So far, the drug agency has approved only two products that qualify as gene therapy Kymriah, from Novartis, and Yescarta, made by Kite Pharma. Both treatments involve genetically altering a patients own immune cells to fight leukemia or lymphoma. An advisory panel to the F.D.A. recommended approval for a third product, made by Spark Therapeutics, to correct a gene defect that causes a blinding hereditary eye disease. All three agency actions occurred this year.

Such treatments are extremely expensive, costing hundreds of thousands of dollars.

The prospect of faster approvals disturbs Michael Carome, director of Public Citizens health research group, an advocacy organization. Dr. Carome believes that the industry, still quite young, needs careful F.D.A. oversight.

I think there is excessive hype, Dr. Carome said. We are talking about rushing to market very complex biologics products where we are still in the infancy of this field.

The agencys announcements included two final guidelines and two drafts that will be open for public comment. They are designed to help developers sort out whether they need to submit a licensing application to the F.D.A. to get approval for their treatments or fall into a lower risk category, which does not need premarket approval.

One of the proposals would be a boon to small clinics and independent researchers. It would permit them to apply as a group and to pool data. If approved, each would end up with a license for biologics, a category that refers to treatments like cell, tissue and gene therapies that come from natural sources rather than being chemically synthesized.

The guidelines also detail steps to rein in the hundreds of stem-cell clinics that treat ailments by liposuctioning belly fat from patients and processing it to extract so-called stem cells, which are then injected back into the patients. These largely unregulated procedures have been offered for arthritic knees, back pain, heart disease and other problems.

Several patients have been blinded after fat-derived cells were injected into their eyes.

Practitioners who perform these procedures have argued that they do not come under the agencys jurisdiction. But the new guidance suggested that at least some of the fat-derived injections will be more tightly controlled by the F.D.A. The document stated that if the fat tissue is processed specifically to isolate stem cells as the stem-cell clinics do then the procedures must meet F.D.A. safety requirements.

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F.D.A. Speeds Review of Gene Therapies, Vowing to Target ...