Clinical Cancer Research AACR Conference on Cancer Prevention
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Cancer Research Clinical Cancer Research
Cancer Epidemiology Biomarkers & Prevention Molecular Cancer Therapeutics
Molecular Cancer Research Cancer Prevention Research
Cancer Prevention Journals Portal Cancer Reviews Online
Annual Meeting Education Book Meeting Abstracts Online
This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Henry, C. J.
Right arrow Articles by Siegall, C. B.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Henry, C. J.
Right arrow Articles by Siegall, C. B.
Clinical Cancer Research Vol. 11, 751-755, January 2005
© 2005 American Association for Cancer Research

Cancer Therapy: Preclinical

Clinical Evaluation of BR96 sFv-PE40 Immunotoxin Therapy in Canine Models of Spontaneously Occurring Invasive Carcinoma

Carolyn J. Henry1, Michael S. Buss2, Ingegerd Hellström4, Karl Erik Hellström4, William G. Brewer3, Jeffrey N. Bryan1 and Clay B. Siegall4

1 Departments of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri-Columbia, Columbia, Missouri; 2 Veterinary Clinical Sciences, Washington State University, Pullman, Washington; 3 Small Animal Surgery and Medicine, College of Veterinary Medicine, Auburn University, Auburn, Alabama; and 4 Bristol-Myers Squibb Pharmaceutical Research Institute, Seattle, Washington

Requests for reprints: Carolyn J. Henry, Departments of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri-Columbia, A373 Clydesdale Hall, 379 East Campus Drive, Columbia, MO 65211. Phone: 573-882-7821; Fax: 573-884-0705; E-mail: HenryC{at}missouri.edu.


   ABSTRACT
Top
 ABSTRACT
INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
Purpose: The immunotoxin BR96 sFv-PE40 is an effective antitumor agent against human breast and lung carcinoma xenografts in rodents. This study was designed to (a) determine the frequency with which canine carcinoma cells express Lewisy (Ley) antigen, thereby identifying canine carcinoma types suitable for the clinical evaluation of BR96 sFv-PE40, and (b) determine the safety and efficacy of BR96 sFv-PE40 in a canine model of spontaneously occurring cancers for investigation of targeted therapy.

Experimental Design: Carcinoma tissue samples were obtained from client-owned dogs presented for medical care. The tissues were assessed for Ley antigen expression using immunohistochemical methods. Dogs with tumors expressing Ley antigen were offered enrollment in a clinical trial to receive twice-weekly infusions of 4 to 12 mg/m2 BR96 sFv-PE40. Clinical toxicity and response data were assessed at each treatment.

Results: Twenty-two of 61 carcinomas evaluated were positive for Ley expression, including mammary, prostate, lung, and rectal carcinomas, and 12 dogs were enrolled in the clinical trial. The primary side effect was transient emesis. Partial responses or disease stabilization were noted in dogs with inflammatory mammary, bronchogenic, rectal, and tonsillar carcinoma. At least nine of the dogs developed antibodies to the immunotoxin after two to five infusions.

Conclusions: Although development of anti-BR96 sFv-PE40 antibodies limited the long-term effectiveness of this immunotoxin in dogs, rapid clinical responses in several aggressive canine carcinomas suggest the immunotoxin has utility for treatment of certain naturally occurring tumors and that its clinical evaluation for treatment of similar human carcinomas is warranted.

Key Words: inflammatory mammary carcinoma • immunotoxin • Lewisy antigen • animal model


   INTRODUCTION
Top
 ABSTRACT
 INTRODUCTION
MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
The mouse monoclonal antibody BR96 recognizes a Lewisy (Ley-related carbohydrate) antigen that is expressed by a variety of solid tumors as well as by normal gastrointestinal epithelium (1). After binding of BR96 to Ley at the cell surface, the monoclonal antibody internalizes into endosomes and lysosomes (2, 3). Immunoconjugates of BR96 and doxorubicin have been shown to possess strong antitumor activity in preclinical models (4, 5). Studies done in dogs showed that the dose-limiting toxicity of this immunoconjugate as well as of unconjugated BR96 is damage to the gastrointestinal epithelium. A doxorubicin conjugate using chimeric (mouse-human) BR96 has shown biological activity in humans, but the amount of conjugate that could be safely delivered because of the gastrointestinal toxicity has not been sufficient to justify its use as a single agent (6). However, there is a renewed clinical interest in this conjugate based on the finding in preclinical models that the therapeutic efficacy can be increased when the conjugate is combined with a taxane (7), and a phase II clinical trial of a BR96-doxorubicin conjugate in patients with advanced non–small cell lung carcinoma is ongoing.

