion in rats]

Gastric mucosal blood flow and gastric mucosal prostaglandin E2 (PGE2) and prostacyclin (PGI2) were investigated in male Wistar rats intraarterially injected with endothelin (ET), an endothelium-derived vasoconstrictor peptide. Immediately following ET (4 nmol/kg) administration, gastric mucosal blood flow decreased. Then 30 min later, the blood flow reached the minimum, but PGE2 and PGI2 showed the highest value. PGE2 showed a tendency to decrease 90 min later, while PGI2 continued to show high value. There were redness and hemorrhagic damage in the gastric mucosa. Endogenous PGs were presumed to be relate to the regulation of the development of the mucosal damage owing to decrease in the blood flow after ET administration.

Presurgical imaging with indium-labeled anti-carcinoembryonic antigen for colon cancer staging

Over a 4-year period, 108 patients with known or suspected colorectal cancer were studied by radioimmunoconjugate scintigraphy prior to operative procedures. Study subjects received 0.2 to 40 mg i.v. of murine anti-carcinoembryonic antigen monoclonal antibody labeled with 2-5 mCi of 111In (Indacea). Resected tissues were analyzed for 111In and carcinoembryonic antigen content. Tumor, liver, and draining lymph nodes had over 10% injected dose/kg compared to less than 2.5% injected dose/kg for other normal tissues. Primary tumors that were successfully imaged were significantly larger and had higher 111In and carcinoembryonic antigen content. In 54 patients, primary tumors were visualized with a sensitivity of 78%. Hepatic metastases (58 patients) were visualized as negative filling defects (sensitivity, 45%). Extrahepatic (intraabdominal) metastases (25 patients) were visualized (sensitivity, 48%) as areas of increased uptake. Extraabdominal metastases were uncommon (10 patients; sensitivity, 80%). Of 56 patients with known or suspected hepatic metastases who presented with no evidence of extrahepatic disease by conventional tests (X-ray, computerized tomographic scan), 20 (36%) were documented to have extrahepatic metastases at exploratory surgery and 10 of these (50%) had the extrahepatic disease localized by the Indacea scan. The management of these 10 patients was, or could have been, modified by the scan findings and unnecessary surgery eliminated.

Impact of radiolabeled antibody imaging on management of colon cancer

One hundred patients with known or suspected colorectal cancer were studied by radioimmunoconjugate scintigraphy prior to operation. Study subjects received murine monoclonal anticarcinoembryonic antigen labeled with indium 111 (Indacea). Sensitivity of imaging was 76 percent for primary tumors, 44 percent for hepatic metastases, 38 percent for extrahepatic abdominal metastases, and 78 percent for extraabdominal metastases. Seventeen of 46 patients (37 percent) with known or suspected hepatic metastases and no evidence of extrahepatic disease by conventional imaging methods had extrahepatic metastases at exploratory surgery. Nine of the 17 patients had disease accurately predicted by the Indacea scanning. The management of each of these nine patients was, or could have been, modified by the scan findings and unnecessary surgery eliminated. A number of patients without post-operative disease had an unexplained increase in plasma carcinoembryonic antigen level due to production of human antimouse antibody. The addition of excess mouse immunoglobulin to the plasma prior to assay blocked this artifactual increase.

cDNAs for canavalin and concanavalin A from Canavalia gladiata seeds. Nucleotide sequence of cDNA for canavalin and RNA blot analysis of canavalin and concanavalin A mRNAs in developing seeds

By a method of Escherichia coli expression-vector-primed cDNA synthesis, a cDNA expression library was constructed from total poly(A)-rich RNA that was prepared from immature embryos of Canavalia gladiata. Essentially full-length cDNA clones for two seed proteins, canavalin and concanavalin A, were selected from the library by immunological screening of the colonies and in vitro RNA synthesis and translation. The complete amino acid sequence of canavalin was determined from the nucleotide sequence of the corresponding cDNA and was found to be very homologous to 7S seed proteins of other legumes. The nucleotide sequence of the cDNA predicts a 26-amino-acid extension in the precursor at the amino terminus of the mature canavalin. Canavalin mRNA and concanavalin A mRNA levels at successive stages of the seed development were estimated by RNA blot hybridization and results indicated that the two mRNA levels are differently regulated.

Analysis of the effects of apomorphine and bulbocapnine in relation to the proposed dopamine receptor

On rat isolated vas deferens, apomorphine was found to be l/5th as active as dopamine. Reserpine or cocaine pretreatment failed to reduce the response to apomorphine. Low concentrations of apomorphine which do not cause contraction of the tissue, antagonize the effects of dopamine. The effects of dopamine were antagonized equally by phentolamine or apomorphine. On rabbit aortic strips 4 × 10−4M apomorphine repeated at 45 min intervals induces pronounced tachyphylaxis. During the tachyphylactic period dopamine was not inhibited to a significantly greater extent than was phenylephrine. Bulbocapnine tested against dopamine and phenylephrine yielded identical pA2 values of 6. Only at 10−5M was bulbocapnine observed to produce a preferentially greater blockade of dopamine. Dopamine or isoprenaline-induced relaxations of aortic strips were not blocked by bulbocapnine. Dopamine and 3 times 10−6M bulbocapnine increased the chronotropic effects in atria. Apomorphine and higher doses of bulbocapnine produced rate decelerating effects. On atria low doses of apomorphine were equally effective in reducing the effects of dopamine or histamine. These results are discussed in light of the proposal that the effects of apomorphine and bulbocapnine involve dopamine receptor interactions. In all three tissues there was no clear cut evidence of specific dopamine receptors.