Westwood-based Puma Biotechnology has received a special drug designation from the federal Food and Drug Administration for one of its drug candidates for the treatment of small-cell lung cancer. 

The designation, known as “orphan drug” status, aims to spur the development of investigational therapies to treat, diagnose or prevent a rare disease or condition affecting fewer than 200,000 people in the United States. 

Developers of orphan drugs are then eligible for tax credits for qualified clinical trials, waivers of certain Food and Drug Administration fees and the potential for seven years of post-approval marketing exclusivity. 

Without such incentives, the concern is that pharmaceutical companies would avoid developing therapies for these rare diseases and conditions in favor of pursuing more common diseases that represent bigger markets.

Puma’s drug candidate targets small-cell lung cancer, an aggressive form of lung cancer with a poor prognosis and with limited treatment options, especially for patients whose chemotherapy was unsuccessful.

The drug itself, known as alisertib, is a selective, small-molecule inhibitor of aurora kinase, a group of enzymes that regulate the pace and volume of cell division. 

When these enzymes fail to function properly, the pace of cell division can increase and eventually lead to the formation and rapid growth of tumors that are often cancerous.

“Obtaining orphan drug designation from the FDA signifies our continued progress and commitment to the development of alisertib for the treatment of small-cell lung cancer,” Alan Auerbach, Puma’s founder and chief executive, said in the company’s announcement. “There is an urgent need for new treatments for patients with small-cell lung cancer, and we look forward to the initiation of our Phase II trial of alisertib in small-cell lung cancer.”

That clinical trial is set to begin before year’s end.