PI3K Pathway: A Potential Ovarian Cancer Therapeutic Target?

…[T]here are several PI3K signaling pathway targeting drugs in clinical development for use against ovarian cancer and solid tumors, including GDC-0941, BEZ235, SF1126, XL-147, XL-765, BGT226, and PX-866.  The results of two recent medical studies suggest that the use of PI3K-targeted therapies may offer an effective therapeutic approach for patients with advanced-stage and recurrent ovarian cancer, including a generally chemotherapy-resistant histological subtype of epithelial ovarian cancer known as “ovarian clear cell cancer” (OCCC).  The targeting of the PI3K pathway in endometrial, ovarian, and breast cancer is also being investigated by a Stand Up To Cancer “Dream Team.” …

PI3K Cellular Signaling Pathway — An Overview

PI3K/AKT cellular signaling pathway (Photo: Cell Signaling Technology(R))

In 2004 and 2005, multiple researchers identified mutations in the PIK3CA  gene with respect to multiple cancers.[1]  The PIK3CA gene encodes the PI3K catalytic subunit p110α. PI3K (phosphoinositide 3- kinase) proteins have been identified in crucial signaling pathways of ovarian cancer cells. PI3Ks are also part of the PI3K-AKT-mTOR signaling pathway which promotes cellular glucose metabolism, proliferation, growth, survival, and invasion and metastasis in many cancers. PIK3CA gene mutations can increase PI3K signaling, thereby activating the PI3K-AKT-mTOR pathway within cancer cells.

As of this writing, there are several PI3K signaling pathway targeting drugs in clinical development for use against ovarian cancer and solid tumors, including GDC-0941, BEZ235, SF1126, XL-147, XL-765, BGT226, and PX-866. [2]  The results of two recent medical studies suggest that the use of PI3K-targeted therapies may offer an effective therapeutic approach for patients with advanced-stage and recurrent ovarian cancer, including a generally chemotherapy-resistant histological subtype of epithelial ovarian cancer known as “ovarian clear cell cancer” (OCCC).  The targeting of the PI3K pathway in endometrial, ovarian, and breast cancer is also being investigated by a Stand Up To CancerDream Team.”

Frequent Mutation of PIK3CA Gene In Recurrent & Advanced Clear Cell Ovarian Cancer

OCCC is one of the five major subtypes of epithelial ovarian cancer. OCCC accounts for only 4% to 12% of epithelial ovarian cancer in Western countries and, for unknown reasons, it comprises more than 20% of such cancers in Japan [3,4,5]. OCCC possesses unique clinical features such as a high incidence of stage I disease, a large pelvic mass, an increased incidence of venous thromboembolic complications, and hypercalcemia. It is frequently associated with endometriosis.  Compared to serous ovarian cancer, OCCC is relatively resistant to conventional platinum and taxane-based chemotherapy. For these reasons, new effective therapies are desperately needed for OCCC.

Researchers from Johns Hopkins and the University of California, Los Angeles (UCLA) analyzed 97 OCCC tumors for genetic sequence mutations in KRAS (v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog), BRAF (v-raf murine sarcoma viral oncogene homolog B1), PIK3CA (phosphoinositide-3-kinase, catalytic, alpha polypeptide), TP53 (tumor protein p53), PTEN (phosphatase and tensin homolog), and CTNNB1 (Catenin, Beta-1) as these mutations frequently occur in other major types of ovarian cancers.[6] The samples tested included the following:

  • 18 OCCCs for which affinity-purified tumor cells from fresh specimens were available;
  • 10 OCCC tumor cell lines.

Upon test completion, the researchers discovered that sequence mutations of PIK3CA, TP53, KRAS, PTEN, CTNNB1, and BRAF occurred in 33%, 15%, 7%, 5%, 3%, and 1% of OCCC cases, respectively.