A single-chain immunotoxin, BR96 sFv-PE40, has been genetically engineered by cloning the variable regions of BR96 and assembling them as a single chain (sFv), which was then fused with a truncated, nonbinding derivative of Pseudomonas exotoxin A (PE40) (8, 9). BR96 sFv-PE40 binds to Ley, is internalized, and translocates into the cytosol where it causes cell death via catalytic inhibition of protein synthesis. Previous studies have shown the immunotoxin to be an effective antitumor agent against human breast and lung carcinoma xenografts in rodents (8–10). The purpose of this study was 2-fold: (a) to determine the frequency with which canine carcinoma cells express Ley antigen, thereby identifying canine carcinoma types suitable for the clinical evaluation of BR96 sFv-PE40, and (b) to determine the safety and efficacy of BR96 sFv-PE40 in the treatment of naturally occurring carcinomas in dogs. The long-term goal of this study was to establish a large animal model of spontaneously occurring cancers for investigation of therapy with this novel immunotoxin.


   MATERIALS AND METHODS
Top
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
RESULTS
 DISCUSSION
 REFERENCES
 
Antigen Identification in Tissues
Carcinoma tissue samples were obtained from client-owned dogs presented for veterinary care at one of three referral veterinary oncology centers (Washington State University Veterinary Teaching Hospital, Auburn University Department of Small Animal Surgery and Medicine, and University of Missouri-Columbia Veterinary Medical Teaching Hospital). The biopsy specimens were immediately placed in OCT medium and frozen using liquid nitrogen. Tissue was stored (–80°C) overnight on dry ice before shipment for Ley expression analysis and indirect immunostaining. The peroxidase-antiperoxidase technique of Sternberger (11) was modified as described previously (1, 12) and used for immunostaining of tissue samples. The anti-Ley antibody was developed at Bristol-Myers Squibb (Syracuse, NY) and has been described previously (1). Frozen sections were prepared and treated with acetone before immunostaining. To decrease nonspecific background, sections were preincubated with normal dog serum diluted 1:5 in PBS. The mouse anti-Ley (BR96) monoclonal antibody to be tested, rabbit anti-mouse IgG (Sternberger-Meyer Immunochemicals, Inc., Jarrettsville, MD), and mouse peroxidase-antiperoxidase (Sternberger-Meyer Immunochemicals) were diluted in a medium containing 10% normal dog serum and 3% rabbit serum. Rabbit anti-mouse IgG was used at a dilution of 1:50. Mouse peroxidase-antiperoxidase containing 2 mg/mL specifically purified peroxidase-antiperoxidase was used at a dilution of 1:80. Each new batch of reagent was titrated to the most appropriate dilutions. A human breast carcinoma cell line (H3396) served as the positive control. Slides were evaluated by a medical doctor with considerable experience in immunohistology under code and regularly checked (also under code) by an independent investigator. Antigen expression was scored for homogeneity using a +/– scale and for degree of positive staining using a 0 to 4+ scale (0, no staining of any cells; 1+, staining of <30% of cells; 2+, staining of ≥30% to <50% of cells; 3+, staining of ≥50% to <75% of cells; 4+, staining of ≥75% of cells). Tumors that were homogenous and had a 3+ or greater score for Ley expression were considered positive for the presence of Ley antigen.

