ARROWHEAD RESEARCH CORP

Beneficial ownership report for a passive holder of more than 5% (Schedule 13G) (amendment)

General form for quarterly reports under Section 13 or 15(d)

Results of Operations and Financial Condition

Beneficial ownership report for a passive holder of more than 5% (Schedule 13G) (amendment)

Beneficial ownership report for a passive holder of more than 5% (Schedule 13G) (amendment)

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain Officers

General form for quarterly reports under Section 13 or 15(d)

Results of Operations and Financial Condition

Registration statement under Securities Act of 1933 to be offered to employees pursuant to certain plans

Beneficial ownership report for a passive holder of more than 5% (Schedule 13G)

Beneficial ownership report for a passive holder of more than 5% (Schedule 13G)

Beneficial ownership report for a passive holder of more than 5% (Schedule 13G)

Beneficial ownership report for a passive holder of more than 5% (Schedule 13G) (amendment)

Submission of Matters to a Vote of Security Holders

General form for quarterly reports under Section 13 or 15(d)

Results of Operations and Financial Condition

Annual Report Scanned (Paper)

Additional Information for Proxy Statement/ Votes

Definitive Proxy Statement

Entry into a Material Definitive Agreement

Entry into a Material Definitive Agreement

Prospectus Supplement for Primary Offering

Prospectus Supplement for Primary Offering

No description available

Free Writing Prospectus

Free Writing Prospectus

Prospectus Supplement for Primary Offering

Prospectus Supplement for Primary Offering

Regulation FD Disclosure

Automatic Shelf Registration

Annual report pursuant to Section 13 or 15(d)

Results of Operations and Financial Condition

Other Events

Annual report pursuant to Section 13 or 15(d) (amendment)

Other Events

Other Events

Entry into a Material Definitive Agreement

General form for quarterly reports under Section 13 or 15(d)

Results of Operations and Financial Condition

General form for quarterly reports under Section 13 or 15(d)

Results of Operations and Financial Condition

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain Officers

Submission of Matters to a Vote of Security Holders

No description available

General form for quarterly reports under Section 13 or 15(d)

Results of Operations and Financial Condition

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain Officers

Additional Information for Proxy Statement/ Votes

Annual Report Scanned (Paper)

Additional Information for Proxy Statement/ Votes

Definitive Proxy Statement

No description available

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain Officers

Annual report pursuant to Section 13 or 15(d)

General form for quarterly reports under Section 13 or 15(d)

General form for quarterly reports under Section 13 or 15(d)

Registration statement under Securities Act of 1933 to be offered to employees pursuant to certain plans

Additional Information for Proxy Statement/ Votes

General form for quarterly reports under Section 13 or 15(d)

Annual Report Scanned (Paper)

Additional Information for Proxy Statement/ Votes

Definitive Proxy Statement

Prospectus Supplement for Primary Offering

Annual report pursuant to Section 13 or 15(d)

General form for quarterly reports under Section 13 or 15(d)

Letter from the SEC

General form for quarterly reports under Section 13 or 15(d)

Correspondence with the SEC

Letter from the SEC

Registration statement under Securities Act of 1933 to be offered to employees pursuant to certain plans

Correspondence with the SEC

Letter from the SEC

General form for quarterly reports under Section 13 or 15(d)

Definitive Proxy Statement

Preliminary Proxy Statement

Automatic Shelf Registration

Annual report pursuant to Section 13 or 15(d)

General form for quarterly reports under Section 13 or 15(d)

General form for quarterly reports under Section 13 or 15(d)

Additional Information for Proxy Statement/ Votes

General form for quarterly reports under Section 13 or 15(d)

Definitive Proxy Statement

Registration statement under Securities Act of 1933 to be offered to employees pursuant to certain plans

Registration statement under Securities Act of 1933 to be offered to employees pursuant to certain plans

Letter from the SEC

Correspondence with the SEC

Definitive Proxy Statement

Letter from the SEC

Prospectus Supplement for Primary Offering

Registration statement under Securities Act of 1933 to be offered to employees pursuant to certain plans

Definitive Proxy Statement

Preliminary Proxy Statement

Prospectus Supplement for Primary Offering

Automatic Shelf Registration

Prospectus Supplement for Primary Offering

Registration statement under Securities Act of 1933 to be offered to employees pursuant to certain plans

No description available

Additional Information for Proxy Statement/ Votes

Definitive Proxy Statement

Letter from the SEC

Correspondence with the SEC

Letter from the SEC

Definitive Proxy Statement

Additional Information for Proxy Statement/ Votes

Correspondence with the SEC

Correspondence with the SEC

Definitive Proxy Statement

OLUKOTUN ADEOYE Y

PERRY MICHAEL S

OLUKOTUN ADEOYE Y

PERRY MICHAEL S

Cohen Matthew Gregory

Cohen Matthew Gregory

Apel Daniel Joseph

Lu Hongbo

Hamilton James C

Lu Hongbo

Lu Hongbo

Apel Daniel Joseph

Hamilton James C