Clear cell carcinoma of the ovary (Photo: Geneva Foundation For Medical Education & Research)

The sequence analysis of the 18 affinity purified OCCC tumors and the 10 OCCC cell lines showed a PIK3CA mutation frequency of 46%. Based upon these findings the researchers concluded that the use of PIK3CA-targeting drugs may offer a more effective therapeutic approach compared with current chemotherapeutic agents for patients with advanced-stage and recurrent OCCC. As noted above, there are several PI3K-targeting drugs in clinical development for use against ovarian cancer and solid tumors.[2]

Notably, one of the researchers involved with this OCCC study is Dennis J. Slamon, M.D., Ph.D. Dr. Slamon serves as the Director of Clinical/Translational Research, and as Director of the Revlon/UCLA Women’s Cancer Research Program at the Jonsson Comprehensive Cancer Center. Dr. Slamon is also a professor of medicine, chief of the Division of Hematology/Oncology and Executive Vice Chair of Research for UCLA’s Department of Medicine. Dr. Slamon is a co-discoverer of the breast cancer drug Herceptin®. Herceptin is a monoclonal antibody targeted therapy used against HER-2 breast cancer, an aggressive breast cancer subtype that affects 20% to 30% of women with the disease. Herceptin’s development was based, in part, upon the unique genetic profile of HER-2 breast cancer as compared to other forms of breast cancer. Herceptin® revolutionized the treatment of HER-2 postive breast cancer and is recognized worldwide as the standard of care for that subtype of breast cancer.  The approach taken by Johns Hopkins and UCLA researchers in this study — the identification of  a subtype within a specific form of cancer that may be susceptible to a targeted therapy —  bears a striking similarity to the overarching approach taken in the development of Herceptin®.

Ovarian Cancer & Other Solid Tumors With PIK3CA Gene Mutations Respond To PI3K-AKT-mTOR Pathway Inhibitors In Phase I Clinical Testing.

Testing patients with cancer for PIK3CA gene mutations is feasible and may allow targeted treatment of the PI3K-AKT-mTOR cellular signaling pathway, according to the results of a University of  Texas, M.D. Anderson Cancer Center study presented on November 17, 2009 at the 2009 AACR (American Association for Cancer Research)-NCI (National Cancer Institute)-EORTC (European Organization For Research & Treatment of Cancer) International Conference on Molecular Targets and Cancer Therapeutics.[7]

mTOR cellular signaling pathway (Photo: Cell Signaling Technology(R))

Filip Janku, M.D., Ph.D, a clinical research fellow with the M.D. Anderson Cancer Center’s department of investigational cancer therapeutics, and colleagues conducted a mutational analysis of exon 9 and exon 20 of the PI3KCA gene using DNA from the tumors of patients referred to targeted therapy clinical trials. Patients with PIK3CA mutations were preferably treated whenever possible with regimens utilizing PI3K-AKT-mTOR signaling pathway inhibitors.

As part of this study 117 tumor samples were analyzed. PIK3CA mutations were detected in 14 (12%) patients.  In tumor types with more than 5 patients tested, PIK3CA mutations were identified in endometrial cancer (43%, 3 out of 7 patients), ovarian cancer (22%, 5 out of 23 patients), squamous head and neck cancer (14%, 1 out of 7 patients), breast cancer (18%, 2 out of 11 patients), and colon cancer (15%, 2 out of 13 patients). No mutations were identified in patients with melanoma or cervical cancer.

Of the 14 patients found to possess PIK3CA mutations, 10 were treated based upon a clinical trial protocol that included a drug targeting the PI3K-AKT-mTOR pathway.  A partial response to treatment was experienced by 4 (40%) patients. Although the total number of patients is small, there were 2 (67%) patient responses in 3 endometrial cancer cases, 1 (25%) patient response in 4 ovarian cancer cases, 1 (100%) patient response in 1 breast cancer, and no patient response in 1 colorectal cancer case.  Although the total number of study patients is small, the researchers conclude that the response rate appears high (40%) in tumors with PIK3CA mutations treated with PI3K-AKT-mTOR pathway inhibitors.

