Arrowhead Subsidiary Calando Pharmaceuticals Enters into License Agreement with Cerulean Pharma Inc.

- Calando To License Cyclosert™ Platform and Associated IT-101 Drug Candidate for Upfront Payment of $2.4 Million, Milestone Payments and Royalties from Product Sales; Agreement Creates Substantial Potential Revenue Stream -

Arrowhead to Transfer to The NASDAQ Capital Market

PASADENA, Calif. — (BUSINESS WIRE) — Arrowhead Research Corporation (NASDAQ:ARWR) announced today that its application to transfer the listing of its common stock from The NASDAQ Global Market to The NASDAQ Capital Market has been approved. The transfer will be effective at the opening of business on Monday, March 9, 2009 and the Company’s common stock will continue to trade under the symbol "ARWR".

Arrowhead CEO Comments on Recent Nasdaq Letter

PASADENA, Calif. — Arrowhead Research Corporation’s (NASDAQ: ARWR) (“the Company”) President and Chief Executive Officer today issued the open letter to the Company’s shareholders.

Arrowhead Receives Notification of Minimum Stockholders’ Equity Non-Compliance from the Nasdaq Stock Market

PASADENA, Calif.—Arrowhead Research Corporation (NASDAQ: ARWR) announced today that it has received a letter from The Nasdaq Stock Market (NASDAQ) notifying the Company that, based on its Form 10-Q for the period ended December 31, 2008, Nasdaq has determined that Arrowhead’s stockholders' equity does not comply with the minimum $10,000,000 stockholders' equity requirement for continued listing on The Nasdaq Global Market. The Nasdaq notification does not effect on the listing of Arrowhead’s common stock at this time.

Arrowhead Reports First Quarter Fiscal 2009 Financial Results

Arrowhead's Majority Owned Subsidary, Unidym, Inc. Consolidates Operations

PASADENA, Calif. — January 26, 2009 — Arrowhead Research Corporation (Nasdaq: ARWR) announced today that its majority owned subsidiary, Unidym, Inc., has closed its Houston, Texas operation in order to consolidate its carbon nanotube (CNT) production capabilities with the rest of its operations in California’s Silicon Valley. This move was the latest in a series of steps taken to improve efficiencies implemented by Unidym’s newly appointed chief executive officer, Mark Tilley, Ph.D., who also serves as Arrowhead’s Vice President of Advanced Materials.