Clinical Evaluation in Dogs
Client-owned dogs undergoing surgical biopsy or excision of a carcinoma at the Washington State University Veterinary Teaching Hospital were screened for the study via immunostaining techniques described above. Inclusion criteria for eligible candidates included histopathologic confirmation of Ley-positive carcinoma and measurable tumor (primary or metastatic) remaining after surgery. In dogs 5 to 10, a specimen of normal colonic mucosa was obtained at the time of tumor biopsy such that immunostaining for Ley could be done. This was based on the hypothesis that the degree of Ley expression in normal gastrointestinal epithelium would correlate with the severity of gastrointestinal side effects associated with BR96 sFv-PE40 administration. Informed, signed owner consent and decline of standard-of-care therapy were required for study enrollment. No adjuvant therapy was permitted during study participation. Baseline evaluations included complete blood count, serum biochemical analysis, urinalysis, and complete tumor staging.

Assays for antibody formation against the immunotoxin were done using serum collected before each treatment with BR96 sFv-PE40. Serum samples from each dog were evaluated after the dog had received the first six doses of BR96 sFv-PE40 or when adverse reactions were noted and again at the time of study completion. Analysis of serum for presence of anti-immunotoxin antibodies was done by standard ELISA method as described previously (13). The study protocol did not require treatment discontinuation when antibody formation was detected unless adverse effects were clinically noted.

BR96 sFv-PE40 was diluted in 0.9% NaCl to a total volume of 10 mL and infused over 20 minutes on a Tuesday/Friday schedule. The planned protocol was for dogs to receive two 5-dose courses of BR96 sFv-PE40 with a 2-week rest period between courses. Routine patient monitoring consisted of serum biochemistry evaluation, complete blood count, and urinalysis repeated before treatments 3 and 5 and with every other treatment thereafter. Concurrent immunosuppressive therapy [dexamethasone 0.5 mg/kg i.v. 30 minutes before infusion and 24 hours later or anti-CTL-associated antigen 4 immunogobulin (CTLA4-Ig; Bristol-Myers Squibb) 10 mg/kg i.v. 30 minutes before infusion) was given to dogs enrolled later in the study after anti-immunotoxin antibody formation was noted as a consistent clinical problem developing in the first six dogs. The dose of BR96 sFv-PE40 ranged from 4 to 12 mg/m2 depending on date of entry into the study and whether colon immunoreactivity was used as a dose determinant. The first dog enrolled in the study was treated with two initial doses of 6 mg/m2 and then escalated to 12 mg/m2 based on the lack of clinical toxicity. In dogs for which colon immunoreactivity was determined (n = 5), BR96 sFv-PE40 was dosed as follows: 3 to 4+ immunoreactivity, 4 mg/m2; 2+, 6 mg/m2; 1+, 9 mg/m2; and 0, 12 mg/m2. Colonic biopsy sampling was discontinued after enrollment of these five dogs. This decision was made based on the clinical perception that Ley expression in normal gastrointestinal mucosa did not predict toxicity so that the risk of morbidity associated with colonic biopsy was not warranted. The final two dogs in the study were treated with 4 mg/m2 BR96 sFv-PE40 along with CTLA4-Ig as part of a protocol amendment intended to decrease the likelihood of anti-immunotoxin antibody formation. The combination protocol and dosage determinations were based on preclinical evaluation of CTLA4-Ig in laboratory monkeys and dogs.5

Response to therapy was assessed before each treatment using standard veterinary oncology response criteria (14). Tumor measurement was accomplished with techniques appropriate to tumor location. These techniques included thoracic radiography for evaluation of pulmonary metastasis, ultrasonography or computed tomography for internal masses, and caliper measurement of external masses. Complete response was defined as resolution of all clinical signs and absence of measurable tumor. Partial response was defined as a ≥50% decrease in tumor volume and no evidence of new metastases. Stable disease was defined as <50% decrease or 25% increase in tumor volume and no evidence of new metastatic lesions. Progressive disease was defined as an increase in tumor volume by ≥25% or the development of new metastatic lesions. Treatment was discontinued if disease progression or undesirable side effects occurred. Survival time was defined as the time from first histopathologic diagnosis until death or euthanasia due to tumor-related disease.