“The implications of this study are twofold,” said Dr. Janku.  “We demonstrated that PIK3CA testing is feasible and may contribute to the decision-making process when offering a patient a clinical trial. Although this study suffers from low numbers, the response rate observed in patients treated with inhibitors of PI3K/AKT/mTOR pathway based on their mutational status was well above what we usually see in phase-1 clinical trials.”  “These results are intriguing but at this point should be interpreted with caution,” said Janku. “The promising response rate needs to be confirmed in larger groups of patients. We expect to learn more as this project continues to offer PIK3CA screening to patients considering a phase-1 clinical trial.”

Stand Up 2 Cancer Dream Team: Targeting the PI3K Pathway in Women’s Cancers

The potential importance of the PI3K pathway in the treatment of ovarian cancer is emphasized by the two medical studies above.  This issue is also receiving considerable attention from one of the Stand Up 2 Cancer (SU2C) “Dream Teams,” which is going to evalute  the potential for targeting the PI3K pathway in women’s cancer.  SU2C assigned $15 million of cancer research funding to this critical issue.  The scientists involved in this SU2C Dream Team are the pioneers who discovered the PI3K pathway and validated its role in human cancers, and they will focus on breast, ovarian and endometrial cancers, all of which possess the PI3K mutation.

The leader and co-leaders of the PI3K pathway SU2C team are set forth below.

Leader:

Lewis C. Cantley, Ph.D., Director, Cancer Center at Beth Israel Deaconess Medical Center.

Co-Leaders:

Charles L. Sawyers, M.D., Director, Human Oncology and Pathogenesis Program, Memorial Sloan-Kettering Cancer Center.

Gordon B. Mills, M.D., Ph.D., Chair, Department of Systems Biology, University of Texas, M.D. Anderson Cancer Center.

The specific SU2C Dream Team research goal with respect to targeting the PI3K pathway in women’s cancers is stated as follows:

The PI3K pathway is mutated in more cancer patients than any other, and these mutations are the most frequent events in women’s cancers, making it an attractive molecular target for agents that inhibit these genetic aberrations. If successful, this project will allow clinicians to use biomarkers and imaging techniques to predict which patients will benefit from PI3K pathway inhibitors and lead to the development of therapeutic combinations that will hit multiple targets in the complex pathways that contribute to cancer cell growth.  This work will help assure that these therapies are given to patients who will benefit from them, and it will also increase the overall pace of clinical trials targeting PI3K inhibitors.

Based upon the two studies discussed, and the creation and funding of the SU2C Dream Team for the purpose of targeting the PI3K pathway in women’s cancer, the future holds great promise in the battle against ovarian cancer (including OCCC).  It is our hope that more clinical study investigators will offer PI3K pathway mutation screening to all ovarian cancer patient volunteers.  Libby’s H*O*P*E*™ will continue to monitor the clinical development of PI3K pathway inhibitors, and make our readers aware of all future developments.

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References:

1/Yuan TL, Cantley LC. PI3K pathway alterations in cancer: variations on a theme. Oncogene. 2008 Sep 18;27(41):5497-510. PubMed PMID: 18794884
Samuels Y, Ericson K. Oncogenic PI3K and its role in cancer. Curr Opin Oncol. 2006 Jan;18(1):77-82. PubMed PMID: 16357568.
Levine DA, Bogomolniy F, Yee CJ, et. al. Frequent mutation of the PIK3CA gene in ovarian and breast cancers. Clin Cancer Res. 2005 Apr 15;11(8):2875-8. PubMed PMID: 15837735.
Samuels Y, Wang Z, Bardelli A, et. al. High frequency of mutations of the PIK3CA gene in human cancers. Science. 2004 Apr 23;304(5670):554. Epub 2004 Mar 11. PubMed PMID: 15016963.

2/For open ovarian cancer clinical trials using a PI3K-targeted therapy; CLICK HERE; For open solid tumor clinical trials using a PI3K-targeted therapy, CLICK HERE.

