NEW YORK — A large clinical trial of a new osteoporosis drug found that it stimulates bone growth and prevents fractures at least as well as the only other such drug on the market.

The drug, expected to win approval from federal regulators, would offer another much-needed treatment for some of the 10 million Americans, 80 percent of them women, who have a disease that weakens bones and often leads to years of pain, disability, and early death.

Doctors said they hope the new drug would also spur price competition in an arena that has had none. The new drug would compete with a medicine made by Eli Lilly, called Forteo, that costs $2,550 for a four-week supply. A spokeswoman for Radius, the maker of the new drug, said it was the company’s policy not to discuss price.

Experts agree that new drugs are urgently needed. People with osteoporosis have bones that are fragile and break easily. Bone is naturally lost with age. But osteoporosis is an extreme, abnormal bone loss that can cause devastating fractures, particularly of the spine and hip.

Yet most patients, even those at highest risk, get no treatment, according to the National Osteoporosis Foundation.

The first treatment option, drugs called bisphosphonates, including Fosamax, slows bone loss but does not build bone. Those drugs can cost just pennies a day but can have very rare side effects — a sudden shattering of the thighbone or an erosion of the jawbone — that have discouraged people from using them.

The only other option is Forteo. But its price is so high that insurers have required, for example, that patients try a bisphosphonate first.

The clinical trial of the new drug was conducted by Radius, and the results published Tuesday in the Journal of the American Medical Association. The trial compared the new drug, abaloparatide, with a placebo and with Lilly’s drug, Forteo.

Like Forteo, the new drug must be injected daily, but is a derivative of a different hormone, one that stimulates only bone growth. Lilly’s drug stimulates bone growth and bone loss, but the net effect is a gain in bone.

With the Radius drug, holes in osteoporotic bone appeared to fill faster than with the Lilly drug. But the study was not large enough to determine whether that translated into fewer fractures. After 18 months, four women of the 824 taking the Radius drug had a new spine fracture, compared with six of the 818 taking Lilly’s drug and 30 of the 821 taking a placebo.

Osteoporosis is not one disease, and no one treatment will work for everyone, said Dr. Steven L. Teitelbaum, an osteoporosis expert at the Washington University School of Medicine.

Some patients have osteoporosis because they lose bone too quickly. For them, a bisphosphonate or a similar injected drug, Prolia, made by Amgen, is preferred. Those who make new bone too slowly need a drug that builds it. Until now the only such drug has been Forteo.

Patients generally take Forteo for only two years because it increased the incidence of bone cancer in rats. So far this effect has not been seen in people, said Dr. Henry M. Kronenberg, chief of the endocrine unit at Massachusetts General Hospital.