   RESULTS
Top
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
DISCUSSION
 REFERENCES
 
Sixty-one carcinoma samples were evaluated for presence of Ley antigen. Twenty-two tumors were positive according to the criteria given in MATERIALS AND METHODS. Carcinoma types expressing Ley included mammary (9 of 19), prostatic (3 of 7), bronchogenic (4 of 6), rectal (2 of 4), nasal (1 of 2), hepatic (1 of 3), tonsillar squamous cell carcinoma (1 of 1), lacrimal gland adenocarcinoma (1 of 1), and nasal planum squamous cell carcinoma (1 of 1). Carcinoma types in which Ley was not detected (score <3+) included thyroid (n = 5), transitional cell carcinoma of the urinary bladder (n = 3), biliary carcinoma (n = 2), perianal adenocarcinoma (n = 2), oral squamous cell carcinoma (n = 2), sweat gland carcinoma (n = 1), cutaneous carcinomatosis (n = 1), and carcinoma of unknown primary site (n = 1).

Of 22 dogs with carcinomas that expressed Ley, 10 met the eligibility criteria for clinical study enrollment. Tumor types in these 10 dogs included inflammatory mammary carcinoma (n = 3), rectal carcinoma (n = 2), bronchogenic carcinoma (n = 2), tonsillar squamous cell carcinoma (n = 1), nasal adenocarcinoma (n = 1), and lacrimal gland adenocarcinoma (n = 1). In addition to the dogs that met the inclusion criteria, two dogs (4 and 10) had tumors with heterogeneous or weak positive staining (1+) for Ley antigen and thus were ineligible for study enrollment. However, they were treated with BR96 sFv-PE40 on a compassionate-use basis at the owners' request. Their data were included in this report as the development of anti-immunotoxin antibodies became a substantial focus of this study and, as such, the information regarding antibody development in these dogs was considered to be of merit.

Side effects of therapy included transient febrile responses in 6 of 12 (50%) treated dogs and emesis in 3 of 12 (25%), all resolving within 24 hours. These side effects did not seem to be dose related. Episodes of emesis were short-lived in all affected dogs, and no biochemical evidence of organ toxicity affecting the pancreas was noted. Dog 3 experienced gall bladder necrosis, which necessitated a cholecystectomy. The excised tissue was examined with immunostaining and found strongly positive for Ley antigen. It is therefore possible that immunotoxin binding to the gall bladder epithelium led to necrosis, although this could not be confirmed in this case.

Response data are summarized in Table 1. No complete remissions were achieved. Partial response was achieved in three cases, including inflammatory mammary carcinoma (Fig. 1), tonsillar squamous cell carcinoma, and bronchogenic carcinoma (Fig. 2). The partial response seen in one of the dogs with inflammatory mammary carcinoma was first noted after only two infusions of BR96 sFv-PE40 (Fig. 1). Stable disease was observed in four cases, including rectal carcinoma (n = 2) and inflammatory mammary carcinoma (n = 2). Progressive disease occurred in three of the dogs (lacrimal gland adenocarcinoma, bronchogenic, and nasal carcinoma) that met the inclusion criteria. Both of the two dogs that did not meet the study criteria but were treated on a compassionate use basis had progressive disease in spite of therapy.


View this table:
[in this window]
[in a new window]
  		Table 1 Clinical outcome in 12 canine carcinoma patients treated with BR96 sFv-PE40

 


View larger version (126K):
[in this window]
[in a new window]
  		Fig. 1 Response of canine inflammatory mammary carcinoma to two doses of BR96 sFv-PE40. Left, pretreatment; right, post-treatment; arrow, identical reference point between two views. Tumor volume decreased by >50%. Surgical scar (right) due to cholecystectomy.

 


View larger version (79K):
[in this window]
[in a new window]
  		Fig. 2 Pretreatment (top) and post-treatment (bottom) computed tomography scans showing bronchogenic carcinoma lesion (arrow) in its widest diameter in a dog treated with 2.5 doses of BR96 sFv-PE40. Although this dog experienced >50% reduction in tumor volume as assessed by computed tomography, anti-immunotoxin antibody formation precluded further treatment.