3/ Itamochi H, Kigawa J & Terakawa N.  Mechanisms of chemoresistance and poor prognosis in ovarian clear cell carcinoma. Can Sci 2008 Apr;99(4):653-658. [PDF Document]

4/Schwartz DR, Kardia SL, Shedden KA, et. alGene Expression in Ovarian Cancer Reflects Both Morphology and Biological Behavior, Distinguishing Clear Cell from Other Poor-Prognosis Ovarian CarcinomasCan Res 2002 Aug; 62, 4722-4729.

5/Sugiyama T & Fujiwara K.  Clear Cell Tumors of the Ovary – Rare Subtype of Ovarian Cancer, Gynecologic Cancer, American Society of Clinical Oncology (ASCO) Educational Book, 2007 ASCO Annual Meeting, June 2, 2007 (Microsoft Powerpoint presentation).

6/Kuo KT, Mao TL, Jones S, et. al. Frequent Activating Mutations of PIK3CA in Ovarian Clear Cell Carcinoma. Am J Pathol. 2009 Apr 6. [Epub ahead of print]

7/Janku F, Garrido-Laguna I, Hong D.S.  PIK3CA mutations in patients with advanced cancers treated in phase I clinical trials, Abstract #B134, Molecular Classification of Tumors, Poster Session B, 2009 AACR-NCI-EORTC Molecular Targets and Cancer Therapeutics Conference. [PDF Document].

M.D. Anderson’s EphA2-Targeted Therapy Delivers Chemo Directly to Ovarian Cancer Cells

With a novel therapeutic delivery system, a research team led by scientists at The University of Texas M. D. Anderson Cancer Center has successfully targeted a protein that is over-expressed in ovarian cancer cells. Using the EphA2 protein as a molecular homing mechanism, chemotherapy was delivered in a highly selective manner in preclinical models of ovarian cancer, the researchers report in the July 29 issue of the Journal of the National Cancer Institute. … In the models, the therapy inhibited tumor growth in treated mice by 85 percent – 98 percent compared to control mice. … [Anil] Sood said, “We are gearing up to bring it to phase I clinical trials. A lot of the safety studies are well under way or nearing completion and we anticipate that this drug will enter clinical trials within the next few months.”

M. D. Anderson-led team finds potent antitumor activity with a monoclonal antibody-chemotherapy combination

With a novel therapeutic delivery system, a research team led by scientists at The University of Texas M. D. Anderson Cancer Center has successfully targeted a protein that is over-expressed in ovarian cancer cells. Using the EphA2 protein as a molecular homing mechanism, chemotherapy was delivered in a highly selective manner in preclinical models of ovarian cancer, the researchers report in the July 29 issue of the Journal of the National Cancer Institute.

EphA2 is attractive for such molecularly targeted therapy because it has increased expression in ovarian and other cancers, including breast, colon, prostate and non-small cell lung cancers and in aggressive melanomas, and its expression has been associated with a poor prognosis.

Anil K. Sood, M.D., professor and in the Departments of Gynecologic Oncology and Cancer Biology at the Univ. of Texas M. D. Anderson Cancer Center

Anil K. Sood, M.D., professor in the Departments of Gynecologic Oncology and Cancer Biology at the Univ. of Texas M. D. Anderson Cancer Center

“One of our goals has been to develop more specific ways to deliver chemotherapeutic drugs,” said senior author Anil K. Sood, M.D., professor and in the Departments of Gynecologic Oncology and Cancer Biology at M. D. Anderson. “Over the last several years we have shown that EphA2 is a target that is present quite frequently in ovarian and other cancers, but is either present in low levels or is virtually absent from most normal adult tissues. EphA2’s preferential presence on tumor cells makes it an attractive therapeutic target.”

