SUPPLEMENTAL NON-CASH TRANSACTIONS	3 Months Ended
Dec. 31, 2012
SUPPLEMENTAL NON-CASH TRANSACTIONS	SUPPLEMENTAL NON-CASH TRANSACTIONS All Arrowhead share and per share amounts have been adjusted to reflect the 1 for 10 reverse stock split effected on November 17, 2011. On March 23, 2005, Arrowhead purchased 7,375,000 shares of Insert Therapeutics, Inc. common stock from two minority stockholders of Insert for 50,226 newly issued shares of Arrowhead Common Stock valued at $2,000,000 based on the closing market price of Arrowhead Common Stock on NASDAQ on the date of the closing. On March 31, 2006, Arrowhead purchased 964,000 shares of Calando Pharmaceuticals, Inc. common stock from minority stockholders of Calando for $1,928,000 consisting of 20,838 newly issued shares of Arrowhead Common Stock valued at $1,077,333 plus $850,667 in cash. The 20,838 shares of Arrowhead Common Stock were valued based on the average closing price of Arrowhead’s Common Stock on NASDAQ the ten trading days immediately prior to the date of the closing. On April 20, 2007, Arrowhead purchased shares of Series E Preferred Stock of Carbon Nanotechnologies, Inc. in exchange for 143,122 shares of Arrowhead Common Stock with an estimated fair market value of $5,400,000 based on the average closing price of Arrowhead’s Common Stock on NASDAQ the ten trading days immediately prior to March 24, 2007, as set forth in the Agreement and Plan of Merger among Unidym, Carbon Nanotechnologies, Inc., Arrowhead, and others. On April 23, 2008, Arrowhead purchased 200,000 shares of the Common Stock of Unidym Inc., in exchange for 7,054 shares of Arrowhead Common Stock with an estimated fair market value of $200,000 based on the average closing price of Arrowhead’s Common Stock on NASDAQ the ten trading days immediately prior to the date of the closing. On April 29, 2008, Arrowhead purchased all of the membership units of MASA Energy, LLC for $560,000. The purchase price consisted of 10,504 shares of Arrowhead Common Stock with an estimated fair market value of $310,000 based on the average closing price of Arrowhead’s Common Stock on NASDAQ the ten trading days immediately prior to the date of the closing, plus $250,000 in cash. On August 8, 2008, Unidym acquired all of the outstanding stock of Nanoconduction, Inc. in exchange for 11,411 shares of Arrowhead stock with an estimated fair market value of $250,000. On June 11, 2009, Arrowhead issued 132,462 shares of Common Stock with an estimated fair market value of $688,802 in exchange for an equal number of Series A Preferred Stock of Unidym, with minority stockholders of Unidym. On June 25, 2009, Arrowhead issued 194,444 shares of Common Stock with an estimated fair market value of $972,222 in exchange for an equal number of Series C Preferred Stock of Unidym, with a minority stockholder of Unidym. On September 22, 2009, Arrowhead issued 9,149 shares of Common Stock with an estimated fair market value of $46,662 in exchange for an equal number of Series A Preferred Stock of Unidym with a minority stockholder of Unidym. On September 28, 2009, Arrowhead issued 64,227 shares of Common Stock with an estimated fair market value of $398,209 in exchange for 5,574 shares of Series A Preferred Stock and 636,699 shares of Series C Preferred Stock of Unidym, with several minority stockholders of Unidym. On September 30, 2009, Arrowhead issued 27,777 shares of Common Stock with an estimated fair market value of $186,111 in exchange for an equal number of Series C-1 Preferred Stock of Unidym, with a minority stockholder of Unidym. In October and November 2009, Arrowhead issued 15,317 shares of Common Stock with an estimated fair market value of $47,485 in exchange for an equal number of shares of Series C Preferred Stock of Unidym, with several minority stockholders of Unidym. In October and November 2009, Arrowhead issued 114,000 shares of Common Stock with an estimated fair market value of $706,800 in exchange for 2,850,000 shares of Calando’s common stock, with several minority stockholders of Calando. In conjunction with the exchange, Arrowhead also issued 24,000 Warrants to purchase Arrowhead Common Stock in exchange for 600,000 Warrants to purchase Calando common stock. In February 2010, Arrowhead issued 8,000 shares of Common Stock and 2,400 warrants to purchase Arrowhead Common Stock, at an exercise price of $5.00, to several Calando shareholders, in exchange for 200,000 shares of Calando common stock and 60,000 warrants to purchase Calando common stock. In March 2010, a warrant holder exercised 24,788 warrants to purchase Arrowhead Common Stock, in a cashless exercise, whereby Arrowhead issued to the warrant holder 12,870 shares of Arrowhead Common Stock. In September 2010, Arrowhead issued warrants to purchase 390,625 shares of Arrowhead Common Stock, at an exercise price of $5.00, to two Calando shareholders, in exchange for 1,562.5 shares of Series A Preferred Stock of Calando Pharmaceuticals, Inc. On October 21, 2011, Arrowhead entered into a Stock and Asset Purchase Agreement whereby in acquired all of the outstanding common stock of Roche Madison Inc. and certain intellectual property rights in exchange for 1,288,158 shares of Arrowhead Common Stock, a promissory note of $50,000, and potential contingent consideration based on the achievement of certain regulatory milestones, and sales milestones and royalty payments after drug approval. On April 5, 2012, Arrowhead entered into a Stock Purchase Agreement whereby it acquired all of the outstanding common stock of Alvos Therapeutics, Inc. for 315,457 shares of Arrowhead Common Stock and potential contingent consideration based on the achievement of certain clinical, regulatory and sales milestones.

