MannKind Corp. appears to be moving closer to marketing a drug that could help patients suffering from diabetes.

Founded by billionaire investor Alfred Mann, the Valencia-based pharmaceutical developer reported in a securities filing Friday that it informed the federal Food and Drug Administration it has designed two clinical trials to evaluate the efficacy and safety of its leading drug candidate, Afrezza.

“The study in patients with type 1 diabetes is now underway and the study in patients with type 2 diabetes will begin shortly,” the company statement said. “Subject to the timely enrollment of patients in these studies, we currently expect to complete both of these studies during 2012 and to submit the results as an amendment to our new drug application to the FDA by early 2013.”

Approval of Afrezza is considered vital to MannKind, which does not currently market any drug product. In August, the company posted losses of $44.5 million, or $0.37 per share based on 121.7 million shares, a further slip from year-ago losses of $42.3 million, or $0.37 per share based on 113.1 million shares.

Quarterly operating expenses climbed to $39.2 million from $37.4 million a year earlier, of which $30.3 million was for research and development versus $26.2 million for the same period in 2010.

MannKind describes Afrezza as a “novel, ultra rapid-acting mealtime insulin therapy in late stage clinical investigation for the treatment of adult patients with Type 1 and Type 2 diabetes mellitus for the control of hyperglycemia.”

“We believe that Afrezza is able to satisfy diabetes patients’ needs by being highly synchronized with the normal digestion of a typical meal,” the company says. “To date, the Afrezza clinical program has involved 56 different studies of Afrezza and over 5,300 adult patients.”

“In clinical trials that compared Afrezza to present state-of-the-art insulin treatment, Afrezza has shown a significant reduction in post-meal glucose fluctuations, which are believed to be an important risk factor in the development of complications; the ability to achieve comparable levels of overall glucose control; lower fasting glucose levels; a lower risk of hypoglycemia, which is considered to be a major problem for patients; less weight gain than is typically associated with other insulin treatments.”

“We believe that Afrezza has the potential to change diabetes therapy by offering significant benefits to the growing population of patients with diabetes,” the company says.