Two Abstracts Pertaining to the AE37 HER2/neu Vaccine Accepted as Poster Presentations at ASCO 2013

Two abstracts pertaining to Antigen Express' AE37 Her2/neu vaccine have been accepted for poster presentations at the 2013 American Society of Clinical Oncology ("ASCO") Annual Meeting. The annual ASCO meeting is being held in Chicago, Illinois from May 31 through June 4, 2013.

The abstract titles, with the name of the lead author, were revealed today with the launch of the meeting's iplanner. Here is the available information:

Abstract #3095

Booster inoculations of the AE37 peptide vaccine enhance immunological responses in a phase II study.

Eleftheria A. Anastasopoulou

Abstract #3097

Risk factors for development of delayed urticarial reactions in the phase II trial of HER2 peptide vaccines plus GM-CSF versus GM-CSF alone in high-risk breast cancer patients to prevent recurrence.

Alfred F. Trappey, MD

The iplanner is available for review here.

Emerging Vaccines Take Aim at Preventing Recurrent Breast Cancer

The following article was written by Joe Munch, and published in MD Anderson's OncoLog.

OncoLog, January 2013, Vol. 58, No. 1

Myriad advances have been made in the treatment of breast cancer, and cures are achieved in many patients. However, there are still patients whose cancer recurs, and most of these patients will die of their disease. This indicates a need for other therapies that can be used to prevent recurrent disease. One potential option is breast cancer vaccines.

“Breast tumors are made up of so many different types of cells that we have to use many different drugs and therapies to treat them,” said Jennifer Litton, M.D., an assistant professor in the Department of Breast Medical Oncology at The University of Texas MD Anderson Cancer Center. “Vaccines come at the cancer in a totally different way than our current systemic therapies do.” Vaccines thus may augment the effects of adjuvant treatments currently used to forestall recurrence.

Potential clinical role

Several types of adjuvant therapy are used to prevent breast cancer from returning; the therapy or combination of therapies used depends on the individual patients and their disease. For example, radiation therapy is used for patients who have undergone breast-conserving surgery, and chemotherapy may benefit patients at high risk of recurrence. Hormonal therapy with tamoxifen or an aromatase inhibitor is used in patients with estrogen receptor–positive disease, and immunotherapy with trastuzumab is used in those with tumors that highly express human epidermal growth factor receptor 2 (HER2).

Today, several clinical trials are evaluating the use of breast cancer vaccines—not as an alternative to currently available preventive therapies for recurrent disease but as an additional adjuvant therapy.

“This is a novel approach specifically for people who want another form of therapy to decrease the chance of the cancer coming back,” Dr. Litton said. “People are looking for something extra that may improve their outcome but doesn’t expose them to a lot of extra toxicity.”

Peptide vaccines

Cancer vaccines stimulate patients’ immune systems to recognize and kill tumor cells. The vaccines consist of a tumor-associated antigen that, once introduced into a patient’s body, elicits an immune response. Several systems have been devised to deliver tumor-associated antigens into the body, including whole-cell vaccines, viral vector vaccines, and dendritic cell vaccines, which are custom made from the patient’s own white blood cells. The only therapeutic cancer vaccine currently approved by the U.S. Food and Drug Administration is sipuleucel-T (Provenge), a dendritic cell vaccine used in men with metastatic hormone-refractory prostate cancer.

The breast cancer vaccines being investigated at MD Anderson are of a fourth type, peptide vaccines. Peptide vaccines are made by taking a small amino acid sequence (peptide) from a tumor-associated antigen. The tumor-associated antigen most frequently used in breast cancer vaccines is the HER2 oncoprotein, which promotes tumor growth.

Once taken from the antigen, the peptide is mixed with an immunoadjuvant to help stimulate an immune response. The immunoadjuvant used in the trials being conducted at MD Anderson is granulocyte-macrophage colony-stimulating factor (GM-CSF), which has been used primarily to treat neutropenia in transplant recipients.

When the peptide–GM-CSF combination is injected, GM-CSF stimulates the dendritic cells in the area of injection to take up and process the peptide so that it can be better presented to the immune system. The length of the peptide dictates the type of immune cell it stimulates.

Current clinical studies

Several HER2-derived peptide vaccines are being studied in clinical trials at MD Anderson. Although the vaccines are based on a HER2 peptide, they have the most benefit in the 60% of breast cancer patients with low HER2 expression (1+ or 2+ by immunohistochemistry).

