Perhaps the ultimate sign of a satisfied customer is a willingness to pay more than $1 billion for a company after using a product for six months. Having had a taste of Micromet Inc.'s BiTE antibody platform through a license agreement inked July 12, 2011, Amgen Inc., of Thousand Oaks, Calif., offered $1.16 billion to acquire the Rockville, Md.-based company.

Both companies' boards unanimously approved the $11 per share purchase, which will transfer ownership of the Micromet technology and pipeline to Amgen. That pipeline includes blinatumomab, a Phase II BiTE antibody that showed activity in acute lymphoblastic leukemia (ALL), and two Phase I candidates in solid tumors and gastrointestinal cancers.

In a conference call Thursday afternoon, Amgen's chief operating officer, Robert A. Bradway, called the acquisition of Micromet "an important strategic move." He added, "We're impressed with their lead molecule and the broader potential of their technology."

In addition to owning Micromet's assets, Amgen will be entitled to milestone and royalty payments from the company's existing licensees of BiTE and other technologies. Micromet's Munich, Germany, site will operate as an Amgen center of excellence.

The deal is being received as a validation of the BiTE platform and as a fair or somewhat high price. Micromet's stock (NASDAQ:MITI) surged $2.66, or 32 percent, to close at $10.94 Thursday.

Leerink Swann's Joshua Schimmer commented, "We like the MITI profile and see the assets as attractive, albeit at a price tag higher than we would have wanted to see."

Joseph Pantginis, of Roth Capital Partners, on the other hand, thought it was a fair price. "The tender offer price corresponds to our current price target, and fairly reflects Micromet's valuation, in our opinion," he wrote.

Deutsche Bank's Robyn Karnauskas had some concerns. "Our initial take is that this acquisition is outside of Amgen's core expertise of solid tumors, supportive cancer care, RA, dialysis or osteoporosis." She continued, "We recently met with Micromet management and took home that the regulatory pathway for blinatumomab was still uncertain. We are not sure if the product will receive accelerated approval from FDA."

Amgen's July license agreement with Micromet was valued at up to $976 million, with a $14 million up-front payment. The big biotech contracted with Micromet to develop BiTE antibodies to three solid tumor targets. (See BioWorld Today, July 12, 2011.)

It was the largest preclinical biotech deal of 2011 in terms of total potential dollars, although the up-front fee was on par with similar deals.

Micromet has existing licensing relationships with a number of major pharmaceutical companies, including Boehringer Ingelheim GmbH, Bayer Schering Pharma AG, Sanofi SA and AstraZeneca plc.

Micromet's BiTE antibody technology forms a new class of drugs that mobilize T cells. The antibodies are designed to enable T cells to detect and destroy normally unrecognizable cancer cells by binding with one arm to the cell surface protein CD3. The other arm binds the tumor target.

"This approach is powerful because cytotoxic T cells are remarkably active. Stimulation of these cells create a memory population that lasts a long time," said Roger M. Perlmutter, executive vice president of R&D at Amgen.

Piper Jaffray's Ian Somaiya noted that the acquisition makes strategic sense, but it may take some time for Amgen to realize the benefits.

Micromet is developing blinatumomab for ALL, a cancer of white blood cells that primarily affects children. The standard treatment is high-dose induction chemotherapy, which has cure rates of 80 percent. However, toxicity is a concern for patients so young.

In adult patients, chemotherapy is dramatically less effective. Response rates are lower, and relapse rates are higher.

Blinatumomab is designed to direct the body's T cells to attack CD19, an antigen present on the surface of B-cell-derived ALL and non-Hodgkin lymphoma.

At the American Society of Hematology meeting in December 2011, Micromet presented Phase II data showing blinatumomab more than doubled the complete remission rate produced by standard therapies in adults with relapsed or refractory B precursor ALL.

In the single-arm study, 68 percent of evaluable patients (17 of 25) across all tested doses and schedules achieved either a complete response (CR) or complete response with partial hematologic recovery (CRh). Of the 12 evaluable patients who received the selected dose and schedule, 75 percent (nine of 12) achieved a CR or CRh.

In a separate presentation, Micromet said Phase I data showed blinatumomab induced durable responses in patients with extensively pretreated diffuse large B-cell lymphoma. Of the 11 evaluable patients receiving the target dose of the drug, six (55 percent) achieved an objective response, including four patients who achieved a complete response.

Amgen's move is part of a developing trend of big pharma and big biotech acquisitions aimed at refilling dwindling pipelines through purchase of assets calculated to pay off in the short and long term.

Shares of Amgen (NASDAQ:AMGN) fell $1.13 to close Thursday at $68.08.