Two big biotechnology companies announced on Thursday that they would buy smaller companies that are harnessing novel technologies to develop drug treatments for leukemias and lymphomas.

Amgen said it would buy Micromet for $11 a share in cash, or a total of $1.16 billion, representing a 33 percent premium on Micromet’s closing price on Wednesday.

Celgene said it would buy the privately held Avila Therapeutics for $350 million in cash plus possible milestone payments that could total $575 million.

Related Links Amgen to Buy Micromet for $1.16 Billion

The deals show that leading biotechnology companies, like the larger traditional pharmaceutical companies, are eager to bolster their pipelines through acquisitions or licensing deals.

Micromet’s leading drug candidate, blinatumomab, is in phase 2 testing, the middle stage of clinical trials, as a treatment for acute lymphoblastic leukemia.

Axel Koester for The New York Times

The drug, and others Micromet is developing, utilizes the company’s bispecific T cell engager, or BiTE, technology. These are antibodies that bind to both a tumor and to a T cell of the immune system. Once the T cell is close to the tumor, it can kill it.

Micromet has its headquarters in Rockville, Md., but has its research and development in Munich, where the company was started.

The boards of both Amgen and Micromet have unanimously approved the transaction. Amgen was advised by Moelis & Company and the law firm Sullivan & Cromwell. Micromet was advised by Goldman Sachs and the law firm Cooley.

Amgen, with revenue of about $15 billion, is the world’s largest independent biotechnology company. But its growth has slowed in recent years as it has become reliant on maturing products while struggling to develop new blockbusters.

Jim Birchenough, an analyst with BMO Capital Markets who follows Amgen, called the move “a welcome positive step toward building longer-term sustainable growth,” though he said Amgen would still need to do more deals to sustain growth beyond 2015.

But Robyn Karnauskas of Deutsche Bank said that Micromet’s focus on hematologic tumors was “outside of Amgen’s core expertise’’ of solid tumors and supportive cancer care and that blinatumomab might take longer than expected to win regulatory approval.

Celgene is already a leading supplier of drugs for hematological cancers, known most for its blockbuster Revlimid for treating multiple myeloma. So its acquisition of Avila is right in its core area.

Avila, based in Bedford, Mass., is developing so-called targeted covalent drugs, which are oral drugs that potentially can form a bond with proteins in a way that silences them more effectively than do more conventional pills.

Avila’s most advanced drug candidate, AVL-292, is still in phase 1 clinical trials, the earliest stage of testing on people.

The drug inhibits the activity of a protein called Bruton’s tyrosine kinase, or Btk. Inhibiting that protein might slow diseases that involve rampant activity of immune system B cells, like non-Hodgkin’s lymphoma, and B-cell chronic lymphocytic leukemia, but also possibly rheumatoid arthritis and some other autoimmune diseases.

Last month Johnson & Johnson agreed to pay $150 million initially and up to $825 million later, for rights to a Btk inhibitor being developed by Pharmacyclics.

Under the terms of the Avila deal, which was agreed to by both boards, Celgene will pay up to $195 million in future milestones contingent on the development and approval of AVL-292, and up to $380 million in milestones contingent upon development and approval of other drug candidates.

Celgene said it expected the transaction would be neutral to its 2012 earnings, excluding special items.

The acquisition will provide a handsome return to Avila’s backers, which put $51 million into the company in two rounds of venture financing starting in 2007. Those backers were the venture capital firms Abingworth, Advent Venture Partners, Atlas Venture, Novartis Option Fund and Polaris Venture Partners. Acquisitions, as opposed to initial public offerings, are becoming the preferred exit routes for life sciences venture capitalists.