Enanta Pharmaceuticals Reports Financial Results for its Fiscal Second Quarter Ended March 31, 2019

Webcast and Conference Call today at 4:30 p.m. ET

• Data from Phase 2a RSV program anticipated mid-2019 and Phase 2a
  NASH program by the end of third quarter of calendar 2019
• Royalty revenue for the quarter was $39.6 million
• Cash and marketable securities totaled $386.7 million at March 31,
  2019

WATERTOWN, Mass.–(BUSINESS WIRE)–Enanta Pharmaceuticals, Inc. (NASDAQ:ENTA), a research and
development-focused biotechnology company dedicated to creating small
molecule drugs for viral infections and liver diseases, today reported
financial results for its fiscal second quarter ended March 31, 2019.

“Enanta remains in a strong financial position that allows us to
continue to execute and advance our planned clinical objectives, with
important data readouts by the end of next quarter,” said Jay R. Luly,
Ph.D. President and CEO, Enanta Pharmaceuticals. “We expect to announce
three clinical milestones in the coming months − topline data from our
Phase 2a human challenge study of EDP-938 for RSV by mid-year, followed
by initiation of a Phase 1 study of EDP-514, our first HBV molecule, in
the third quarter, and then Phase 2a data from our study of EDP-305 in
NASH by the end of the third quarter.”

Fiscal Second Quarter Ended March 31, 2019 Financial Results

Total revenue for the three months ended March 31, 2019 was $39.6
million and consisted of royalty revenue derived primarily from
worldwide net sales of AbbVie’s hepatitis C virus (HCV) regimen
MAVYRET™/MAVIRET™. For the three months ended March 31, 2018, total
revenue was $44.0 million, which consisted of royalty revenue earned on
AbbVie’s global net sales of its HCV regimens. The decrease in royalty
revenue in 2019 was due to a decrease in AbbVie’s international HCV
sales quarter over quarter.

Research and development expenses totaled $34.2 million for the three
months ended March 31, 2019, compared to $21.5 million for the three
months ended March 31, 2018. The increase in research and development
expenses was primarily due to increased preclinical and clinical costs
associated with the progression of Enanta’s wholly-owned R&D programs in
respiratory syncytial virus (RSV), non-alcoholic steatohepatitis (NASH)
and primary biliary cholangitis (PBC), as well as preclinical efforts in
hepatitis B virus (HBV) preparing EDP-514 for an initial clinical trial.

General and administrative expenses totaled $6.8 million for the three
months ended March 31, 2019, compared to $5.7 million for the three
months ended March 31, 2018. The increase in general and administrative
expenses was primarily due to increases in compensation expense driven
by increased headcount.

Enanta recorded an income tax benefit of $3.2 million for the three
months ended March 31, 2019 compared to income tax expense of $5.4
million for the same period in 2018. Despite reporting pre-tax income,
Enanta recorded an income tax benefit during the quarter due to tax
deductions from employee stock award-related activity during the
quarter. Enanta’s effective tax rate for the six months ended March 31,
2019 was approximately 2% and differs from the federal statutory rate of
21% due to federal research and development tax credits and tax
deductions from employee stock award-related activity.

Net income for the three months ended March 31, 2019 was $4.1 million,
or $0.20 per diluted common share, compared to net income of $12.6
million, or $0.61 per diluted common share, for the corresponding period
in 2018.

Enanta’s cash, cash equivalents and short-term and long-term marketable
securities totaled $386.7 million at March 31, 2019. This compares to a
total of $325.1 million at September 30, 2018. Enanta expects that its
current cash, cash equivalents and marketable securities, as well as its
continuing royalty revenue, will be sufficient to meet the anticipated
cash requirements of its existing business and development programs for
the foreseeable future.

Development Programs and Business Review

EDP-938, N-Protein Inhibitor for Respiratory Syncytial Virus (RSV):

• As announced in March, enrollment is complete in the Phase 2a human
  challenge study of EDP-938 in RSV. This study is a randomized,
  double-blind, placebo-controlled study in healthy adult subjects
  randomized into 1 of 2 dosing arms or a placebo arm. Topline data is
  expected mid-calendar 2019.
• Assuming the Phase 2a challenge study data are positive, our goal is
  to initiate a Phase 2b study by the end of calendar 2019 in adult
  outpatients with RSV infections.

EDP-305, FXR Agonist for Non-Alcoholic Steatohepatitis (NASH):

• As announced in March, enrollment is complete in the ARGON-1 study in
  NASH. ARGON-1 is a 12-week, randomized, double-blind,
  placebo-controlled Phase 2a study evaluating the safety, tolerability,
  pharmacokinetics and efficacy of EDP-305 in subjects with NASH.
  Topline data is expected by the end of the third quarter of calendar
  2019.
• Enanta also expects to identify a follow-on FXR clinical candidate in
  calendar 2019.