The researchers used a carrier system to deliver chemotherapy directly to ovarian cancer cells. The immunoconjugate contains an anti-EphA2 monoclonal antibody linked to the chemotherapy drug monomethyl auristatin phenylalanine (MMAF) through the non-cleavable linker maleimidocaproyl. Research has shown that auristatins induce cell cycle arrest at the G – M border, disrupt microtubules and induce apoptosis (programmed cell death) in cancer cells.

The investigators evaluated the delivery system’s specificity in EphA2-positive HeyA8 and EphA2-negative SKMel28 ovarian cancer cells through antibody-binding and internalization assays. They also assessed viability and apoptosis in ovarian cancer cell lines and tumor models and examined anti-tumor activity in orthotopic mouse models with mice bearing HeyA8-luc and SKOV3ip1 ovarian tumors.

According to Sood, who is also co-director of both the Center for RNA Interference and Non-Coding RNA and the Blanton-Davis Ovarian Cancer Research Program at M. D. Anderson, the immunoconjugate was highly specific in delivering MMAF to the tumor cells that expressed EphA2 while showing minimal uptake in cells that did not express the protein. In the models, the therapy inhibited tumor growth in treated mice by 85 percent – 98 percent compared to control mice.

“Once we optimized the dosing regimen, the drug was highly effective in reducing tumor growth and in prolonging survival in preclinical animal models,” Sood said. “We actually studied bulkier masses because that is what one would see in a clinical setting where there are pre-existent tumors, and even in this setting the drug was able to reduce or shrink the tumors.”

As for future research with the EphA2-silencing therapy, Sood said, “We are gearing up to bring it to phase I clinical trials. A lot of the safety studies are well under way or nearing completion and we anticipate that this drug will enter clinical trials within the next few months.”

He added that his group is simultaneously conducting preclinical testing on other chemotherapy drugs to determine which agents might combine well with the immunoconjugate used in the current study.

“There is growing interest in molecularly targeted therapy so that we are not indiscriminately killing normal cells,” Sood noted. “The goal is to make the delivery of chemotherapy more specific. The immunoconjugate we used is in a class of drugs that is certainly quite attractive from that perspective.”

Research was funded by NCI-DHHS-NIH T32 Training Grant (T32 CA101642 to A.M.N.). This research was funded in part by support from M. D. Anderson’s ovarian cancer SPORE grant (P50 CA083639), the Marcus Foundation, the Gynecologic Cancer Foundation, the Entertainment Industry Foundation, the Blanton-Davis Ovarian Cancer Research Program, and Sood’s Betty Ann Asche Murray Distinguished Professorship.

Co-authors with Sood are Jeong-Won Lee, Hee Dong Han, Mian M. K. Shahzad, Seung Wook Kim, Lingegowda S. Mangala, Alpa M. Nick, Chunhua Lu, Rosemarie Schmandt, Hye-Sun Kim, Charles N. Landen, Robert L. Coleman, all of M. D. Anderson’s Department of Gynecologic Oncology; Robert R. Langley, of M. D. Anderson’s Department of Cancer Biology; Jeong-Won Lee, also of the Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; Mian M. K. Shahzad, also of the Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, Texas; Hye-Sun Kim, also of the Department of Pathology, Cheil General Hospital and Women’s Healthcare Center, Kwandong University College of Medicine, Seoul, Korea; and Shenlan Mao, John Gooya, Christine Fazenbaker, Dowdy Jackson, and David Tice , all of MedImmune, Inc., Gaithersburg, Maryland.

Source: EphA2-Targeted Therapy Delivers Chemo Directly to Ovarian Cancer Cells – M. D. Anderson-led team finds potent antitumor activity with a monoclonal antibody-chemotherapy combination, M.D. Anderson News Release, 29 Jul. 09 [summarizing the findings of Lee JW, Han HD, Shahzad MM et. al. EphA2 Immunoconjugate as Molecularly Targeted Chemotherapy for Ovarian Carcinoma. J Natl Cancer Inst. 2009 Jul 29. [Epub ahead of print]].

