CORRESP

January 31, 2013

VIA EDGAR

Securities and Exchange Commission

Division of Corporation Finance

100 F. Street, N.E.

Washington, D.C. 20549

Attention: Jeffrey Riedler

Re: KaloBios Pharmaceuticals, Inc.

Registration Statement on Form S-1 (File No. 333-184299)

Request for Acceleration of Effective Date

Dear Mr. Riedler:

Pursuant to Rule 461 under the Securities Act of 1933, as amended, KaloBios Pharmaceuticals, Inc. (the “Registrant”) hereby requests acceleration of the effective date of the above-referenced Registration Statement on Form S-1 (File No. 333-184299) (as amended, the “Registration Statement”), so that it may become effective at 9:00 a.m. Eastern Time on January 31, 2013, or as soon thereafter as practicable. By separate letter, the representatives of the underwriters of the issuance of the securities being registered join this request for acceleration.

The Registrant hereby acknowledges that:

(i) should the Securities and Exchange Commission (the “Commission”) or the staff (the “Staff”), acting pursuant to delegated authority, declare the Registration Statement effective, it does not foreclose the Commission from taking any action with respect to the Registration Statement;

(ii) the action of the Commission or the Staff, acting pursuant to delegated authority, in declaring the Registration Statement effective, does not relieve the Registrant from its full responsibility for the adequacy and accuracy of the disclosure in the Registration Statement; and

(iii) the Registrant may not assert comments of the Commission or the Staff and the declaration of effectiveness of the Registration Statement as a defense in any proceeding initiated by the Commission or any person under the federal securities laws of the United States.

[Signature Page Follows]

Sincerely, KaloBios Pharmaceuticals, Inc.
By:	/s/ David W. Pritchard
	David W. Pritchard President and Chief Executive Officer

2

CORRESP

Leerink Swann LLC

One Federal Street, 37^th Floor

Boston, MA 02110

January 31, 2013

VIA EDGAR

Securities and Exchange Commission

Division of Corporation Finance

100 F Street, N.E.

Washington, D.C. 20549

Attention: Jeffrey Riedler

Re: KaloBios Pharmaceuticals, Inc.

Registration Statement on Form S-1 (File No. 333-184299)

Request for Acceleration of Effective Date

Dear Mr. Riedler:

Pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended (the “Securities Act”), we, as the Representative of the several underwriters (the “Representative”), hereby join in the request of KaloBios Pharmaceuticals, Inc. (the “Registrant”), for the acceleration of the effective date of the Registrant’s Registration Statement on Form S-1 (File No. 333-184299) (as amended, the “Registration Statement”), relating to a public offering of shares of the Registrant’s common stock, par value $0.001 per share, so that the Registration Statement may be declared effective on January 31, 2013, at 9:00 a.m. Eastern Time, or as soon thereafter as practicable. We, as the Representative of the underwriters, confirm that the underwriters are aware of their obligations under the Securities Act.

Pursuant to Rule 460 promulgated under the Securities Act, we wish to advise you that we have distributed approximately 1,268 copies of the preliminary prospectus issued January 15, 2013 through the date hereof, as follows: 250 to prospective underwriters; 840 to institutional investors and 178 to others.

We, as the Representative of the underwriters, hereby represent on behalf of the underwriters that the underwriters are acting in compliance and will act in compliance with the provisions of Rule 15c2-8 promulgated under the Securities Exchange Act of 1934, as amended, in connection with the above proposed offering.

[Signature Page Follows]

Very truly yours,
LEERINK SWANN LLC
As Representative of the several Underwriters
By: LEERINK SWANN LLC
By:	/s/ Bryan Giraudo
	Name: Bryan Giraudo
	Title: Managing Director

[Signature Page to Acceleration Request Letter]