$ALDR Eptinezumab Reduces Migraine Risk Meets Primary and All Key Secondary Endpoints

— Highly statistically significant results with rapid prevention beginning Day One, 50%, 75%, 100% responder rates by month one sustained for three months —

— 15% of patients had no migraines for a full three months —

— Conference call and webcast to be held today, January 8, at 8:30 a.m. ET —
                                                                                                                                                   

BOTHELL, Wash., Jan. 08, 2018 —  Alder BioPharmaceuticals, Inc. (NASDAQ:ALDR), a biopharmaceutical company focused on developing novel therapeutic antibodies for the treatment of migraine, today announced that eptinezumab, its lead investigational product candidate for migraine prevention targeting calcitonin gene-related peptide (CGRP), met the primary endpoint in its pivotal Phase 3 PROMISE 2 clinical trial with very high statistical significance vs. placebo (p<0.0001) for both dose levels tested in the trial following a single quarterly infusion. In addition, eptinezumab met all key secondary endpoints with very high statistical significance vs. placebo including prevention beginning Day One (p<0.0001) and 50 percent (p<0.0001) and 75 percent (p<0.0001) responder rates month one through month three. Furthermore, 15% of eptinezumab patients had no migraines (i.e., 100 percent response) for a full three months (p<0.0001 unadjusted). Safety and tolerability were similar to previously reported eptinezumab studies.

“These clinically significant data clearly demonstrate that eptinezumab delivered by infusion provided rapid, effective and sustained migraine relief,” said Randall C. Schatzman, Ph.D., President and Chief Executive Officer of Alder. “With these PROMISE 2 results, we remain on track to submit our Biologics License Application (BLA) in the second half of 2018. If approved, eptinezumab has the potential to advance the treatment paradigm in chronic migraine prevention and be a meaningful treatment option for millions of the most severely impacted patients.”

PROMISE 2 Top-Line Results Following a Single Eptinezumab Administration

• Primary endpoint met: reduction of 8.2 monthly migraine days from baseline compared to 5.6 days for placebo, p<0.0001
• Key secondary and other endpoints met
  • Rapid Day One prevention: 52 percent reduction in migraine risk beginning Day One post-infusion compared to 27 percent for placebo, p<0.0001¹
  • Responder rates for month one through month three:
    • 61 percent of patients achieved 50 percent or greater reduction in migraine days from baseline compared to 39 percent for placebo, p<0.0001
    • 33 percent of patients achieved a 75 percent or greater reduction in migraine days from baseline, compared to 15 percent for placebo, p<0.0001
    • 15 percent of patients had no migraines (i.e., 100 percent response) for a full three months, compared to 5 percent for placebo, p<0.0001 (post hoc, unadjusted)
  • All other pre-specified key secondary endpoints were met with very high statistical significance

The observed safety profile in this study, to date, is consistent with previously reported eptinezumab studies. Adverse event rates among eptinezumab-treated subjects were similar to placebo-treated subjects. The most commonly reported adverse events for eptinezumab, occurring at an incidence of 2.0% or greater, were nasopharyngitis (common cold) (6.3 percent), upper respiratory infection (4.0 percent), nausea (3.4 percent) and urinary tract infection (3.1 percent), arthralgia (joint pain) (2.3 percent), dizziness (2.6 percent), anxiety (2.0 percent) and fatigue (2.0 percent). Full safety data will be available at the completion of the study.

“These results represent an important part of the significant step forward that patients who suffer from migraine, many of whom have been living with the disease for decades with limited relief, are about to experience,” said Peter Goadsby, M.D., Ph.D. D.Sc., Neurologist and Headache Specialist at the University of California, San Francisco Medical Center. “The new data demonstrate that eptinezumab administered via infusion delivers rapid onset and sustained benefit following one administration. Rapid onset of effect is a true paradigm shift in migraine preventive treatment. I’m excited about the potential for my patients to experience early and meaningful periods of migraine freedom if new treatments become approved.”

More than 2,600 patients have been treated with eptinezumab in its clinical development program, including the PROMISE 1 and PROMISE 2 trials. The eptinezumab development program was designed to redefine physician and patient expectations for migraine prevention, including rapid, meaningful, sustained migraine relief. Alder plans to submit a BLA to the U.S. Food and Drug Administration (FDA) for eptinezumab in the second half of 2018. If approved by the FDA, eptinezumab will be the first-to-market migraine prevention infusion therapy, with 100 percent of the treatment dose available upon administration.

About Eptinezumab PROMISE Clinical Trial Program
PROMISE 2 (PRevention Of Migraine via Intravenous ALD403 Safety and Efficacy 2) is a Phase 3, randomized, double-blind, placebo-controlled global trial evaluating the safety and efficacy of eptinezumab for chronic migraine prevention. In the study, 1,072 patients were randomized to receive eptinezumab (300 mg or 100 mg), or placebo administered by infusion once every 12 weeks. To be eligible for the trial, patients must have experienced at least 15 headache days per month, of which at least eight met criteria for migraine. Patients that participated in the trial had an average of 16.1 migraine days per month at baseline. The primary endpoint was the mean change from baseline in monthly migraine days over the 12 week, double-blind treatment period. Secondary study endpoints assessed through 12 weeks included reduction in migraine prevalence day 1 and days 1-28, reduction of at least 50%, 75%, and 100% from baseline in mean monthly migraine days, change from baseline in mean monthly acute migraine-specific medication days, and reductions from baseline in patient-reported impact scores on the Headache Impact Test (HIT-6).

