By Randall Osborne
West Coast Editor
Viventia Biotech Inc. isn¿t searching for the key to immortality ¿ the cancer research firm just wants to help patients live longer.
Toronto-based Viventia¿s strategy, though, does entail ¿immortalizing¿ B lymphocytes made by afflicted subjects¿ white blood cells, by way of making human-human hybridomas, or normal, antibody-making cells fused with cancer cells that keep them working.
¿We¿re nowhere near the autologous vaccine approach,¿ said Anthony Schincariol, president and CEO. ¿They¿re all individual to the patient. We have two human myeloma lines [we work with], and the cells are only individualized in the sense that they come from a breast cancer patient, or a colon cancer patient.¿
Having identified a promising hybridoma from those it has made, Viventia clones immunoglobulin genes from it and uses them to design a series of antibody molecules that can be tailored for various tasks. They are isolated, purified and injected into patients.
Viventia, with about 65 employees, was formed a year ago when Novopharm Ltd. was sold to Teva Pharmaceutical Industries Ltd., of Jerusalem.
¿The biotech portion was kept out by the primary shareholder, Leslie Dan, who is the second largest shareholder and a board member of Teva,¿ Schincariol said. Dan also is the primary shareholder of Viventia, with about 75 percent, and is chairman of the board.
¿What we see as our advantage is that the majority [of researchers] first identify and purify an antigen they feel is sufficiently expressed on the cancer cell, and then make an antibody,¿ Schincariol told BioWorld Today. ¿But we don¿t know the antigen when we go ahead. We don¿t know what¿s on that tumor cell, so we are able to identify molecules that bind to tumor cells against antigens that you may not be able to see on a purified structure ¿ on a plate ¿ but are present in vivo in a 3-dimensional structure of the tumor. Once you have a molecule you think is useful, you have to figure out what antigen it is binding to.¿
Viventia has two lead products.
H11 scFv, which is the IgM antibody H11 remade into a smaller molecule that seems to keep the tumor-targeting properties of the original, just completed a Phase I/II safety trial. It has potential for various metastatic cancers, including breast, ovarian and lung, Schincariol said.
¿Most of the dogma has been that you want the full molecule,¿ he said. ¿But, being smaller, [the single chain molecule] should penetrate tumors more fully, and it¿s cheaper to manufacture.¿
H11 scFv also shows promise as a tumor-imaging agent. It has allowed images within 30 minutes of injection in mice, while other such antibodies can take hours or days in humans.
Despite interest from clinicians, ¿we¿re not really concentrating on developing it as a diagnostic,¿ Schincariol said.
The other lead product is 4B5, a human IgG anti-idiotype antibody to the ganglioside GD2, a molecule that is present on a few normal tissues, but overexpressed on specific cancerous cells. It targets melanoma, small-cell carcinoma of the lung and neuroblastoma.
¿This is the vaccine approach,¿ he said. ¿It¿s also a small molecule, single chain, which we¿ve found to be more immunogenic than the full-sized molecule ¿ not an antibody against the antigen, but a mimic of the antigen on the tumor surface.¿
The rest of Viventia¿s pipeline is still being determined.
¿We¿ve got a heck of a lot of molecules, and we have to decide which are the best ones to move forward,¿ Schincariol said. ¿We have roughly 60 or 70, and we want to move one or two a year into the clinic.¿
Primary shareholder Dan continues to invest. Earlier this month, Viventia entered a financing arrangement with Dan Family Holdings Ltd., of Toronto, for up to C$6 million (US$3.91 million), to be attained by one of two investment options.
The first option consists of selling units, each of which consists of a share of stock and a purchase warrant, which let the holder buy another share. Each unit, like the exercise price of each warrant, is equal to the volume-weighted average trading price (VWAP) for the 10 days just before the second day before closing, or the weighted average trading price on those 10 days, whichever is greater.
Option two consists of a convertible debenture, bearing 8 percent annual interest, which may be converted into units that consist of one share and one purchase warrant, which lets the holder buy a share. Interest is payable semi-annually, in shares or cash, and the pricing is based on the 10-day VWAP or the weighted average trading price on the last day of the 10-day VWAP.
Viventia can require DFH to provide the funding if none has come from a third party before Aug. 31. After the company exercises its ¿put¿ right, the transaction is expected to close within 20 days, subject to regulatory approval.
Viventia reported a net loss of $11.6 million last year.
¿We have cash until this October in house,¿ Schincariol said. ¿But now we have backup commitments from Dan Family to carry us until next spring.¿
The company¿s unusual name was on a list suggested by the marketing firm that put together the company¿s annual report, Schincariol said.
¿They said, Give us $2,000 and we¿ll give you 10 names,¿¿ he said. ¿It has a nice ring, a sense of life. It doesn¿t mean anything, except the beginning comes from viva,¿ meaning life.¿
Staying robust will involve not only sifting the pipeline carefully, but also choosing the right partner at the right time, Schincariol said.
¿Our goal is to move products up to Phase II, and then begin to look at partnering options,¿ he said. ¿There¿s always that balance between going too early and going too late.¿ Informal talks already have been conducted with ¿all the people you might think of, plus some larger houses,¿ including South San Francisco-based Genentech Inc., he said.
¿We¿re in a mode to diversify financing, for a whole pile of reasons,¿ he added, declining to provide details. Meanwhile, Dan is ¿committed to continue funding, and he wants to get our products to Phase II,¿ Schincariol said. ¿That¿s the point where we¿ll move to the Nasdaq.¿
The company¿s shares (TSE:VBI) now trade on the Toronto Stock Exchange, where they closed Friday at 32 cents, down 3 cents.