Consolidated Balance Sheets - USD ($)	Sep. 30, 2019	Sep. 30, 2018
CURRENT ASSETS
Cash and cash equivalents	$ 221,804,128	$ 30,133,213
Accounts receivable	661,361	327,375
Prepaid expenses	3,317,999	1,267,717
Other current assets	2,563,435	640,117
Short-term investments	36,899,894	46,400,176
TOTAL CURRENT ASSETS	265,246,817	78,768,598
Property and equipment, net	23,214,899	13,935,425
Intangible assets, net	17,063,580	18,764,010
Long-term investments	44,175,993
Other assets	144,148	141,918
TOTAL ASSETS	349,845,437	111,609,951
CURRENT LIABILITIES
Accounts payable	7,649,921	2,806,098
Accrued expenses	6,504,729	5,043,087
Accrued payroll and benefits	4,955,887	3,937,605
Deferred rent	173,952	307,334
Deferred revenue	77,769,629	600
Note payable		223,820
Other current liabilities	16,561	46,407
TOTAL CURRENT LIABILITIES	97,070,679	12,364,951
LONG-TERM LIABILITIES
Deferred rent, net of current portion	3,703,364	1,702,801
Deferred revenue, net of current portion	5,035,142
Note payable, net of current portion		2,101,198
Other non-current liabilities		200,000
TOTAL LONG-TERM LIABILITIES	8,738,506	4,003,999
Commitments and contingencies (Note 7)
Arrowhead Pharmaceuticals, Inc. stockholders' equity:
Common stock, $0.001 par value; 145,000,000 shares authorized; 95,506,271 and 88,505,302 shares issued and outstanding as of September 30, 2019 and September 30, 2018, respectively	187,876	180,875
Additional paid-in capital	664,086,155	582,902,694
Accumulated other comprehensive income (loss)	(391,624)	(21,564)
Accumulated deficit	(419,290,967)	(487,265,816)
Total Arrowhead Pharmaceuticals, Inc. stockholders' equity	244,591,440	95,796,189
Noncontrolling interest	(555,188)	(555,188)
TOTAL STOCKHOLDERS’ EQUITY	244,036,252	95,241,001
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 349,845,437	$ 111,609,951