SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 12b-25 Commission File Number 0-26422 NOTIFICATION OF LATE FILING (Check One): |X| Form 10-K |_| Form 11-K |_| Form 20-F |_| Form 10-Q |_| Form N-SAR For Period Ended: March 31, 1999 [ ] Transition Report on Form 10-K [ ] Transition Report on Form 20-F [ ] Transition Report on Form 11-K [ ] Transition Report on Form 10-Q [ ] Transition Report on Form N-SAR For the Transition Period Ended: --------------------------------- Nothing in this form shall be construed to imply that the Commission has verified any information contained herein. If the notification relates to a portion of the filing checked above, identify the Item(s) to which the notification relates: NOT APPLICABLE - -------------------------------------------------------------------------------- PART I - REGISTRANT INFORMATION DISCOVERY LABORATORIES, INC. - -------------------------------------------------------------------------------- Full Name of Registrant ANSAN PHARMACEUTICALS, INC. - -------------------------------------------------------------------------------- Former Name if Applicable 350 South Main Street, Suite 307 - -------------------------------------------------------------------------------- Address of Principal Executive Office (Street and Number) Doylestown, PA 18901 - -------------------------------------------------------------------------------- City, State and Zip Code

PART II - RULES 12b-25(b) AND (c) If the subject report could not be filed without unreasonable effort or expense and the registrant seeks relief pursuant to Rule 12b-25(b), the following should be completed. (Check appropriate box.) |X| Yes |_| No |X| (a) The reasons described in reasonable detail in Part III of this form could not be eliminated without unreasonable effort or expense; |X| (b) The subject annual report, semi-annual report, transition report on Form 10-K, 20-F, 11-K or N-SAR, or portion thereof, will be filed on or before the 15th calendar day following the prescribed due date; or the subject quarterly report or transition report on Form 10-Q, or portion thereof will be filed on or before the fifth calendar day following the prescribed due date; and |_| (c) The accountant's statement or other exhibit required by Rule 12b-25(c) has been attached if applicable. PART III - NARRATIVE State below in reasonable detail the reasons why Form 10-K, 11-K, 20-F, 10-Q, N-SAR, or the transition report or portion thereof, could not be filed within the prescribed time period. The registrant has been negotiating a financing which is expected to be completed on March 31, 1999. The registrant could not incorporate the description of this transaction into its Form 10-K by March 31, 1999 and file the transaction documents that will be required to be filed as exhibits to the Form 10-K by March 31, 1999 without unreasonable effort and expense. PART IV - OTHER INFORMATION (1) Name and telephone number of person to contact in regard to this notification Kenneth G. Alberstadt (212) 299-8640 - --------------------- ------------------------------ (Name) (Area Code) (Telephone Number) (2) Have all other periodic reports required under Section 13 or 15(d) of the Securities Exchange Act of 1934 or Section 30 of the Investment Company Act of 1940 during the preceding 12 months or for such shorter period that the registrant was required to file such report(s) been filed? If answer is no, identify report(s). |X| Yes |_| No

(3) Is it anticipated that any significant change in results of operation for the corresponding period for the last fiscal year will be reflected by the earnings statements to be included in the subject report or portion thereof? |_| Yes |X| No If so: attach an explanation of the anticipated change, both narratively and quantitatively, and, if appropriate, state the reasons why a reasonable estimate of the results cannot be made. DISCOVERY LABORATORIES, INC. -------------------------------------------- (Name of Registrant as Specified in Charter) has caused this notification to be signed on its behalf by the undersigned hereunto duly authorized. Date March 31, 1999 By /s/ Robert J. Capetola -------------- ---------------------- Robert J. Capetola, Ph.D. President and Chief Executive Officer Instruction: The form may be signed by an executive officer of the registrant or by any other duly authorized representative. The name and title of the person signing the form shall be typed or printed beneath the signature. If the statement is signed on behalf of the registrant by an authorized representative (other than an executive officer), evidence of the representative's authority to sign on behalf of the registrant shall be filed with the form. ATTENTION - -------------------------------------------------------------------------------- Intentional misstatements or omissions of fact constitute Federal criminal violations. (See 18 U.S.C. 1001) - --------------------------------------------------------------------------------