Washington Editor

Pluristem Ltd. is getting more fuel for its PLacental eXpanded (PLX) cell pipeline in a $62 million licensing deal with United Therapeutics Corp.

Under the agreement to be signed Tuesday, Haifa, Israel-based Pluristem will get $7 million up front with $55 million in milestone and other payments. In exchange, United Therapeutics, of Silver Spring, Md., will receive exclusive worldwide licensing rights to develop and commercialize a PLX cell-based treatment for pulmonary hypertension (PH).

United Therapeutics will cover all the costs of the clinical trials for the PH indication. If the therapy is approved, the company will purchase commercial supplies from Pluristem at a specified margin over cost.

Pluristem also will receive royalties on gross profits. The agreement is expected to close by the end of August.

"This agreement is in line with our strategy of being a state-of-the-art cell manufacturer while maintaining all the production and intellectual property rights for future product candidates," Pluristem Chairman and CEO Zami Aberman said.

United Therapeutics may be the first of several biotechs to strike a licensing agreement with Pluristem. A number of companies have expressed interest in using the placenta-derived cells to develop therapies for various indications, Aberman said in a letter to shareholders last month.

That interest stemmed from the company's announcement of plans for a Phase II multinational trial of PLX therapies in intermittent claudication, a less severe form of peripheral artery disease (PAD), and a Phase II/III trial in critical limb ischemia (CLI). The primary endpoint of the pivotal CLIA study will be major-amputation-free survival after 12 months of follow-up.

The studies will begin once the protocol designs are finalized and approved. In both placebo-controlled studies, PLX-PAD cells will be injected twice, four months apart. The Phase II study is expected to enroll about 180 subjects, while the Phase II/III CLI study will enroll about 450 subjects.

Pluristem also is exploring other uses for its PLX cells, which are an "off-the-shelf" allogeneic therapy that requires no tissue matching. The company is moving into clinical development for muscle injury indications, following a preclinical study in Germany that demonstrated significant improvement in the recovery of muscle function in a mouse model.

In addition, Pluristem has established R&D partnerships with the New York University Medical Center for the study of PLX cells in the treatment of diabetic foot ulcers and with Hadassah University Medical Center to continue an animal study of the cells as a radiation sickness treatment.

With a full slate of clinical activities, Aberman expects the company's cash burn rate to increase over the next year. Pluristem had $44 million in cash as of March 31, which Aberman said should be sufficient to support the development activities through the end of 2013.

Much of that funding came from a public offering early this year, in which Pluristem raised more than $38 million. (See BioWorld Today, Jan. 28, 2011.)

Shares of Pluristem (NASDAQ:PSTI) were up 18 cents, closing at $3.15 Monday.