Los Angeles-based biotech CytRx Corp. is creating a majority owned subsidiary based in Massachusetts that will concentrate on commercializing gene silencing RNAi technology.

The Los Angeles-based drug developer said Tuesday that it will own 85 percent of the subsidiary, called RXi Pharmaceuticals Corp., with the new company’s scientific advisory team holding the remaining 15 percent.

CytRx has no products on the market but is in clinical trials on three traditional small-molecule compounds, including a treatment for Lou Gerig’s disease. Its RNAi program involved radically different technology, in partnership with the University of Massachusetts, that attempts to target the gene at the root of a disease and switch it off without affecting other genes or cells. The approach could provide cancer treatments with fewer side effects than chemotherapy, though the product most likely to go to market first is also a Lou Gerig’s treatment.

Tod Woolf, who was chief executive at RNAi developer Sequitur, will become chief executive at RXi Pharmaceuticals. The advisory team includes Craig C. Mello, who won the Nobel Prize in Medicine for his role in co-discovering RNAi.

Shares of CytRx jumped 28 cents, or more than 15 percent, to $2.08 on Tuesday.