UPDATED: Alkermes reveals PhII success with antidepressant in blockbuster CNS plan

Alkermes ($ALKS) has a shot at offering a new option for treating depression in patients who don't respond to existing drugs. The company revealed positive preliminary data from a Phase II study of ALKS 5461, an opioid-receptor targeting drug, which the biotech player now aims to march into pivotal development.

On the back of the news, the Ireland-based company's stock had jumped 9.8% to $28.11 as of late this morning. 

The antidepressant is a major piece of Alkermes CEO Richard Pops' plan to bring a menu of internally developed CNS drugs to market, building on a healthy stream of royalty revenue from Johnson & Johnson's ($JNJ) long-acting antipsychotics and other products that use his company's formulation technology. CNS drug trials have some of the slimmest chances of success in the pharma industry, yet Pops has accepted risk in his pipeline in return for major growth prospects from a potential winner or two. And he's even talked about Alkermes offering up its own blockbusters.

In the Phase II study of 5461, Alkermes reported, results show that the treatment reduced symptoms of depression as quantified with a range of standard measures of the illness. The trial tested two daily doses of the drug for four weeks and involved 142 patients who remained depressed after taking mainstay antidepressants from the SSRI and SNRI drug classes. Despite a growing number of low-cost generics for depression, Alkermes says that most of the millions of patients with depression fail to respond to initial treatments. Its compound also manages to impact opioid receptors, which have long been targeted to combat the blues, without patients forming addictions to the treatment.

"The improvements in depressive symptoms observed in patients treated with ALKS 5461 in this study were clinically meaningful and among the most robust I have seen in a phase 2 study for depression in the past two decades," said Dr. Maurizio Fava, director of the depression clinical and research program at Massachusetts General Hospital, in a statement.

Alkermes plans to meet with the FDA with the Phase II results in hand before embarking on a late-stage trial of the drug. Later this year the company also plans to reveal late-stage data on ALKS 9070, a long-acting version of Abilify and the lead experimental candidate in the company's pipeline. Cowen & Co. analysts have projected that both drugs could bring in more than $500 million in annual sales.

"I think it's a critical component of that strategy," Pops told FierceBiotech of the 5461 program. He noted that the CNS pipeline could have two pivotal-stage programs with 5461 and 9070.

Yet Alkermes faces the challenge of replicating results from mid-stage work on 5461 in a larger late-stage study, which is never an easy thing to do in the depression field. This reality was apparent last year after Targacept and AstraZeneca struck out in four Phase III studies of their antidepressant TC-5214.

Alkermes plans to present further details from its Phase II study of 5461 at a medical meeting in May.

- here's the release

Editor's note: Updated with comments from CEO Richard Pops.