Start-up Profiles

Published online: 22 February 2005, doi:10.1038/bioent845

Cellerant Therapeutics

*Ken Howard Wilan is a contributing writer based in Boston. kenhoward@mindspring.com

Targeting multiple diseases with a single stem cell type.

A dream team of scientific and business advisors will open many doors for a company. Cellerant Therapeutics has that all-star roster with a board that includes David Baltimore, president of Caltech in Pasadena, California, George B. Rathmann, cofounder of Amgen in Thousand Oaks, California, and Irving Weissman, director of the Stem Cell Institute at Stanford University School of Medicine in California, as well as Leroy Hood president of the Institute for Systems Biology in Seattle on the scientific advisory board. This star power no doubt helped attract $10 million in series A funding in 2003 for a company that has by some accounts a potential product high in risks and far from the market (see Cellerant profile).

		"Will cell-based therapeutics have the margin structure of the pharma industry? [Investors raised the] same questions about proteins and antibodies. Companies challenged that and made money."

Cellerant, based in Palo Alto, California, is developing treatments for immune disorders and genetic diseases based on research by Weissman and colleagues who in a 1992 paper identified and isolated hematopoietic stem cells¹. Eventually, the company also hopes to target cancer. The company's intellectual property was initially vetted at SyStemix, a company also founded by Weissman and eventually sold to Novartis AG of Basel, Switzerland, which has given Cellerant an exclusive license. Additional intellectual property has been licensed from Stanford University.

Cellerant's main product is highly purified stem cells from donor mobilized peripheral blood to be used in transplants for various immune diseases. The lure is to offer a one-time infusion of these new cells to not only cure a disease but also avoid graft-versus-host reactions that can occur with standard bone marrow transplants. Phase 1 clinical trials using this technology for patients with sickle cell anemia are scheduled to begin this year, says company president and CEO Bruce Cohen. He sees the approach also being applied to other immune disorders such as lupus, Crohn's disease, multiple sclerosis, rheumatoid arthritis and type 1 diabetes.

The company is also developing a manufactured myeloid progenitor (MP) cell product into high-risk, bone-marrow transplant patients as well as cancer patients to protect against opportunistic infection and neutropenia². It is hoped that the CMP product will produce a nonrenewing swarm of myeloid cells, including red blood cells, platelets and macrophages, once introduced into a patient. In late 2004 the company received a two-year $800,000 Small Business Innovation Research grant from the National Institute of Allergy and Infectious Disease to investigate the use of CMPs to rescue individuals exposed to lethal doses of radiation.

Cell morphology after 7 days expansion from single human hematopoietic stem cells showing mostly blast cells, with some clear myeloid cells, differentiated beyond the progenitor level.

Although the science seems persuasive in animal models, the true test, of course, will be in humans. And even if the data are positive, the process of introducing purified hematopoietic stem cells—which for every patient involves selecting an appropriate donor, removing cells from the donor, purifying the sample and introducing it into the patient who has had his or her own immune system destroyed—may be a relatively complicated and costly treatment.

This is "expensive technology—will a payor back these costs?" asks venture capitalist Brian Atwood with Versant Ventures of Menlo Park, California. "All these are unknowns for an investor with a lot of other opportunities to look at. With stem cells you have buckets and buckets of risk. It needs more time and money for commercialization."

"It is a difficult issue," agrees Cellerant CEO Cohen. "Will cell-based therapeutics have the margin structure of the pharma industry? [Investors raised the] same questions about proteins and antibodies. Companies challenged that and made money."

Cohen also said that his company is taking a different path from previously unsuccessful cell-based companies by using a single platform to target multiple disease indications. Still, Cohen acknowledges that although the company is now seeking $15 to $20 million in series B financing, some investors may try to reduce their risk by waiting for results from phase 1 trials.

References

1. Baum, C.M. et al. Isolation of a candidate human hematopoietic stem-cell population. Proc. Natl. Acad. Sci. USA 89, 2804–2808 (1992).

2. BitMansour, A. et al. Single infusion of myeloid progenitors reduces death from Aspergillus fumigatus following chemotherapy-induced neutropenia. Blood (2 December 2004) doi:10.1182/blood-2004-07-2676.