Preclinical Results Validate Lpathomab As A Potential Future Treatment for Ovarian Cancer

“Lpath, Inc. … , the category leader in bioactive-lipid-targeted therapeutics, reported compelling new in vivo and in vitro results relating to its preclinical drug candidate, Lpathomab, in various ovarian cancer studies …”

“Lpath Presents Compelling New Preclinical Results of Its Anti-Cancer Drug Candidate, Lpathomab(TM), at the AACR 100th Annual Meeting –

New In Vivo and In Vitro Results Provide Further Validation of Lpathomab as Potential Treatment for Cancer

SAN DIEGO, CA, Apr 20, 2009 (MARKET WIRE via COMTEX)Lpath, Inc. (OTCBB: LPTN), the category leader in bioactivelipid-targeted therapeutics, reported compelling new in vivo and in vitro results relating to its preclinical drug candidate, Lpathomab, in various ovarian cancer studies. The results were presented today by Lpath scientists at the 100th Annual Meeting of the American Association for Cancer Research (AACR) in Denver, Colorado.

Lpathomab is a monoclonal antibody that binds to the bioactive lipid lysophosphatidic acid (LPA) and acts as a molecular sponge to absorb LPA, thereby neutralizing LPA-mediated biological effects on tumor growth, angiogenesis, and metastasis. LPA has been associated with a variety of cancer types, but the correlation with ovarian cancer and breast cancer has been particularly strong.

Using the human ovarian cell line called SKOV3, Lpath’s preclinical studies demonstrated Lpathomab significantly reduced IL-8 and IL-6 cytokine release in SKOV3-conditioned media and blocked tumor-cell migration triggered by LPA (both IL-8 and IL-6 promote tumor angiogenesis and metastasis). More important, Lpathomab inhibited the progression of SKOV3 tumor cells when injected into the peritoneal cavity of mice and reduced levels of pro-metastatic factors in these animals.

Lpathomab also reduced neovascularization (new blood-vessel growth) in two classical angiogenic models and showed preliminary anti-metastatic activity when tested in a classical experimental metastasis model.

According to Roger Sabbadini, Ph.D., Lpath’s founder and chief scientific officer, ‘In view of these promising preclinical results, we believe Lpathomab has the potential to augment the efficacy of current ovarian cancer therapy by blocking the growth-promoting, angiogenic, and metastatic effects of LPA.’

About Lpath

San-Diego-based Lpath, Inc. is the category leader in bioactive-lipid-targeted therapeutics, an emerging field of medical science whereby bioactive signaling lipids are targeted for treating important human diseases. ASONEP(TM), an antibody against Sphingosine-1-Phosphate (S1P), is currently in a Phase 1 clinical trial in cancer patients and also holds promise against multiple sclerosis and various other disorders. ASONEP is being developed with the support of partner Merck-Serono as part of a worldwide exclusive license. A second product candidate, iSONEP(TM) (the ocular formulation of the S1P antibody), has demonstrated superior results in various preclinical models of age-related macular degeneration (AMD) and retinopathy and is in a Phase 1 clinical trial in wet-AMD patients. Lpath’s third product candidate, Lpathomab(TM), is an antibody against lysophosphatidic acid (LPA), a key bioactive lipid that has been long recognized as a valid disease target (cancer, neuropathic pain, fibrosis). The company’s unique ability to generate novel antibodies against bioactive lipids is based on its ImmuneY2(TM) drug-discovery engine, which the company is leveraging as a means to expand its pipeline. For more information, visit www.Lpath.com …”

Sources:

New Monoclonal Antibody Offers Hope In the Fight Against Ovarian Cancer

“Kellogg, an associate professor of pathology and laboratory medicine at the Brody School of Medicine at [East Carolina University] ECU, created the antibody, called DS-6, that attaches to cancer cells in her laboratory at ECU. DS-6 will serve as a delivery vehicle for a highly potent cell-killing agent developed by ImmunoGen specifically for delivery to cancer cells by antibodies. The antibody latches on to tumor cells and enables the whole compound – the antibody and the attached cell-killing agent – to enter the cancer cell. Once inside, the cell-killing agent becomes activated and kills the tumor cell as it divides.”

