BioWorld Today Contributing Writer

Shares in RXi Pharmaceuticals Corp. (NASDAQ:RXII) jumped 14 percent Monday on news that the FDA had cleared a chemistry, manufacturing and controls (CMC) partial clinical hold on its lead cancer vaccine, NeuVax. Now that the Worcester, Mass.-based company has satisfied all of the FDA's requirements, it is on schedule to begin its Phase III (PRESENT) trial in early 2012.

"We're looking to be the first vaccine in breast cancer in Phase III clinical trials early next year," Mark Ahn, President and CEO of RXi, told BioWorld Today.

Prior Phase II trial results have been positive, and RXi is evaluating NeuVax under a special protocol assessment for HER2 positive breast cancer – a market in which Herceptin rang up $5 billion in sales in 2010.

NeuVax is a combination of E75 peptide from HER2 and immune adjuvant granulocyte macrophage colony-stimulating factor (GM-CSF), designed to stimulate cytotoxic (CD8+) T cells to target cells expressing HER2 at any level.

The T cells expand and proliferate, and as they circulate through the body, they identify and destroy HER2 positive cancer cells.

Two-thirds of patients diagnosed with HER-positive breast cancer are ineligible for Herceptin because their genetic test results show they have low to intermediate HER2 expression or less than 2 million copies of the HER2 receptor per cell.

NeuVax is an off-the-shelf product given as an intradermal once-a-month injection for six months, with a subsequent booster every six months. It is being developed as an adjuvant therapy, given after standard care for HER2/neu positive breast and prostate cancer patients.

NeuVax was developed by Apthera Inc., based in Scottsdale, Ariz. RXi acquired Apthera in April, beefing up its late-stage pipeline in the process. (See BioWorld Today, April 1, 2011.)

The optimal dose and schedule of NeuVax was established in 2008 as 1-mg E75 peptide combined with 250-mcg GM-CSF (Leukine) given intradermally monthly for six months.

Apthera hammered out a special protocol agreement with the FDA in 2009 after a 21-month process. It calls for a single, Phase III trial enrolling 700 women diagnosed with HER2/neu-expressing tumors who have completed standard-of-care treatment – surgery, chemotherapy and radiotherapy. Patients also must have a common HLA haplotype, specifically HLA-A2 or -A3. (See BioWorld Today, June 26, 2009.)

The primary endpoint will be disease-free survival, with the first analysis of data expected to occur after 70 recurrence events, or about three years after the start of the trial.

RXi's clinical trial update on Monday removed some of the last obstacles to initiation of the trial. The FDA removed its partial hold on CMC because the company has satisfied all of the requirements set forth by the agency. RXi has also created a material manufacturing plan so that it can stay on schedule for a planned start of the Phase III (PRESENT) trial in the first half of 2012.

In addition, the conditional institutional review board gave approval for two trial sites, with anticipated opening of international sites in the near future. The trial will ultimately run at 100 sites in the U.S., Canada and Europe. RXi also has engaged a clinical research organization to manage the trial and clinical operations.

Ahn said RXi plans to "meet or exceed" its target of starting the first patient in the first half of 2012.

According to Ahn, the field is wide open for NeuVax, as it will be the first breast cancer vaccine in Phase III trials. "Right now the standard of care is watching and waiting," he said. The trial will test NeuVax against placebo, highlighting the lack of competition in the market.

RXi stock rose 14 cents, to close at $1.14 Monday.

There may be significant room for improvement. Analyst Joseph Pantginis, of Roth Capital Partners, gave it a price target of $5.

"We believe that RXi's current valuation does not take into consideration the new opportunity with NeuVax and that RXi is still valued for its preclinical stage RNAi platform," Pantginis wrote.