 
Antibody titer data (positive, >1:10 or negative, <1:10) were available for all scheduled sample collection times in 11 of the 12 treated dogs. No dogs had pretreatment antibody titers and nine dogs produced antibodies to the PE40 portion of the BR96 sFv-PE40 fusion protein after two to five doses. In five of the first six dogs treated, disease stabilization or clinical response was noted until anti-immunotoxin antibody development occurred after which time the disease became progressive. In four subsequently enrolled dogs, concurrent treatment with dexamethasone did not prevent antibody formation. Finally, the treatment protocol was amended to include CTLA4-Ig as an immunosuppressive agent. Interestingly, both of the dogs treated with CTLA4-Ig developed anti-CTLA4-Ig antibodies rather than anti-immunotoxin antibodies. Timing of antibody formation is summarized in Table 1.


   DISCUSSION
Top
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
REFERENCES
 
In this study, immunostaining techniques were used to identify canine tumor types suitable for therapy with BR96 sFv-PE40. Of the canine carcinomas screened in this study, the types most likely to express Ley antigen were mammary, bronchogenic, and rectal carcinomas. The evaluation of Ley antigen expression in naturally occurring canine carcinomas is an important first step in establishing alternative animal models with which to assess the efficacy of novel Ley targeting therapies. In a review article addressing recombinant immunotoxin therapy, Pastan et al. (15) enumerated seven criteria that must be met to develop an immunotoxin for use in people. One of these criteria is that immunotoxin toxicity must be evaluated in animal models expressing the appropriated antigen. They further stated that this generally requires preclinical studies to be done in primates. Based on our identification of spontaneously occurring canine carcinomas that express Ley, it now seems reasonable that cancer-bearing dogs could serve as alternatives to primates for some preclinical studies.

Toxicity and efficacy of BR96 sFv-PE40 were evaluated not only for the obvious application to veterinary oncology but also because dog tumors may serve as models for similar malignancies in humans (16). Our results, albeit limited, were promising, especially for inflammatory mammary carcinoma in which one of three cases had a partial remission and two had disease stabilization. Inflammatory mammary carcinoma in dogs, as in women, is an extremely aggressive malignancy. In one review of 10 cases of canine inflammatory mammary carcinoma, all dogs had widespread metastatic disease at the time of diagnosis (17). Treatment is generally unrewarding, and most dogs are euthanatized shortly after diagnosis (17, 18) . The dramatic initial response noted with BR96 sFv-PE40 treatment in the responder with inflammatory mammary carcinoma was, unfortunately, abrogated when anti-immunotoxin antibodies developed. However, even partial remission for this tumor type with therapy other than radiation is quite encouraging.

As has been the case with other immunotoxins (19–22), antibody formation was a significant limitation to the successful long-term use of BR96 sFv-PE40 in the dogs enrolled in this study. Consistent with previous reports indicating that antibodies against immunotoxins generally develop within 2 weeks of exposure (20, 21), dogs in this study developed antibodies between 2 and 16 days of treatment initiation. In five of the first six dogs treated, disease stabilization or clinical response was noted until anti-immunotoxin antibody development occurred after which time the disease uniformly progressed. Although neutralization assays were not done as part of this study, a previous evaluation of BR96 sFv-PE40 in laboratory dogs indicated that rather than blocking cytotoxicity, development of anti-immunotoxin antibodies resulted in a more rapid clearance of the fusion protein, thus neutralizing the antitumor activity of the agent (13). This parallels what has been noted in people that develop anti-immunotoxin antibodies (21, 22). Treatment with immunosuppressive doses of dexamethasone did not prevent antibody formation. Administration of CTLA4-Ig, a compound that modulates T-cell activation via its inhibitory effects on the costimulatory molecule B7, was used in an attempt to block antibody formation. This genetically engineered product, a fusion protein of human CTLA4 and the IgG1-Fc region, was under preclinical investigation at the time of this study. Preliminary data in cynomolgus monkeys had indicated that a dosing regimen similar to that used in the current study was an effective method to suppress antibody formation. Whereas anti-immunotoxin antibodies were not detected in the two dogs treated with CTLA4-Ig, this was of little clinical significance in that they developed antibodies to the foreign fusion protein. The use of foreign proteins that may induce antibody formation is a challenge to developing successful immunotherapy approaches in both human and veterinary oncology. However, the ability to show proof of principle for novel agents in a model of spontaneously developing and inherently heterogeneous cancer is a strength of domestic animal translational research that cannot be duplicated in rodent models (16).

