May 5, 2016




Securities and Exchange Commission

Division of Corporation Finance

100 F Street, NE

Washington, D.C. 20549


Attention:Suzanne Hayes
 Re:     Oncobiologics, Inc. Registration Statement No. 333-209011



Ladies and Gentlemen:


Reference is made to our letter, filed as correspondence via EDGAR on May 4, 2016, in which we requested the acceleration of the effective date of the above-referenced Registration Statement for May 5, 2015 at 4:00 p.m. Eastern time in accordance with Rule 461 of the Securities Act of 1933, as amended.


As representatives of the several underwriters of the proposed public offering, we hereby respectfully withdraw our request for acceleration of the effectiveness of the above-referenced Registration Statement set forth in our May 4, 2016 letter.








  Very truly yours,
  By:  /s/ Ashley Delp Walker
    Name: Ashley Delp Walker
Title: Managing Director


  By:  /s/ Victoria Hale
    Name: Victoria Hale
Title: Vice President







cc:Pankaj Mohan, Oncobiologics, Inc.
  Lawrence Kenyon, Oncobiologics, Inc.
  Stuart M. Cable, Goodwin Procter LLP
  Edwin O’Connor, Goodwin Procter LLP
  Seo Salimi, Goodwin Procter LLP
  Yvan-Claude Pierre, Cooley LLP
  Daniel I. Goldberg, Cooley LLP
  Marianne Sarrazin, Cooley LLP








[Signature Page to Withdrawal of Underwriters’ Acceleration Request]