Tanks in the buffer holding room at Alexion Pharmaceuticals in Smithfield are one step in the process for making the drug Soliris, which currently has one approved use, treating a rare disease.

The Providence Journal / Mary Murphy

It is still a one-hit wonder, dependent upon a single drug that treats a rare illness.

But Alexion Pharmaceuticals, the Connecticut drug maker building its first production plant in Smithfield, may soon have a bigger audience for the sole product in its catalog.

Earlier this month, researchers presented preliminary findings from a study at the Mayo Clinic in Minnesota demonstrating that Alexion’s drug Soliris helps patients accept kidney transplants even when they have antibodies guarding against the donor tissue.

The drug inhibits part of the immune process that damages transplanted kidneys, protecting the organ by disabling the so-called complement system, an immune response that controls tissue destruction.

“These results are great news because they mean that none of the treated patients developed the most serious complication that normally threatens the transplant,” the lead author of the study, Mark Stegall, said in a statement after presenting the results at the American Transplant Congress in Boston. “This represents a quantum leap in this area.”

Soliris performs a similar function for patients with paroxysmal nocturnal hemoglobinuria, or PNH, a disease that causes a patient’s immune system to destroy red blood cells, leading to severe anemia and blood clots.

For now, that is the only approved use, and the patient pool is exceedingly small. But because Soliris is the only treatment for these patients, Alexion has been able to generate consistently strong revenue.

In the first three months of 2009, the company reported $14.5 million in net income, up from a $4.2-million loss in the first quarter of 2008. Soliris sales brought in $81.3 million, almost double the $45.5 million the drug generated in the same period in 2008.

The U.S. Food and Drug Administration approved Soliris in March 2007, and it earned a go-ahead from the European Commission in June of that year.

In 2009, Alexion has received permission to sell Soliris in Canada and Australia. In April, it submitted an application to market Soliris in Japan. Health authorities there have already classified the medication as an “orphan drug,” meaning Alexion would have a 10-year monopoly if Soliris is approved.

Last Wednesday, Alexion announced that Soliris had received the 2009 Prix Galien France Award in the category of medicines for rare diseases.

PNH is so rare that many doctors miss the symptoms, which typically begin when patients are in their early 30s. So Alexion has invested heavily in teaching oncologists and hematologists about the disease and pushing for regular testing of high-risk patients.

It has also sponsored studies to demonstrate more effective techniques for identifying PNH sufferers. In May, the company said a study that used a new high-sensitivity test found PNH cells in a majority of patients with bone marrow failure syndromes.

Lately, however, Alexion has also been focusing on expanding the uses for Soliris for other diseases that cause the immune system to malfunction.

It has begun four clinical studies, for example, that use Soliris to treat patients with atypical hemolytic uremic syndrome, or AHUS.

“We’re driving hard now our clinical development of the product in that disease,” Stephen P. Squinto, Alexion’s head of research, said in an interview. “We tend to look at our drug Soliris as a pipeline unto itself.”

Michael Aberman, a biotechnology analyst for Credit Suisse, sees big sales potential from AHUS. “We would be aggressive buyers of Alexion,” he said in a May 26 research note.

Alexion is also studying the potential use of Soliris for treating dense deposit disease, as well as the neurological diseases myasthenia gravis and multifocal motor neuropathy.

In a research note on June 8, Morgan Stanley analyst Sapna Srivastava said Soliris may also prove effective for heart transplant patients. “Success in additional indications,” Srivastava said, “could more than double Soliris’s potential.”

As it puts the finishing touches on its $116-million plant in Smithfield, Alexion also hopes to feed its drug pipeline.

One experimental drug produced in Smithfield, Anti-CD200, is already being tested in a study at several hospitals in the United States to treat patients with a form of leukemia who have not responded to chemotherapy.

Alexion has kept its headquarters in Connecticut, where on Thursday it plans to unveil 1,738 solar panels it installed on the rooftop of its office and research complex. But its investment in Rhode Island has been seen as a key success in efforts to expand the state’s health sciences sector.

There is ample capacity in the complex for producing Soliris, even if the patient pool grows significantly. But if other drugs prove successful they, too, would likely be produced in Rhode Island.

Alexion’s continued growth is considered especially vital because the state’s other major drug maker, Amgen, has been struggling in recent years.

State lawmakers say the industry has great potential.

The 2009 BioWorld Relocation and Expansion Guide, distributed at the BIO International Convention in May, named Rhode Island one of six “Biotech Hubs” in North America for the third year in a row.

Describing Rhode Island as a “small state with a big appetite for biotech,” the guide praised the state’s research and development tax credits as well as its location.

Rhode Island’s proximity to “the East Coast biotech universe couldn’t be more strategically well-placed,” the publication says. It also cites “its comparatively less expensive cost-of-living and less stressful milieu” that “allows businesses to go about their business, but in a more tranquil setting.”

bgedan@projo.com