Threshold Pharmaceuticals, Inc.

170 Harbor Way, Suite 300

South San Francisco, CA 94080

November 12, 2015

Via EDGAR

Division of Corporation Finance

U.S. Securities and Exchange Commission

100 F Street, N.E.

Washington, D.C. 20549

Attn:	Suzanne Hayes
	Tara Keating Brooks

Re:	Threshold Pharmaceuticals, Inc.
	Registration Statement on Form S-3
	Filed November 2, 2015
	File No. 333-207745

Ladies and Gentlemen:

Pursuant to Rule 461 under the Securities Act of 1933, as amended, the undersigned registrant hereby requests that the U.S. Securities and Exchange Commission (the “Commission”) take appropriate action to cause the above-referenced Registration Statement on Form S-3 to become effective at 4:00 p.m. Eastern Time on November 16, 2015, or as soon thereafter as is practicable.

The undersigned registrant hereby acknowledges that:

· should the Commission or its staff, acting pursuant to delegated authority, declare the filing effective, it does not foreclose the Commission from taking any action with respect to the filing;

· the action of the Commission or its staff, acting pursuant to delegated authority, in declaring the filing effective, does not relieve the registrant from its full responsibility for the adequacy and accuracy of the disclosure in the filing; and

· the registrant may not assert staff comments and the declaration of effectiveness as a defense in any proceeding initiated by the Commission or any person under the federal securities laws of the United States.

Very truly yours,

Threshold Pharmaceuticals, Inc.

By:	/s/ Joel A. Fernandes
	Joel A. Fernandes
	Vice President, Finance and Controller