Phase III trial of E75

The E75 vaccine (NeuVax) is the most studied of the HER2-derived peptide vaccines. The 9-amino-acid peptide E75 binds with major histocompatibility complex (MHC) class I molecules to stimulate CD8-positive T cells; when these T cells recognize a target as foreign, they attack it and release cytotoxic enzymes to kill it. Because E75 is an MHC class I peptide, the vaccine works only in patients whose cells are positive for human leukocyte antigen (HLA)-A2 or HLA-A3; only cells with those HLA types will present the peptide on the cell surface to activate T cells.

In May 2012, Elizabeth Mittendorf, M.D., Ph.D., an assistant professor in the Department of Surgical Oncology, and her colleagues published the 24-month landmark analysis of their phase I and II trials of E75. The group’s findings opened the door to the phase III PRESENT (Prevention of Recurrence in Early-Stage, Node-Positive Breast Cancer with Low to Intermediate HER2 Expression with NeuVax Treatment) study, currently the only phase III trial of a breast cancer vaccine. Dr. Mittendorf is the overall principal investigator of the multinational study.

This randomized, double-blind, placebo-controlled trial will enroll approximately 700 breast cancer patients who were rendered disease free following standard treatment. Patients must be positive for HLA-A2 or HLA-A3 and have had cancers that were scored as HER2 1+ or 2+ by immunohistochemistry. The vaccine will be given once a month for 6 months and then given as a booster inoculation every 6 months thereafter through 3 years. Because GM-CSF causes inflammation at the injection site, it will be given to patients in each study group, serving as the immunoadjuvant for the vaccine group and as an active placebo for the control group. The primary endpoint of the study is 3-year disease-free survival.

Positive results from this trial, researchers hope, would eventually lead to indications for the E75 vaccine in the routine care of breast cancer patients. “We are all cautiously optimistic—and excited—as we wait for the results. If they do show that E75 has significant benefit, it could be an amazing opportunity for our cancer patients,” Dr. Litton said.

Phase II trial of GP2 and AE37

The GP2 vaccine works in much the same way as the E75 vaccine. Like E75, the GP2 peptide is 9 amino acids long and binds to MHC class I molecules to stimulate CD8-positive T cells; thus, the vaccine works only in patients who are positive for HLA-A2 or HLA-A3. In contrast, the AE37 peptide, which is longer than the E75 and GP2 peptides, binds to MHC class II molecules and stimulates CD4-positive T cells, thereby eliciting a more robust immune response. Although MHC class II peptides can be HLA-restricted, AE37 is a promiscuous peptide, meaning that blood cells of almost any HLA type can present it. In addition, the AE37 peptide is paired with the Ii-Key protein, which enhances the presentation of the peptide to the immune system.

Both the GP2 and AE37 vaccines are being investigated in an ongoing phase II trial to determine whether the individual vaccines can prevent the recurrence of node-positive or high-risk node-negative breast cancer. Patients are sorted into groups depending on their HLA status and then randomly assigned to receive the appropriate vaccine plus GM-CSF or GM-CSF alone (as the control).

The AE37 trial’s planned interim analysis revealed that at a median of 22 months, the recurrence rate in the vaccinated patients was 10.3%, whereas the recurrence rate in the control group receiving only GM-CSF was 18.0%. The difference represents a 43% reduction in recurrence rate.

“These data are encouraging,” Dr. Mittendorf said. “Obviously, we need longer follow-up, and we need to finish accrual in the trial, but the data suggest that it is reasonable to look forward to investigating the AE37 vaccine in a phase III setting.”

The interim results for the GP2 vaccine are not yet available.

Potential benefits

One of the benefits of peptide vaccines such as those being investigated at MD Anderson is that they can be given “off the shelf.” This makes them more convenient and less expensive than the custom-made dendritic cell vaccines.

Dr. Litton, who has referred a number of patients to the breast cancer vaccine trials, said that patients’ enthusiasm about participating in a vaccine trial has been overwhelmingly positive. “Some patients tell me that they feel empowered by using their own bodies, their own immune systems, to fight the cancer,” she said.

But the main reason the trials are so popular with patients is that the vaccines offer a potential anticancer benefit with very little risk of toxicity. Most patients have a grade 1 or 2 local toxic response, which means redness at the injection site; and some patients experience grade 1 or 2 systemic symptoms, mostly in the form of minor flu-like symptoms for 4–6 hours after receiving the vaccine.