EDP-514, Core Inhibitor for Hepatitis B Virus (HBV):

• New preclinical data was presented in a poster at the International
  Liver Congress™ 2019, (ILC) in Vienna, Austria in April. Data in this
  poster demonstrate that EDP-514, a novel class II HBV core inhibitor,
  is a potent inhibitor of HBV replication, and prevents the de novo
  formation of new cccDNA in primary human hepatocytes when given early
  during infection. Data also show that EDP-514 is pan-genotypic, and
  that combinations of EDP-514 with nucleoside reverse-transcriptase
  inhibitors (NRTIs − the current anti-viral therapies for HBV) or a
  class I core inhibitor, result in additive to synergistic antiviral
  effects in vitro. ln vivo, EDP-514 demonstrates
  excellent efficacy with >4-log viral load reduction in HBV-infected
  PXB mice.
• A Phase 1 study of EDP-514 is expected to begin in the third calendar
  quarter of 2019. The study will evaluate single and multiple doses of
  EDP-514 in healthy volunteers and will incorporate a Phase 1b arm in
  patients with chronic HBV infection.

Upcoming Events and Presentations

• May 22, 2019 – RBC Capital Markets Healthcare Conference, New York
• June 18-19, 2019 – Raymond James Life Science and MedTech Conference,
  New York
• June 19-20, 2019 – JMP Securities Life Sciences Conference, New York
• Enanta plans to issue its fiscal third quarter financial results press
  release, and hold a conference call regarding those results, on August
  6, 2019.

Conference Call and Webcast Information
Enanta will host a
conference call and webcast today at 4:30 p.m. ET. To participate in the
live conference call, please dial (855) 840-0595 in the U.S. or (518)
444-4814 for international callers. A replay of the conference call will
be available starting at approximately 7:30 p.m. ET on May 7, 2019,
through 11:59 p.m. ET on May 8, 2019 by dialing (855) 859-2056 from the
U.S. or (404) 537-3406 for international callers. The passcode for both
the live call and the replay is 1191209. A live audio webcast of the
call and replay can be accessed by visiting the “Events and
Presentation” section on the “Investors” page of Enanta’s website at www.enanta.com.

About Enanta Pharmaceuticals, Inc.
Enanta Pharmaceuticals is
using its robust, chemistry-driven approach and drug discovery
capabilities to become a leader in the discovery and development of
small molecule drugs for the treatment of viral infections and liver
diseases. Enanta’s research and development efforts are currently
focused on the following disease targets: respiratory syncytial virus
(RSV), non-alcoholic steatohepatitis (NASH)/ primary biliary cholangitis
(PBC), and hepatitis B virus (HBV).

Enanta’s research and development activities are funded by royalties
from HCV products developed under its collaboration with AbbVie.
Glecaprevir, a protease inhibitor discovered by Enanta, is now sold by
AbbVie in numerous countries as part of its newest treatment for chronic
hepatitis C virus (HCV) infection. This leading HCV regimen is sold
under the tradenames MAVYRET™ (U.S.) and MAVIRET™ (ex-U.S.)
(glecaprevir/pibrentasvir). Please visit www.enanta.com
for more information.

FORWARD LOOKING STATEMENTS
This press release contains
forward-looking statements, including statements with respect to the
prospects for advancement of Enanta’s clinical programs in RSV and
NASH/PBC and its preclinical program in HBV, as well as the prospects
for future royalty revenue to Enanta from sales of AbbVie’s
MAVYRET™/MAVIRET™ regimen for HCV. Statements that are not historical
facts are based on management’s current expectations, estimates,
forecasts and projections about Enanta’s business and the industry in
which it operates and management’s beliefs and assumptions. The
statements contained in this release are not guarantees of future
performance and involve certain risks, uncertainties and assumptions,
which are difficult to predict. Therefore, actual outcomes and results
may differ materially from what is expressed in such forward-looking
statements. Important factors and risks that may affect actual results
include: Enanta’s revenues in the short-term are dependent upon the
continued success of AbbVie’s commercialization of its MAVYRET™/MAVIRET™
HCV regimen; the impact of development, regulatory and marketing efforts
of others with respect to competitive treatments for RSV, NASH, PBC and
HBV; competitive pricing, market acceptance and reimbursement rate
actions affecting MAVYRET™/MAVIRET™ compared to competitive HCV products
on the market; the discovery and development risks of Enanta’s programs
in RSV, NASH, PBC, and HBV; the competitive impact of development,
regulatory and marketing efforts of others in those disease areas;
Enanta’s lack of clinical development experience; Enanta’s need to
attract and retain senior management and key research and development
personnel; Enanta’s need to obtain and maintain patent protection for
its product candidates and avoid potential infringement of the
intellectual property rights of others; and other risk factors described
or referred to in “Risk Factors” in Enanta’s most recent Form 10-Q for
the quarter ended December 31, 2018, and other periodic reports filed
more recently with the Securities and Exchange Commission. Enanta
cautions investors not to place undue reliance on the forward-looking
statements contained in this release. These statements speak only as of
the date of this release, and Enanta undertakes no obligation to update
or revise these statements, except as may be required by law.

Contacts

Investor Contact:
Carol Miceli
617-607-0710
[email protected]

Media
Contact:
Kari Watson
MacDougall Biomedical Communications
781-235-3060
[email protected]