“A discovery by an East Carolina University pathologist might be a breakthrough in an evolving class of drugs used to fight cancer.

Dr. Anne Kellogg has developed a monoclonal antibody that could play a vital role in treating the most common form of ovarian cancer, breast cancer and other cancers. She is working with two major drug firms, ImmunoGen Inc. and sanofi-aventis, that have expertise in formulating antibodies into cancer therapies and taking them to clinical trials in humans.

Kellogg, an associate professor of pathology and laboratory medicine at the Brody School of Medicine at ECU, created the antibody, called DS-6, that attaches to cancer cells in her laboratory at ECU. DS-6 will serve as a delivery vehicle for a highly potent cell-killing agent developed by ImmunoGen specifically for delivery to cancer cells by antibodies. The antibody latches on to tumor cells and enables the whole compound – the antibody and the attached cell-killing agent – to enter the cancer cell. Once inside, the cell-killing agent becomes activated and kills the tumor cell as it divides.

‘We can’t give such a potent chemotherapy agent on its own because it would be too toxic, but if we can link it to an antibody, it goes inside the tumor cell and is released inside the tumor cell, which is really an amazing feat,’ Kellogg said.

The antibody with the cell-killing agent linked to it circulates in the body in an inactive state. The cell-killing agent becomes active only when it reaches the tumor cell, so ImmunoGen refers to its technology as Tumor-Activated Prodrug, or TAP, technology. Sanofi-aventis has rights to develop specific anticancer agents using ImmunoGen’s TAP technology and is in charge of advancing the TAP compound containing the DS-6 antibody licensed from ECU into human clinical testing.

Monoclonal antibodies are manufactured proteins, produced from a single parent cell, that bind to a specific substance. They can be used to detect or purify that substance and are widely used in hospital and pathology laboratories as components of diagnostic tests. Monoclonal antibodies gained attention as a possible way to treat cancer in the 1980s. In the 1990s, scientists refined techniques to expand their usefulness as therapeutics by making subtle changes to the antibodies so the human body would not reject them as foreign tissue. One of the best-known monoclonal antibodies is trastuzumab, sold under the brand name Herceptin and used to treat breast cancer.

Kellogg began working with monoclonal antibodies in the early 1990s looking for ones pathologists could use to diagnose cancer. A few years later, working with Dr. Diane Semer, a gynecologic oncologist formerly with ECU, Kellogg turned her attention to identifying an antibody that could not only recognize tumors but also be useful in treating them. She isolated DS-6 in the late 1990s and then began characterizing the antibody for its ability to recognize various types of cancer with the help of Dr. Nancy Smith, a former ECU pathologist.

‘Drugs that are developed from monoclonal antibodies are potentially more specific for tumors and risk less in the way of toxicity to the patient,’ said Dr. Adam Asch, associate director of the Leo W. Jenkins Cancer Center at ECU. Kellogg added that the treatment could have benefits even if it falls short of curing cancer. ‘You may be able to convert cancer to a very chronic disease you can treat if we can provide oncologists with a wider array of treatment options,’ she said.

‘This has been an amazing education for me and personally very rewarding to get a ringside seat in seeing the complex process of drug discovery and development take place. It has also demonstrated how well academia, biotechnology and pharmaceutical companies can work together in this process,’ Kellogg said.

Kellogg’s research has been funded in part by ECU and the Department of Pathology and Laboratory Medicine. ‘We feel we made a wise investment that will help advance the treatment of cancer by providing funds for Dr. Kellogg’s research,’ said Dr. Peter Kragel, chair of the department. Future grants from ImmunoGen and sanofi-aventis are under discussion.”

[Quoted Source: New Antibody Offers Hope for Treating Ovarian, Breast Cancer, NewsWise Medical News Release dated May 22, 2008.]