“These are people who have gone through chemotherapy, lost their hair, and had terrible gastrointestinal side effects, toxicity in their nails, and all those other things,” Dr. Mittendorf said. “So a treatment that is basically not toxic is very attractive.”

Dr. Litton echoed Dr. Mittendorf’s sentiments. “It has not been a hard trial for people to become interested in. In fact, I’ve had several people come from different parts of the country just to be part of the trial,” Dr. Litton said. “And we really appreciate all the patients who have stepped forward to participate. It’s always important to encourage people to participate in clinical trials; otherwise we could never move forward with therapies such as this.”

These vaccines are not for everyone, however. Earlier clinical trials revealed that the peptide vaccines had limited efficacy in patients with late-stage, metastatic breast cancer.

“There’s a long list of reasons why these vaccines are not set up to be administered to patients who have diffusely metastatic disease,” Dr. Mittendorf said. “It would be difficult, with a peptide vaccine, to mount enough of an immune response to eradicate bulky disease. The microenvironment and immune environment around tumors change as tumors progress, so bulky metastatic tumors also have a less favorable environment for the immune system to function in. And a lot of patients with diffusely metastatic disease have received multiple lines of chemotherapy, which we suspect has a detrimental effect on the immune system.”

Future directions

The future of breast cancer vaccines holds many possibilities. Antigens such as cyclin E and folate-binding protein may be targeted for vaccination. Novel immunoadjuvants are being developed that may elicit an immune response more potent than that elicited by GM-CSF. And new approaches using vaccines and harnessing other aspects of the body’s immune system against recurrent breast cancer may be forthcoming.

“I would like to see some of these vaccines combined with other exciting immunotherapies that are coming on board,” Dr. Mittendorf said. For instance, a vaccine could be paired with a drug that inhibits CTLA-4, a protein that downregulates T cells. “Ipilimumab, an antibody that targets CTLA-4, could be used to take the brakes off the immune system. A vaccine would stimulate the T cells, and the anti–CTLA-4 treatment would allow them to proliferate,” she said.

Eventually, such vaccines could be used to treat patients much earlier in the course of their disease. “I think it would be an exciting route to look forward to in the frontline setting as well,” Dr. Litton said. “We could potentially cure more people up front at the time of diagnosis.”

Please click HERE to view this article at OncoLog.

Reasearchers from MD Anderson Present Interim Phase II Date for AE37 at ASCO's 2012 Breast Cancer Symposium

Early Efficacy Analysis of the AE37 Vaccine in Patients with HER2 Low-Expressing and Triple-Negative Breast Cancer.

Abstract No:
109

Author(s):
Elizabeth Ann Mittendorf, Sonia A. Perez, Diane F. Hale, Timothy J. Vreeland, Alan K. Sears, Guy T. Clifton, Alexandros Ardavanis, Nathan M. Shumway, James L. Murray, Sathibalan Ponniah, Michael Papamichail, George Earl Peoples

Abstract:

Background: Peptide vaccines comprised of HLA class II epitopes, which elicit CD4+ T cell responses, play a critical role in potentiating immune responses. We are conducting a randomized phase II trial of AE37, a hybrid peptide created by the addition of the Ii-Key moiety (LRMK) to the HER2 helper epitope, AE36 (HER2 aa776-790). Here, we present efficacy data focusing on outcomes in patients with low HER2 (IHC 1+ or 2+) expression and triple negative breast cancer (TNBC).

Methods: The trial is enrolling node positive or high risk node negative breast cancer patients with any degree of HER2 expression (IHC 1+, 2+ or 3+ or FISH > 1.2) rendered disease-free following standard of care therapy. Patients are randomized to receive either AE37+GM-CSF or GM-CSF alone in 6 monthly intradermal inoculations followed by booster inoculations administered every 6 months.

Results: The trial has enrolled 254 patients; 105 in the vaccine group (VG) and 149 in the control group (CG). After a median follow-up of 22.3 months, the disease-free survival (DFS) rate in the VG is 90.3% vs 81.1% in the CG (p=.46), a 49% risk reduction. Evaluating patients with low HER2 expression (IHC 1+ or 2+), there are 53 VG patients and 77 CG patients. The groups are well-matched with respect to the percentage of patients with high grade tumors, tumors > 2cm, the rate of node positivity and ER/PR status (all p>.5).