As evidenced by clinical responses in naturally occurring canine cancer, the unique binding and internalization of the BR96 antibody in carcinoma cells make this single-chain immunotoxin an interesting product candidate. Alternative approaches for use of this product in animal models may include combination with other therapies (e.g., administration of chemotherapeutic drugs), which may also decrease the immunogenicity of the immunotoxin. This study provides an example of translational cancer research using canine models of spontaneously occurring cancer to investigate promising therapies for use in both veterinary and human oncology.


   ACKNOWLEDGMENTS
 
We thank Ursula Garrigues for her assistance with immunostaining technique and interpretation.


   FOOTNOTES
 
Grant support: Bristol-Myers Squibb Pharmaceutical Research Institute (3005 First Avenue, Seattle, WA 98121).

The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

Note: M. Buss is currently at Veterinary Specialty Services, 1520 South Brentwood, Brentwood, Missouri. I. Hellström and K. Hellström are currently at Department of Pathology, Harborview Medical Center, Seattle, Washington. W. G. Brewer is currently at Affiliated Animal Care, Chesapeake, Virginia. and C. Siegall is currently at Seattle Genetics, Inc., Bothell, Washington.

5 Bristol-Myers Squibb Pharmaceutical Research Institute, unpublished data. Back

Received 8/ 1/04; revised 10/14/04; accepted 10/26/04.


