HerpV

HerpVは、アメリカにあるAGENUSという会社で開発されている（まだ開発中）ワクチンで、現在Phase Iを完了したとのことです。

HerpVは、所謂「熱処理により弱毒化されたHSVワクチン」なのですが、以下の記事にも書いてあるように、「特にHSV-2ウイルスに対抗する2種類のT細胞（CD8+とCD4+）を活性化させる」ことに大きな特徴があるようです。

AGENUS HPより
http://www.agenusbio.com/herpv/herpv.html


There is a strong scientific rationale for developing a herpes vaccine that is focused on T cell generation, like HerpV. Evidence has accumulated that CD8+ and CD4+ T cells localize to herpes skin lesions in humans and persist for many weeks after lesion healing; also, persistence of HSV-specific CD8+ T cells in neurons is associated with maintenance of viral latency.

Further, it has been observed that robust CD4+ and CD8+ T cell activity against HSV-2 antigens can be detected in individuals who have clearly been exposed to HSV-2, yet remain HSV-2 seronegative and asymptomatic.

Despite this evidence, many vaccine approaches to HSV-2 have focused on induction of antibody responses. Further, such efforts have included only a small number of HSV-2 antigens. Attempts to induce broader immune response (antibody and cellular) using attenuated or replication incompetent viruses have not been successful and carry potential safety or manufacturing concerns.

In contrast, HerpV is a highly multivalent synthetic vaccine that has been shown to induce CD4+ and CD8+ T cell responses. The broad spectrum of herpes antigens in HerpV is intended to allow for more accurate immune targeting and surveillance, reducing the likelihood of immune escape. Further, the diversity of antigens in HerpV increases the chance of providing protection for a wide segment of the patient population.

現在のところ、Phase Iの結果を論文として掲載するための準備を進めており、少なくとも今年の末には研究論文として出版できる見込みのようです。

気になるその結果についてですが…、先日（2011年7月末）に行われた株主対象説明会を見てみると…、

1. CD4+ T細胞の増加　・・・　投与した内の100％（8/8人）　〇
2. CD8+ T細胞の増加　・・・　投与した内の75％  （6/8人）　〇
3. CD4+ および CD8+ T細胞の両方を増加させることができたワクチンは、このHerpVがはじめて！

ということのようです。

CD4+ と CD8+ T細胞がどのようにHSV-2ウイルスに作用するかは分かりませんが、最低でも「活性化した時点でT細胞が捕食する」ことになると思うので、ウイルスのOutbreakをかなりの程度抑えることができるのではないでしょうか…。


AGENUS 株主説明会

Transcriptはhttps://sites.google.com/site/herpescureresearch/herpes-vaccine/herpv---agenusより転載…

Lastly, I will discuss HerpV, our recombinant series therapeutic vaccine candidate for the treatment of genital herpes. During the quarter, David Koelle, a highly regarded doctor in the infectious diseases field, specifically herpes and a professor of medicine in the Division of Allergy and Infectious Diseases at the University of Washington School of Medicine, which is one of the leading centers of these types of diseases in the world, presented Phase 1 data at the BIO International Convention in Washington.

A manuscript on the full data set has been submitted to peer-reviewed journal. According to the centers for disease control, genital herpes affects more than 60 million Americans.

Our Phase 1 trial showed that 100% of the valuable patients receiving HerpV with QS-21 demonstrated a statistically significant CD4+ T cell response to HSV-2 antigens. In addition, 75% of these patients also demonstrated a CD8+ T cell response. I would like to note that list of both of these types of immune responses is the first of its kind achievement in herpes therapy.

(Inaudible) is the first to demonstrate that each had 14 complex survival antigens when used in antigen-specific T-cell response in humans.

Recent advances in therapeutic vaccines and immune-based products have helped validate that harnessing the power of the immune system could have far-reaching implications for diseases that have been historically very difficult to treat such as genital herpes.

Our company is currently defining a Phase 2 development program for HerpV, which is anticipated to include measuring a reduction of viral shivering in patients which is expected or which is regarded rather as a very important surrogate for clinical outcomes.


HerpV自体の結果は非常にいいと思うのですが、この企業、経営が多少苦しいらしく、Phase IIを実施できるのかどうか…、微妙なところかもしれません。事実、Phase Iを完了するのにも結構年数がかかってしまったようで、その背景にはどうやらこの経営問題があるかもしれないですね…。

上記の株主説明会の続きを聞いてみたら、「できれば2012年の2月から行いたいと考えている」みたいなことを述べておられましたが、これも「パートナー次第」ということになるかもしれません…。

ただ、この説明会では、「HerpVの開発は積極的に行っていきたい」という旨の発言もあったので、期待できる面も十分あるかと思います。

Phase Iの結果は良いと思うので、是非、Phase IIに進んで欲しいと思います！