The DFS rate in the VG of low HER2 expressers is 89.8% vs 68.2% in the CG (p=.12), a 68% risk reduction.

When limiting analyses to patients with TNBC (ER/PR negative, HER2 1+ or 2+), there are 13 VG patients and 23 CG patients. The groups are again well-matched with the exception of control patients having a larger percentage of tumors > 2 cm (70% vs 31%; p=.02).

The DFS rate in the VG of TNBC patients is 83.3% vs 47.6% in the CG (p=.23), a 68% risk reduction.

Conclusions: Early analyses suggest clinical benefit to vaccination with AE37, particularly in patients with low HER2-expressing tumors. Importantly, the benefit appears to persist in TNBC patients. Patients will continue to be followed per protocol for 5 years; however, these data suggest that a subsequent phase III trial should evaluate the vaccine in patients with low HER2-expressing disease to include TNBC.

Here is a link to the abstract.

Let's get wonky! Generex Pipeline Review's unexpert discussion:

The most differential aspect between the results Dr Mittendorf et all present at this week's ASCO Breast Cancer Symposium vs. the ASCO Annual Meeting from June is the inclusion of disease free survival rates for triple negative cancer subjects. Triple negative patients test negative for estrogen receptors (ER-), progesterone receptors (PR-), and HER2 (HER2-). According to breastcancer.org,

These negative results mean that the growth of the cancer is not supported by the hormones estrogen and progesterone, nor by the presence of too many HER2 receptors. Therefore, triple-negative breast cancer does not respond to hormonal therapy (such as tamoxifen or aromatase inhibitors) or therapies that target HER2 receptors, such as Herceptin (chemical name: trastuzumab). However, other medicines can be used to treat triple-negative breast cancer.

About 10-20% of breast cancers — more than one out of every 10 — are found to be triple-negative. For doctors and researchers, there is intense interest in finding new medications that can treat this kind of breast cancer. Early studies are trying to find out whether certain medications can interfere with the processes that cause triple-negative breast cancer to grow.

In the new AE37 study, a much higher percentage (70%) of triple negative subjects within the control group have a tumor size greater that 2 cm, while 69% of triple negative subjects in the vaccine group have a tumor size less than 2 cm. Share cancersupport.org informs that-

triple negative breast cancer tumors are also classified into four stages on the basis of size and lymph-node involvement. Stage I means that the tumor is less than 2 cm in size and there is no lymph node involvement. Stages II and III indicate larger size and degrees of lymph node involvement. Stage IV means that metastasis has already occurred.

With this in mind, it appears that the majority of triple negative subjects in the control group have Stage II tumors, while the majority of triple negative subjects in the vaccine group have Stage I tumors. The difference is noted by the authors of the abstract as being statistically significant, p=.02. For an optimum comparison, the groupings in a planned Phase III study will need to more evenly matched.

However, all of that aside, the results for triple negative subjects within the AE37 arm of the study are quite promising. These subjects have a disease free survival rate of 83.3% at 23.3 months, and the first 24 months appear to be the most critical.

The Oncologist's 2012 article titled Triple-Negative Breast Cancer: An Unmet Medical Need states that "fundamentally, in the early-stage setting, triple-negative breast cancer is associated with earlier versus later events, as well as a shorter period from the time of recurrence until death." They inform in their conclusion remarks that-

triple-negative breast cancer is clearly a distinct subtype, from the perspective of both ER and HER-2, and there may yet be further distinct subclassifications. This disease presentation clearly represents an important clinical challenge. Triple-negative breast cancer is also a surrogate of basal-like breast cancer. Therefore, trials designed to accrue patients with basal-like breast cancer using ER/PR and HER-2 negativity provide an approximation of the triple-negative population, but, as described in the introduction, there is some discordance, including some HER-2 positives and some ER positives among the basals. At present, there is not a clear, proven effective single agent that targets a driving vulnerability in triple-negative breast cancer. However, there are a number of potential therapies currently under investigation that may eventually improve outcomes in these patients.

WebMD estimates that between 10 - 17% of cancers are triple negative. Previous reports estimated that approximately 80% of breast cancer patients could be treated with AE37 if the vaccine gains approval by the FDA. In this estimate, they appeared to be noting subjects that are low and high expressors of HER2/neu. We now see the researchers adding triple negative subjects to their Phase III plannings, and this certainly is a positive development for Generex and Antigen Express.