PROMISE 1 (PRevention Of Migraine via Intravenous eptinezumab Safety and Efficacy 1) was a Phase 3 randomized, double-blind, placebo-controlled global trial evaluating the safety and efficacy of eptinezumab for episodic migraine prevention. In the study, 888 patients were randomized to receive eptinezumab (300 mg, 100 mg or 30mg), or placebo administered by infusion once every 12 weeks. To be eligible for the trial, patients must have experienced ≤14 headache days per month, of which at least four met the criteria for migraine. The primary endpoint was the mean change from baseline in monthly migraine days over the 12 week, double-blind treatment period. Full 24-week data from PROMISE 1 was presented at the 18th Congress of the International Headache Society in September 2017.

About Eptinezumab
Eptinezumab is a monoclonal antibody (mAb) inhibiting calcitonin gene-related peptide (CGRP), which is believed to play a key role in mediating and initiating migraine. Eptinezumab’s mAb design combined with delivery via quarterly infusion allows for strong and immediate inhibition of CGRP biology.² Eptinezumab is currently in multiple global, randomized pivotal, Phase 3 studies to assess its efficacy and safety in migraine prevention.

About Migraine^3,4,5
Migraine affects 36 million Americans and is considered the 6th most disabling disease in the world. It is a disabling neurological disease characterized by recurrent episodes of moderate to severe headache accompanied by nausea, vomiting, and sensitivities to light and sound. The occurrence of migraine can be unpredictable with a profound impact on activities of daily living. This disease can last decades, often during what should be the most productive years of patients³ lives. Migraine can remit or progress to chronic migraine over time and persist as chronic migraine for years or decades, but it commonly oscillates between periods of frequent episodic and chronic migraine. Current preventive treatments for migraine fail to meet the needs of most patients and most patients discontinue use within 6 months to 1 year due to lack of efficacy and/or side effects.^5,6 There is a significant need for new, effective, and well-tolerated treatment options.

Conference Call and Webcast
Alder will host a conference call and live audio webcast today at 8:30 a.m. ET to discuss the PROMISE 2 top-line data. The live call may be accessed by dialing (877) 430-4657 for domestic callers or (484) 756-4339 for international callers, and providing conference ID number 8388707. The webcast and accompanying slides may be accessed from the Events & Presentations page in the Investors section of Alder’s website at www.alderbio.com and will be available for replay following the call for at least 30 days.

About Alder BioPharmaceuticals
Alder BioPharmaceuticals, Inc. is a clinical-stage biopharmaceutical company committed to transforming the treatment paradigm for patients with migraine and other serious neurological or inflammatory conditions. Leveraging its pioneering monoclonal antibody technologies, Alder discovers and develops novel therapeutic antibodies designed to deliver highly differentiated, best-in-class clinical profiles. Alder’s lead pivotal-stage product candidate, eptinezumab, is being evaluated as potentially the first-to-market migraine prevention infusion therapy. Eptinezumab is a monoclonal antibody (mAb) inhibiting calcitonin gene-related peptide (CGRP), which is believed to play a key role in mediating and initiating 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; the potential BLA submission for eptinezumab; the belief that eptinezumab has the potential to advance the treatment paradigm in chronic migraine and be a meaningful treatment option; the availability of additional data from the referenced clinical trial; the belief that rapid onset of effect is a paradigm shift in migraine preventative treatment; the high unmet need for preventative migraine treatments; and the potential benefit to patients if new treatments are approved. Words such as “demonstrate,” “on track,” “potential,” “advance,” “paradigm,” “shift,” “option,” “will,” “step forward,” “about,” “plans,” “need,” 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 Alder’s development and commercialization activities; 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 Quarterly Report on Form 10-Q for the quarterly period ended September 30, 2017, which was filed with the Securities and Exchange Commission (SEC) on November 7, 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:
Ashley Cadle
TogoRun
(310) 463-0143
a.cadle@togorun.com

Investor Relations Contact:
Michael Schaffzin
Stern Investor Relations, Inc.
(212) 362-1200
michael@sternir.com                                                                                       

References

1. Day One prevalence rate comparison between eptinezumab vs. placebo
2. Baker B, Schaeffler B, Cady R, et al; Rational design of a monoclonal antibody (mAb) inhibiting calcitonin gene-related peptide, ALD403 (Eptinezumab), intended for the prevention of migraine. Poster presented at the American Academy of Neurology (AAN) 2017 Annual Meeting.
3. Migraine Research Foundation. Migraine Facts. http://www.migraineresearchfoundation.org/fact-sheet.html. Accessed June 17, 2017.
4. Lipton RB, Silberstein SD. Episodic and chronic migraine headache: breaking down barriers to optimal treatment and prevention. Headache. 2015; 55(S2):103-122.
5. Bigal ME, Krymchantowski AV, Lipton RB. Barriers to satisfactory migraine outcomes. What have we learned, where do we Stand? Headache. 2009;49(7):1028–1041.
6. Hepp, Z, Dodick DW, Varon SF, et al. Adherence to oral migraine-preventive medications among patients with chronic migraine. Cephalalgia 2015;35(6):477-88.