Shares of Advanced Cell Technology, Inc. (OTCBB: ACTC) advanced higher on Thursday following an announcement earlier this week that the U.S. Food and Drug Administration gave the company the green light to conduct clinical trials for a therapy made from embryonic stem cells in patients with Dry Age-Related Macular Degeneration (AMD), a common cause of vision loss.

“Dry AMD is the leading cause of blindness in individuals over the age of 55,” Dr. Robert Lanza, ACTC’s chief scientific officer, said in a statement. “As the population ages, the incidence of AMD is expected to double over the next 20 years, further exacerbating this unmet medical need.”

Age-Related Macular Degeneration has two predominant forms, wet and dry. Dry AMD is the most common form, accounting for almost 90 percent of all cases. The progress of Dry AMD includes a breakdown or thinning of the layer of RPE cells in the patient’s macula, the region at the center of the retina responsible for high acuity vision. Over time, the progressive loss of RPE cells and accompanying loss of photoreceptors can cause severe vision loss and even blindness.

This marks the second FDA approved trial for ACTC’s stem cell product. The first came in November when ACTC received FDA approval for the second human trial of human embryonic stem cells to treat people with Stargardt’s macular dystrophy, a progressive form of blindness.

“ACT is now the first company to receive FDA clearance for two hESC trials, and is now a true translational leader in the field of regenerative medicine,” said Gary Rabin, Interim Chairman and CEO of ACTC in a statement. “It marks a major step forward, not just within the stem cell sector, but, potentially for modern healthcare techniques. We plan to proceed into the clinic with both of our hESC-based programs as quickly as possible.”

Shares of ACTC are up as much as 420 percent over the past three months.