Currently, Generex's shareholders are waiting to hear an update on the long planned spin out of Antigen Express. Such an update is long overdue, and until then any plans for a Phase III appear to be in a state of limbo. Hopefully, the continued positive results for AE37 bring Generex much needed momentum in their spinout plans for Antigen Express.

One other quick note- during the ASCO Annual Meeting held in June, the researchers noted that they "have enrolled 201 patients to our phase II trial (Vaccine (VG)=103, Control (CG)=98)." This new abstract notes that they have "enrolled 254 patients; 105 in the vaccine group (VG) and 149 in the control group (CG)." The new abstract shows results at 23.3 months, and the June abstract shows results at 22 months. In this update, only 4 subjects have been added to the AE37 arm, while 51 have been added to the control group. Overall, this is the largest controlled study for a peptide based vaccine to treat breast cancer in the adjuvant setting.

As Generex's stock continues to decline, their AE37 breast cancer vaccine continues to shine. At some point, AE37 should have a long lasting positive effect on shares of GNBT, while the more important goal is to cure early stage breast cancer.

ABC News Features a Report on the AE37 HER2 Cancer Vaccine

Click the word VIDEO to see the ABC news segment.

Two Late Breaking Abstracts Featuring Antigen Express' AE37 Peptide Vaccine for HER2/Neu Breast Cancer Patients to be Presented at AACR 2012

The AACR Annual Meeting will highlight the best and latest findings in all major areas of cancer research. Cancer researchers continue to make incredible strides and breakthroughs, with an impact on global health. The theme of the AACR Annual Meeting 2012, “Accelerating Science: Concept to Clinic,” reflects this amazing progress and emphasizes the synergy between basic, clinical and translational research that will continue to lead to effective cancer therapies and prevention strategies. The meeting takes place March 31-April 4 in Chicago.

Two late breaking abstracts featuring Antigen Express' AE37 Peptide Vaccine for HER2/Neu breast cancer patients will be presented at the AACR Annual Meeting. The titles of the abstracts, and names of the authors, have been made available at the meetings website:

Late-Breaking Poster Session
LBPO.IM01. Late-Breaking Research: Immunology
Mon, Apr 2, 1:00 - 5:00 PM
Abstract Number:
LB-130

Presentation Title:
Immune reconstitution after chemotherapy correlates with increased in vitro immune response in breast cancer patients undergoing peptide vaccine therapy

Location:
McCormick Place West (Hall F), Poster Section 40

Author Block:
Timothy J. Vreeland, Raetasha S. Dabney, Diane F. Hale, Alan K. Sears, Guy T. Clifton, Athina Zacharia, Yusuf Jama, Anna Chiplis, Mohamed Mursal, Nathan M. Shumway, Ritesh Patil, Jarrod P. Holmes, Elizabeth A. Mittendorf, George E. Peoples, Sathibalan Ponniah. San Antonio Military Medical Center, San Antonio, TX, Cancer Vaccine Development Lab, USUHS, Bathesda, MD, Roswell Park Cancer Institute, Buffalo, NY, Redwood Regional Medical Group, Santa Rosa, CA, UTMD Anderson, Houston, TX

Late-Breaking Poster Session
LBPO.CL01. Late-Breaking Research: Clinical Trials
Tue, Apr 3, 8:00 AM - 12:00 PM
Abstract Number:
LB-218

Presentation Title:
Immune response assessment in a phase II trial of AE37 HER2 peptide vaccine

Location:
McCormick Place West (Hall F), Poster Section 40

Author Block:
Diane F. Hale, Timothy J. Vreeland, Raetasha S. Dabney, G Travis Clifton, Alan K. Sears, Efi Pappou, Eleftheria Anastasopoulou, Alexandros Ardavanis, Sathibalan Ponniah, Michael Papamichail, Sonia Perez, Nathan Shumway, George E. Peoples, Elizabeth Mittendorf. Brooke Army Medical Center, Ft. Sam Houston, TX, St. Savas Cancer Hospital, Athens, Greece, Athens, Greece, Cancer Vaccine Development Lab, U.S. Military Cancer Institute, Uniformed Services University of the Health Sciences, Bethesda, MD, University of Texas MD Anderson Cancer Center, Houston, TX


The AACR 2012 website can be found by clicking here.