   REFERENCES
Top
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 

  1. Hellström I, Garrigues HJ, Garrigues U, Hellström KE. Highly tumor-reactive, internalizing, mouse monoclonal antibodies to Le(y)-related cell surface antigens. Cancer Res 1990;50:2183–90.[Abstract/Free Full Text]
  2. Garrigues J, Anderson J, Hellström KE, Hellström I. Anti-tumor antibody BR96 blocks cell migration and binds to a lysosomal membrane glycoprotein on cell surface microspikes and ruffled membranes. J Cell Biol 1994;125:129–42.[Abstract/Free Full Text]
  3. Garrigues J, Garrigues U, Hellström I, Hellström KE. Ley specific antibody with potent anti-tumor activity is internalized and degraded in lysosomes. Am J Pathol 1993;142:607–22.[Abstract]
  4. Trail PA, Willner D, Lasch SJ, et al. Cure of xenografted human carcinomas by BR96-doxorubicin immunoconjugates. Science 1993;261:212–15.[Abstract/Free Full Text]
  5. Trail PA, Willner D, Bianchi AB, et al. Enhanced antitumor activity of Paclitaxel in combination with the anti-carcinoma immunoconjugate BR96-doxorubicin. Clin Cancer Res 1999;5:3632–8.[Abstract/Free Full Text]
  6. Hellström I, Hellström KE, Senter PD. Development and activities of the BR96-doxorubicin immunoconjugate. In: Hall WA, editor. Methods in Molecular Biology, Immunotoxin Methods and Protocols. Vol. 166. Totowa NJ: Humana Press Inc.; 2001. p. 3–16.
  7. Wahl AF, Donaldson KL, Mixan BJ, Trail PA, Siegall CB. Selective tumor sensitization to taxanes with the mAb-drug conjugate cBR96-doxorubicin. Int J Cancer 2001;93:590–600.[CrossRef][Medline]
  8. Friedman PN, McAndrew SJ, Gawlak SL, et al. BR96 sFv-PE40, a potent single-chain immunotoxin that selectively kills carcinoma cells. Cancer Res 1993;53:334–9.[Abstract/Free Full Text]
  9. Siegall CB, Chace D, Mixan B, et al. In vitro and in vivo characterization of BR96 sFv-PE40. A single-chain immunotoxin fusion protein that cures human breast carcinoma xenografts in athymic mice and rats. J Immunol 1994;152:2377–84.[Abstract]
  10. Friedman PN, Chace DF, Trail PA, Siegall CB. Antitumor activity of the single-chain immunotoxin BR96 sFv-PE40 against established breast and lung tumor xenografts. J Immunol 1993;150:3054–61.[Abstract]
  11. Sternberger LA. The unlabeled antibody peroxidase-antiperoxidase (PAP) method. In: Immunocytochemistry. New York: John Wiley and Sons, Inc.; 1979. p. 104–69.
  12. Garrigues HJ, Tilgen W, Hellström I, Franke W, Hellström KE. Detection of a human melanoma-associated antigen, p97, in histological sections of primary human melanomas. Int J Cancer 1982;29:511–5.[Medline]
  13. Siegall CB, Haggerty HG, Warner GL, et al. Prevention of immunotoxin-induced immunogenicity by coadministration with CTLA4-Ig enhances antitumor efficacy. J Immunol 1997;159:5168–73.[Abstract]
  14. Chun R, Garrett L, MacEwen EG. Cancer chemotherapy. In: Withrow SJ, MacEwen EG, editors. Small animal clinical oncology. 3rd ed. Philadelphia: WB Saunders Co.; 2001. p. 92–118.
  15. Pastan I, Pai LH, Brinkman U, FitzGerald D. Recombinant immunotoxins. Breast Cancer Res Treat 1996;38:3–9.[CrossRef][Medline]
  16. Vail DM, MacEwen EG. Spontaneously occurring tumors of companion animals as models for human cancer. Cancer Invest 2000;18:781–92.[Medline]
  17. Susaneck SJ, Allen TA, Hoopes J, Withrow SJ, Macy DW. Inflammatory mammary carcinoma in the dog. J Am Anim Hosp Assoc 1983;19:971–6.
  18. Perez-Alenza MD, Tabanera E, Pena L. Inflammatory mammary carcinoma in dogs: 33 cases (1995–1999). J Am Vet Med Assoc 2001;219:1110–4.[CrossRef][Medline]
  19. Pai LH, Pastan I. Immunotoxin therapy for cancer. J Am Med Assoc 1993;269:78–81.[CrossRef][Medline]
  20. Pastan I, FitzGerald D. Recombinant toxins for cancer treatment. Science 1991;254:1173–7.[Abstract/Free Full Text]
  21. Pai LH, Bookman MA, Ozols RF, et al. Clinical evaluation of intraperitoneal Pseudomonas exotoxin immunoconjugate OVB3-PE in patients with ovarian cancer. J Clin Oncol 1991;9:2095–103.[Abstract]
  22. Frankel AE, Kreitman RJ, Sausville EA. Targeted toxins. Clin Cancer Res 2000;6:326–34.[Abstract/Free Full Text]



This article has been cited by other articles:


Home page
 Cancer Res.Home page
T. Wang, J. Zhao, J.-L. Ren, L. Zhang, W.-H. Wen, R. Zhang, W.-W. Qin, L.-T. Jia, L.-B. Yao, Y.-Q. Zhang, et al.
Recombinant Immunoproapoptotic Proteins with Furin Site Can Translocate and Kill HER2-Positive Cancer Cells
Cancer Res., December 15, 2007; 67(24): 11830 - 11839.
[Abstract] [Full Text] [PDF]

Home page
 Cancer Res.Home page
M. Schuster, P. Umana, C. Ferrara, P. Brunker, C. Gerdes, G. Waxenecker, S. Wiederkum, C. Schwager, H. Loibner, G. Himmler, et al.
Improved Effector Functions of a Therapeutic Monoclonal Lewis Y-Specific Antibody by Glycoform Engineering
Cancer Res., September 1, 2005; 65(17): 7934 - 7941.
[Abstract] [Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Henry, C. J.
Right arrow Articles by Siegall, C. B.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Henry, C. J.
Right arrow Articles by Siegall, C. B.

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Cancer Research Clinical Cancer Research
Cancer Epidemiology Biomarkers & Prevention Molecular Cancer Therapeutics
Molecular Cancer Research Cancer Prevention Research
Cancer Prevention Journals Portal Cancer Reviews Online
Annual Meeting Education Book Meeting Abstracts Online