Alder BioPharmaceuticals Presents Additional Data from Eptinezumab Development Program at 69th Annual American Academy of Neurology Meeting

- Eptinezumab rational design results in differentiated clinical profile for migraine prevention therapy -

- Eptinezumab responders showed significant and sustained reduction in migraine days following a single infusion - 

BOTHELL, Wash., April 24, 2017 -- Alder BioPharmaceuticals, Inc. (NASDAQ:ALDR), a clinical-stage biopharmaceutical company developing monoclonal antibody therapeutics, today presented additional data for eptinezumab (formerly ALD403), which is in Phase 3 clinical development for the prevention of migraine, at the 69^th Annual American Academy of Neurology (AAN) meeting in Boston.

"The data presented today at the AAN meeting add to the growing body of preclinical and clinical evidence supporting the differentiated delivery and clinical profile of eptinezumab as a potential treatment for the prevention of migraine," said Randall C. Schatzman, Ph.D., president and chief executive officer of Alder. “There is a high unmet need for preventative migraine treatments that meet patient needs and expectations.  We are very pleased with the emerging eptinezumab clinical profile from our data that sets a higher bar for efficacy and has correlated to meaningful improvements in quality of life measures.  We look forward to the top-line results from PROMISE 1, our first pivotal Phase 3 clinical trial, expected later this quarter.”

Key Points:
Poster presentation: “Rational Design of a Monoclonal Antibody (mAb) Inhibiting Calcitonin Gene-Related Peptide (CGRP), ALD403, Intended for the Prevention of Migraine”

• Eptinezumab (formerly ALD403) was uniquely designed to be delivered intravenously and target soluble CGRP ligand with high selectivity and affinity as characterized by a rapid on-rate and very slow off-rate.
• The rationale design of eptinezumab (formerly ALD403) enabled the selection of clinical characteristics that are important for the prevention of migraine which include rapid onset to clinical benefit, effectiveness and persistence.

Poster presentation: “75% Responder Rates Provide Improvement in HIT-6 Scores from Week 4 Through 12 Following a Single Infusion of ALD403, or Placebo”

• In a Phase 2b study of eptinezumab (formerly ALD403) in chronic migraine patients, significantly more subjects receiving eptinezumab achieved ≥75% or ≥50% response rate (RR) than placebo after a single IV infusion.
• Meaningful, rapid (1-4 weeks), and sustained (1-12 weeks) improvements in quality of life scores as measured by HIT‑6 scores were observed for patients in the study achieving ≥75% or ≥50 to <75% RR.
• All doses of eptinezumab (formerly ALD403) were well tolerated with no serious related adverse events reported.

About Alder BioPharmaceuticals
Alder BioPharmaceuticals, Inc., is a clinical-stage biopharmaceutical company that discovers, develops and seeks to commercialize genetically engineered therapeutic antibodies with the potential to meaningfully transform current treatment paradigms. Alder's lead pivotal-stage product candidate, eptinezumab (formerly ALD403), is being evaluated for migraine prevention. Eptinezumab is a monoclonal antibody that inhibits calcitonin gene-related peptide (CGRP), a protein that is active in mediating the initiation of migraine. Alder is additionally evaluating ALD1910, a preclinical product candidate also in development as a migraine prevention therapy. ALD1910 is a monoclonal antibody that inhibits pituitary adenylate cyclase-activating polypeptide-38 (PACAP-38), another protein that is active in mediating the initiation of migraine. Clazakizumab, Alder's third program, is a monoclonal antibody candidate that inhibits interleukin-6 and is licensed to Vitaeris, Inc. For more information, please visit http://www.alderbio.com.

Forward Looking Statements
This press release contains forward-looking statements, including, without limitation, statements relating to: the continued development and clinical, therapeutic and commercial potential of eptinezumab (formerly ALD403); the availability of results from clinical trials; the emerging differentiated delivery and clinical profile of eptinezumab; and the high unmet need for preventative migraine treatments.  Words such as “supporting,” “potential,” “need,” “pleased,” “emerging,” “sets,” “look forward,” “expected,” or other similar expressions, identify forward-looking statements, but the absence of these words does not necessarily mean that a statement is not forward-looking. In addition, any statements that refer to expectations, projections or other characterizations of future events or circumstances are forward-looking statements. The forward-looking statements in this press release are based upon Alder's current plans, assumptions, beliefs, expectations, estimates and projections, and involve substantial risks and uncertainties.  Actual results and the timing of events could differ materially from those anticipated in the forward-looking statements due to these risks and uncertainties as well as other factors, which include, without limitation: risks related to the potential failure of eptinezumab to demonstrate safety and efficacy in clinical testing; Alder's ability to conduct clinical trials and studies of eptinezumab sufficient to achieve a positive completion; the availability of data at the expected times; the clinical, therapeutic and commercial value of eptinezumab; risks and uncertainties related to regulatory application, review and approval processes and Alder's compliance with applicable legal and regulatory requirements; risks and uncertainties relating to the manufacture of eptinezumab; Alder's ability to obtain and protect intellectual property rights, and operate without infringing on the intellectual property rights of others; the uncertain timing and level of expenses associated with the development of eptinezumab; the sufficiency of Alder's capital and other resources; market competition; changes in economic and business conditions; and other factors discussed under the caption "Risk Factors" in Alder's Annual Report on Form 10-K for the year ended December 31, 2016, which was filed with the Securities and Exchange Commission (SEC) on February 23, 2017, and is available on the SEC's website at www.sec.gov.  Additional information will also be set forth in Alder's other reports and filings it will make with the SEC from time to time.  The forward-looking statements made in this press release speak only as of the date of this press release.  Alder expressly disclaims any duty, obligation or undertaking to release publicly any updates or revisions to any forward-looking statements contained herein to reflect any change in Alder's expectations with regard thereto or any change in events, conditions or circumstances on which any such statements are based. 

Media Contacts:
David Schull
Russo Partners, LLC
(212) 845-4271
[email protected]

Investor Relations Contact:
David Walsey
Alder BioPharmaceuticals Inc.
(425) 408-8032
[email protected]