Antigen Express' AE37 HER2 Peptide Vaccine Named to Shortlist for 5th Annual ViE Awards

Antigen Express' lead vaccine, the AE37 HER2/neu synthetic peptide vaccine, has has been named as a nominee for the BEST THERAPEUTIC VACCINE (approved or in development) according to the shortlist published today for the 5th Annual Vaccine Industry Excellence (ViE) Awards. The ViE awards, sponsored by Novartis Vaccines and Diagnostics, were created to recognize the accomplishments and contributions of companies and individuals in the vaccine industry over the previous 12 months.

The full list of nominees in the Best Therapeutic Vaccine category are:

•Advaxis: ADXS-HPV - HPV

•Antigen Express: AE37 - Breast cancer

•BioSante Pharmaceuticals: GVAX

•Galena Biopharma: NeuVax - Breast cancer

•ImmusanT: Nexvax2 - Celiac disease

•Inovio Pharmaceuticals: VGX-3100 - Cervical cancer

The ViE Award nominees are voted on by those in the global vaccine industry and also judged by a panel of representatives from pharma, biotech, academia, government, non-governmental organizations (NGOs), and public health. Winners are announced at the annual ViE Awards dinner and ceremony, taking place this year on April 11 during the World Vaccine Congress in Washington, D.C. Click on AE37 Vaccine to go to the ViE Awards link on the World Vaccine Congress' website.

Bring it home, Antigen Express!

Antigen Express Makes Progress in Targeting Early Stage Breast Cancer Patients Who Don't Benefit From Roche's Herceptin

As we look forward to cancer research developments in 2012, let's first take a quick look back to 2005. In that year, Genentech, which was acquired for $46.8B in 2009 by Roche (RHHBY.PK), presented findings for their now blockbuster cancer fighting drug Herceptin to a packed room at ASCO's Annual Meeting. Herceptin was found to reduce the risk of recurrence 46% in women with early stage over expressing HER2 breast cancer, according to results reported for the first time from the large scale international HERA study.

Results from HERA showed that Herceptin significantly improved disease free survival at two years, from 77.4% in the observation group to 85.8%. Lisa Hutchinson, the Editor of Nature ReviewsClinical Oncology, wrote at the time that the Herceptin report "received rapturous applause and a standing ovation" from physicians and other attendees at the ASCO session.

Herceptin is a humanized monoclonal antibody that binds to a specific epitope of the HER2 protein on the breast cancer cell surface. Herceptin is a HER2+ breast cancer therapy designed to treat aggressive HER positive metastatic and adjuvant breast cancer. Adjuvant therapy is used after primary treatments, such as surgery or radiation for early stage invasive breast cancer. This additional treatment may reduce the risk that cancer will return.

The IHC test gives a score of 0 to 3+ that indicates the amount of HER2 receptor protein in tumors. Women with IHC positive scores tend to respond favorably to Herceptin. Samples with strong HER2 overexpression, IHC 3+, indicate eligibility for Herceptin therapy. This population makes up approximately 25% of HER2/neu breast cancer patients.

In the first six months of 2011, Roche reported worldwide sales of Herceptin at $3.5B. Approximately 70% of Herceptin's global sales come from adjuvant therapy for women with early-stage HER2 breast cancer following surgery. Immunological agents in development that target patients that exhibit lower expression of the HER-2/neu protein can fill an unmet medical need, and potentially earn far greater sales than Herceptin if they move on to win FDA approval.

During December's San Antonio Breast Cancer Symposium, cancer immunotherapy took another significant step in that direction when interim Phase II results were revealed for Antigen Express' AE37 HER2/neu peptide breast cancer vaccine. Antigen Express is a wholly owned subsidiary for Generex (GNBT.OB) Biotechnology. Here are highlights from the SABCS presentation:

+ Disease-free survival in the low HER2 expressing patients, or the larger percentage of breast cancer patients who are not eligible for Herceptin, was 88.6% in the treated group, n=53, versus 71.9% in the control arm, n=78, at a median follow-up of 22 months.

+ The AE37 vaccine elicits statistically significant peptide specific in-vivo and ex-vivo immune responses, which are maintained for 12 months after completion ofthe vaccine series, while there have been no proliferative changes for control patients.

+ Vaccine patients had statistically significant increases in DTH reactions, while controls had no response.

+ 99% of local and systemic toxicities were grade 2 or less. There have been no grade 4-5 local or systemic toxicities.

