Calimmune, Inc. today announced that encouraging results from a first group of participants indicates the company is ready to begin treating a second cohort in a clinical trial involving the use of Cal-1, an innovative gene-based stem cell therapy to help protect individuals infected with HIV from progressing to AIDS.

“While still early in clinical development, this announcement demonstrates real progress towards this mission. The accomplishment of Calimmune’s team is a great example of how CIRM partnerships are working to impact patient’s lives today.”

Calimmune was given approval to move ahead following a review of safety data by their Data Safety Monitoring Board (DSMB). The DSMB confirmed that none of the participants experienced any serious adverse events or dangerous side effects from the therapy.

“We are very excited and encouraged by this development,” says Louis Breton, Chief Executive Officer of Calimmune. “This recommendation from the DSMB is an important step in bringing this potential one-time therapy to the patients, and takes us closer to our ultimate goal of eradicating AIDS.”

Breton continued: “We are proud of our ongoing partnership with the California Institute for Regenerative Medicine (CIRM), and are most appreciative of their continued financial support of this critical effort.”

The Phase I/II clinical trial focuses on a protein called CCR5 that plays a critical role in enabling HIV to infect cells. Blocking CCR5 expression may provide the cells a protective shield against HIV, which in turn would help retain immune system functionality.

“The mission of CIRM is to efficiently accelerate the development of stem cell treatments for patients suffering from unmet medical conditions,” said, C. Randal Mills, Ph.D., President and CEO of CIRM. “While still early in clinical development, this announcement demonstrates real progress towards this mission. The accomplishment of Calimmune’s team is a great example of how CIRM partnerships are working to impact patient’s lives today.”

In the first phase of this study 4 HIV-positive participants were infused with their own blood stem cells as well as mature T cells that had been modified to carry a gene that blocks production of CCR5. The hope is that those stem cells will then create a new blood system that is resistant to HIV. To guard against the virus forming resistance, the team has used a second mechanism to prevent the virus from fusing with the patient’s cells.

The participants had all previously been on anti-retroviral drugs but had discontinued taking them because of side effects or treatment fatigue.

The second group of 3-4 participants will not only get Cal-1 but will also get a preconditioning regimen with the aim of making the therapy more effective.

The goal of the trial – which is being conducted in San Francisco and Los Angeles – is to assess the safety of the therapy, to determine the ease of use and feasibility of the approach for HIV/AIDS patients and to evaluate what, if any, side effects there may be.

“With more than one million Americans living with HIV, there is clearly an urgent need for a therapy that does more than just hold the virus at bay,” says Jonathan Thomas, Ph.D., J.D., Chair of the stem cell agency’s governing Board. “Current medications are effective, but come with a big cost both in terms of dollars and side effects. Our goal is to find an approach that effectively cures people with HIV/AIDS.”