SUPPLEMENTAL NON-CASH TRANSACTIONS

All Arrowhead share and per share amounts have been adjusted to reflect the 1 for 10 reverse stock split effected on November 17, 2011.

On March 23, 2005, Arrowhead purchased 7,375,000 shares of Insert Therapeutics, Inc. common stock from two minority stockholders of Insert for 50,226 newly issued shares of Arrowhead Common Stock valued at $2,000,000 based on the closing market price of Arrowhead Common Stock on NASDAQ on the date of the closing.

On March 31, 2006, Arrowhead purchased 964,000 shares of Calando Pharmaceuticals, Inc. common stock from minority stockholders of Calando for $1,928,000 consisting of 20,838 newly issued shares of Arrowhead Common Stock valued at $1,077,333 plus $850,667 in cash. The 20,838 shares of Arrowhead Common Stock were valued based on the average closing price of Arrowhead’s Common Stock on NASDAQ the ten trading days immediately prior to the date of the closing.

On April 20, 2007, Arrowhead purchased shares of Series E Preferred Stock of Carbon Nanotechnologies, Inc. in exchange for 143,122 shares of Arrowhead Common Stock with an estimated fair market value of $5,400,000 based on the average closing price of Arrowhead’s Common Stock on NASDAQ the ten trading days immediately prior to March 24, 2007, as set forth in the Agreement and Plan of Merger among Unidym, Carbon Nanotechnologies, Inc., Arrowhead, and others.

On April 23, 2008, Arrowhead purchased 200,000 shares of the Common Stock of Unidym Inc., in exchange for 7,054 shares of Arrowhead Common Stock with an estimated fair market value of $200,000 based on the average closing price of Arrowhead’s Common Stock on NASDAQ the ten trading days immediately prior to the date of the closing.

On April 29, 2008, Arrowhead purchased all of the membership units of MASA Energy, LLC for $560,000. The purchase price consisted of 10,504 shares of Arrowhead Common Stock with an estimated fair market value of $310,000 based on the average closing price of Arrowhead’s Common Stock on NASDAQ the ten trading days immediately prior to the date of the closing, plus $250,000 in cash.

On August 8, 2008, Unidym acquired all of the outstanding stock of Nanoconduction, Inc. in exchange for 11,411 shares of Arrowhead stock with an estimated fair market value of $250,000.

On June 11, 2009, Arrowhead issued 132,462 shares of Common Stock with an estimated fair market value of $688,802 in exchange for an equal number of Series A Preferred Stock of Unidym, with minority stockholders of Unidym.

On June 25, 2009, Arrowhead issued 194,444 shares of Common Stock with an estimated fair market value of $972,222 in exchange for an equal number of Series C Preferred Stock of Unidym, with a minority stockholder of Unidym.

On September 22, 2009, Arrowhead issued 9,149 shares of Common Stock with an estimated fair market value of $46,662 in exchange for an equal number of Series A Preferred Stock of Unidym with a minority stockholder of Unidym.

On September 28, 2009, Arrowhead issued 64,227 shares of Common Stock with an estimated fair market value of $398,209 in exchange for 5,574 shares of Series A Preferred Stock and 636,699 shares of Series C Preferred Stock of Unidym, with several minority stockholders of Unidym.

On September 30, 2009, Arrowhead issued 27,777 shares of Common Stock with an estimated fair market value of $186,111 in exchange for an equal number of Series C-1 Preferred Stock of Unidym, with a minority stockholder of Unidym.

In October and November 2009, Arrowhead issued 15,317 shares of Common Stock with an estimated fair market value of $47,485 in exchange for an equal number of shares of Series C Preferred Stock of Unidym, with several minority stockholders of Unidym.

In October and November 2009, Arrowhead issued 114,000 shares of Common Stock with an estimated fair market value of $706,800 in exchange for 2,850,000 shares of Calando’s common stock, with several minority stockholders of Calando. In conjunction with the exchange, Arrowhead also issued 24,000 Warrants to purchase Arrowhead Common Stock in exchange for 600,000 Warrants to purchase Calando common stock.

In February 2010, Arrowhead issued 8,000 shares of Common Stock and 2,400 warrants to purchase Arrowhead Common Stock, at an exercise price of $5.00, to several Calando shareholders, in exchange for 200,000 shares of Calando common stock and 60,000 warrants to purchase Calando common stock.

In March 2010, a warrant holder exercised 24,788 warrants to purchase Arrowhead Common Stock, in a cashless exercise, whereby Arrowhead issued to the warrant holder 12,870 shares of Arrowhead Common Stock.

In September 2010, Arrowhead issued warrants to purchase 390,625 shares of Arrowhead Common Stock, at an exercise price of $5.00, to two Calando shareholders, in exchange for 1,562.5 shares of Series A Preferred Stock of Calando Pharmaceuticals, Inc.

On October 21, 2011, Arrowhead entered into a Stock and Asset Purchase Agreement whereby in acquired all of the outstanding common stock of Roche Madison Inc. and certain intellectual property rights in exchange for 1,288,158 shares of Arrowhead Common Stock, a promissory note of $50,000, and potential contingent consideration based on the achievement of certain regulatory milestones, and sales milestones and royalty payments after drug approval.

On April 5, 2012, Arrowhead entered into a Stock Purchase Agreement whereby it acquired all of the outstanding common stock of Alvos Therapeutics, Inc. for 315,457 shares of Arrowhead Common Stock and potential contingent consideration based on the achievement of certain clinical, regulatory and sales milestones.