+ AE37 represents the only HER2-based peptide vaccine currently being studied in a randomized trial, and its use is not restricted to patients with a particular type of HLA peptide.

There are currently over 250 patients enrolled in the well designed Phase 2 study, the largest breast cancer adjuvant vaccine trial conducted to date. As a result of these findings, Antigen Express announced that they are "assessing the data for potential opportunity to move forward with a Phase 3 clinical development program following an End-of-Phase 2 meeting with the FDA for AE37, which Antigen Express believes, if confirmed, could occur in the first half of 2012". The company will seek a special protocol assessment SPA approval from the FDA. The current ongoing, controlled, randomized, and single-blinded Phase 2 clinical study will continue as planned to enroll a total of 300 women. Further Phase II results, providing a catalyst moment for GNBT's stock, are due within 2012.

Antigen Express is seeking a large Pharma partner to help fund the pivotal Phase 3 clinical development program in women with breast cancer that express low to moderate levels of HER2. A randomized, controlled, double blind study in 1000 HER 1+ 2+ node positive and high risk node negative patients across the US, Europe and Asia is projected to start later in 2012, once a large Pharma partner is in place.

The AE37 cancer vaccine has also been studied in a completed Phase 1 trial with prostate cancer patients demonstrating appropriate dosing and immune activation similar to that seen in the breast cancer trials. Antigen Express is gearing up to move AE37 more rapidly into larger Phase II clinical trial in men with newly diagnosed HER2 positive prostate cancer, which are currently being designed with leading oncologists in prostate cancer. HER-2/neu is over expressed in 11% of ovarian cancers, 39% of prostate cancers, 7 – 34% of gastric cancers, 10 – 82% of pancreatic adenocarcinomas, and is expressed at some level in the majority of epithelial-derived cancers. The potential market for a HER2-based peptide vaccine, such as AE37, is much larger than women with early stage breast cancer or men with newly diagnosed HER2 positive prostate cancer.

Beyond these known developments, a November 2011 patent application reveals plans to further research into combination therapy of AE37 with Herceptin by the Henry M. Jackson Foundation for the Advancement of Military Medicine. The patent details a Phase I study protocol that currently includes 102 disease-free breast cancer patients that over express HER2, IHC 3+, further expanding AE37's potential market grasp. In the patent, the researchers of the study, who are independent of Generex and Antigen Express, state in regards to the study's outcomes that "the in vivo DTH data strongly suggest that AE37 in combination with Herceptin should be more effective at reducing breast cancer recurrence and increasing disease-free survival time than Herceptin alone".

Investing in small biotechs comes with great risk, and each investor is responsible to themsleves to conduct their own due diligence. Generex had previously outlined plans to conduct a reverse stock split of GNBT shares sometime in the near future, only in conjunction with a move to a major exchange, to spin out Antigen Express, while retaining controlling interest, and the spin-out will be accomplished by the issuance of one or more dividends of Antigen Express stock to Generex stockholders. The company has not publicly altered these intentions, and shareholders are awaiting an update on these key areas.

What we may be witnessing is a new era in therapeutic cancer vaccines where the earlier setbacks seen in the overall industry make way to success stories, as Herceptin's success has done for the monoclonal antibody market, as I wrote to an industry leader last year. "I do believe that the cancer vaccine market will follow after the monoclonal antibody market. Once there is a clear cut success story, then all the big pharmas will race to secure their own cancer vaccines to bring to market," expressed Col George E Peoples MD, FACS, Director, Cancer Vaccine Development Program, in a response email. I am increasingly hopeful that Antigen Express' AE37 will prove to be the revoltuionary vaccine that leads the way.

The Journal of Immunology to Publish Study Detailing Generex Biotechnology's Research Collaboration with the Mayo Clinic in July Edition

The July edition of the Journal of Immunology, a peer-reviewed research publication of the American Association of Immunologists, features an article that will detail the research collaboration between Generex's (GNBT) wholly owned subsidiary, Antigen Express, and the Mayo Clinic. The research is a continuation of scientific study between Antigen Express, lead by President Dr. Eric von Hofe, and the Mayo Clinic's Dr. Keith Knutson, a leader in the field of peptide vaccines in breast cancer. The title of the future article is "MHC Class II Epitope Nesting Modulates Dendritic Cell Function and Improves Generation of Antigen-Specific CD4 Helper T Cells". The abstract and article are not yet available for view, but the title is included in the Journal's future table of contents.

Antigen Express has been developing a series of CD4+ T Cell helper epitopes, based upon their proprietary Ii-Key hybrid technology. Ii-Key is a portion of the MHC class II associated invariant chain, which is known as Ii. Antigen Express explains that Ii-Key facilitates the direct loading of epitopes to the MHC class II molecule groove. Utilizing their technology, Antigen Express' Ii-Key/MHC class II epitope hybrids have shown clinical evidence of greatly enhancing the vaccine potency of the tethered epitope. Antigen Express' most advanced vaccine is AE37, a HER-2/neu hybrid peptide which is currently in a multi-center Phase II study.

The Mayo Clinic's Dr. Knutson has long studied adoptive T Cell therapy strategies to create cancer vaccines designed for immunotherapy of HER-2/neu breast cancer. Adoptive T Cell therapy strategies have largely focused generation of CD8+ T Cells, due to observations that most tumours express MHC class I, but not MHC class II. This gets tricky, so here is some info on CD4+ T Cells vs CD8+ T Cells. CD4+ T Cells recognize antigen-derived peptides in the context of self-MHC class II molecules, while CD8+ T Cells recognize antigen derived peptides in the context of self MHC class I molecules.

The problem Dr. Knutson had previously encountered is that CD8+ T-cells have a short lifespan. Earlier, Dr. Knutson reported that a problem with the use of adoptive T Cell therapy included the lack of CD4+ T cell help. In further work, Dr. Knutson has found that patients immunised with with CD4+ HER-2/neu helper epitopes, such as being developed by Antigen Express, are able to develop long lasting HER-2/neu specific CD8+ T Cell immunity. Specifically, Dr. Knutson found that greater than 60% of patients immunised with CD4+ HER-2/neu helper epitopes, each containing an encompassed HLA-A2 epitope, were able to develop HER-2/neu specific CD8+ T-cell immunity. The CD8+ T Cell response was maintained, in some patients, for at least one year following vaccination.

In contrast, 40% patients immunised with a single CD8+ T Cell HER-2/neu HLA-A2 9-merpeptide, RXI Pharmaceuticals' (RXII) NeuVax, or E75, developed HER-2/neu CD8 T Cell immunity that declined to undetectable levels within 5 months of the last vaccination. AE37 is the HER-2/neu CD4+ T Cell helper containing an encompassed HLA-A2 epitope that outshines E75 given alone in his study. If a main problem for Dr. Knuston's adoptive transfer research had been the lack of CD4+ T cell help, Dr. von Hofe and Antigen Express presented the solution.

Since we know the title of the upcoming research article authored by Dr. Knutson and Dr. von Hofe, with other Mayo Clinic researchers, is "MHC Class II Epitope Nesting Modulates Dendritic Cell Function and Improves Generation of Antigen-Specific CD4 Helper T Cells", we have a clue on where they are going with this research. A 2010 patent by Dr. Knutson, titled "METHODS AND MATERIALS FOR GENERATING T CELLS", explains what is invloved in generating antigen-specific CD4+ T cells. The patent outlines methods and materials for using nested MHC class II epitopes to generate CD4+ T cells. The patent states that the nested MHC class II epitopes provided can include an invariant chain, or Ii, and a MHC class II epitope. The patent is describing his work with Antigen Express, and the upcoming article will provide peer review documentation.

Antigen Express is also involved in a separate collaboration with the Mayo Clinic's Dr. Svetomir Markovic, a distinguished translational researcher with expertise in melanoma trials. That agreement focuses on advancing an immunotherapeutic vaccine for melanoma into the clinic. Generex is planning a spin out of Antigen Express, following approval of a reverse stock split of Generex's shares. Top industry scientists, like those found at the prestigious Mayo Clinic, are already excited about the potential found within Antigen Express' pipeline. I am certainly no scientist, so read my opinions and rough analysis with that in mind, but the potential for Antigen Express is obviously high.

Should Generex's planned reverse stock split proposal be approved, followed by a spin out of Antigen Express, adequate funding may finally be within Antigen Express' grasp, which will serve as the fuel to propel all of this successful research deeper into human studies. The winners in that scenario will be Generex's current and Antigen Express' future shareholders, and most importantly the cancer patients in need of better therapy. We are looking at the future when active immunotherapy will be a commercialized reality, designed by Antigen Express.