On this page of StockholderLetter.com we present the latest annual shareholder letter from ENANTA PHARMACEUTICALS INC — ticker symbol ENTA. Reading current and past ENTA letters to shareholders can bring important insights into the investment thesis.

 •  1/26/2026 Letter Continued (Full PDF)
 •  2/7/2023 ENTA Stockholder Letter
 •  1/26/2024 ENTA Stockholder Letter
 •  1/27/2025 ENTA Stockholder Letter
 •  More "Drugs & Pharmaceuticals" Category Stockholder Letters
 •  ENTA Benford's Law Stock Score = 95

ENTA Shareholder/Stockholder Letter Transcript:

Annual Report 2025

January 15, 2026
To Our Shareholders,
All of us at Enanta are committed to leveraging our expertise in small
molecule drug discovery to develop novel, best-in-class medicines
to transform the lives of patients with viral infections and
immunological diseases.
As we reflect on 2025, we made significant
progress across our pipeline, laying a strong
foundation. Looking to 2026, I am confident
that we are poised to achieve meaningful value
creation, and I could not be more optimistic for the
year ahead.
At the core of our efforts in virology is our
commitment to delivering the first treatment for
respiratory syncytial virus (RSV) to patients. There
is a significant unmet need for RSV treatments,
despite the availability of vaccines and prophylactic
monoclonal antibodies. Our two clinical-stage
candidates for the treatment of RSV   zelicapavir,
an N-protein inhibitor, and EDP-323, an L-protein
inhibitor   hold significant promise to advance
patient care in RSV.
In September, we reached a major milestone
by reporting data for zelicapavir, a culmination
of years of dedication and perseverance from
our team. These positive data from RSVHR, our
Phase 2b study of zelicapavir in a high-risk adult
outpatient population, represent the first time
an antiviral treatment demonstrated a clinically
meaningful benefit in high-risk adult outpatients
with RSV. Specifically, zelicapavir demonstrated
an improvement of 6.7 days in time to complete
resolution of all 13 RSV symptoms compared to
placebo, for patients with congestive heart failure,
chronic obstructive pulmonary disease or age 75
or older, termed the HR3 population. Additionally,
zelicapavir shortened time to complete resolution
of the 29-parameter total RiiQ    symptom scale
by 7.2 days in the HR3 population compared to
placebo. RSVHR also met key secondary endpoints,
including a reduction in hospitalization and antiviral
effects. We believe the totality of these data
identified multiple potential registration endpoints
for a Phase 3 trial.
We also presented new data at IDWeek    building
on previously reported positive results from the
Phase 2 study of zelicapavir in pediatric patients,
demonstrating that treatment with zelicapavir
is associated with shortened time to complete
resolution of RSV symptoms   defined as all
symptoms absent and patient discharged from
hospital. Overall, we are proud that zelicapavir has
been dosed in more than 700 people and continues
to be well-tolerated with a favorable safety profile.
Our second RSV candidate, EDP-323, has the
potential to be a best-in-disease treatment. We
presented new data at IDWeek    from the
previously disclosed successful Phase 2a human
challenge study, including a post-hoc post-exposure
prophylaxis analysis suggesting that EDP-323
may also be effective in preventing infection
after exposure. Among 68 RSV-exposed subjects
randomized to receive EDP-323 or placebo,
26% of placebo recipients became infected versus
0% of EDP-323 recipients (p<0.001). These results
are highly encouraging and support further clinical
development of EDP-323.
Looking forward, we are continuing Phase 3enabling activities, including aligning with the
U.S. Food and Drug Administration on an adult
Phase 3 trial design and on an overall pathway to
registration. In parallel, we are exploring business
development opportunities related to our RSV
program. With zelicapavir and EDP-323, we
have the leading RSV treatment portfolio in the
industry and are committed to ensuring these
drugs reach patients while maximizing value for
our shareholders.
Turning to immunology, we are focused on the
treatment of type 2 immune driven diseases, in
areas with significant unmet need. Our team is
leveraging deep expertise in medicinal chemistry
to design oral molecules that are highly potent
and selective with optimized preclinical profiles.
Currently, we are advancing programs targeting
KIT, STAT6 and MRGPRX2 inhibition.
In November, we announced EDP-978, a novel,
potent and selective oral KIT inhibitor, as our

clinical candidate for the treatment of chronic
spontaneous urticaria and potentially other mastcell-driven diseases. EDP-978 demonstrates
nanomolar potency, sub-nanomolar activity in vivo,
high selectivity for KIT versus other kinases, and
favorable in vitro and in vivo ADME properties
preclinically. We are on track to submit an
Investigational New Drug (IND) application in the
first quarter of 2026, with topline Phase 1 data
expected in the fourth quarter of 2026.
In November, we also nominated EPS-3903, a
novel, oral STAT6 inhibitor, as our lead development
candidate for the treatment of atopic dermatitis
and other diseases currently treated by dupilumab.
Preclinically, EPS-3903 exhibits nanomolar
potency and high selectivity for STAT6, with
rapid, continuous and complete (>90%) inhibition
of phosphorylated STAT6 after oral dosing in mice.
EPS-3903 also demonstrates efficacy comparable
to dupilumab in multiple disease models. Currently,
we are performing scale-up and IND enabling
activities and targeting an IND filing in the second
half of 2026.
We also expanded our immunology portfolio
with our newest program targeting MRGPRX2, a
receptor expressed predominantly on mast cells,
with the potential to address multiple chronic
inflammatory diseases including urticaria, asthma,
prurigo nodularis, migraine and others. We are
excited about this program and expect to select a
development candidate in the second half of 2026.
I   m proud of the progress we have made across
our immunology portfolio, having introduced three
new programs in just two years. With programs in
KIT, STAT6 and MRGPRX2 inhibition, we have the
potential to treat broad patient populations across
numerous diseases and to create meaningful longterm value.
Operationally, in August, we filed a suit in the
Unified Patent Court (UPC) of the European Union
against Pfizer seeking a determination of liability
for use and infringement of Enanta   s European
Patent in the manufacture, use and sale of Pfizer   s
COVID-19 antiviral, Paxlovid    (nirmatrelvir tablets;
ritonavir tablets). Under UPC procedures, a hearing
on the infringement action is expected to occur
within the UPC   s published 12-month target, with
the decision rendered within weeks thereafter,
which we understand is closely adhered to by the
UPC. By filing suit in the UPC, we will be able to
present to a panel of technical judges and seek
to obtain a judgment of liability that will apply in
the 18 European member states. In the U.S. we are
continuing to advance our appeal to the Federal
Circuit, having filed our notice of appeal in the first
quarter of 2025 and completed the briefing phase
in the first half of 2025.
Financially, we ended 2025 in a solid position
with $188.9 million in cash, cash equivalents and
marketable securities, further strengthened by
$74.5 million in gross proceeds from an upsized
public offering in October. Based on our operating
plan, we believe our existing financial resources,
including cash flows from the retained portion of
our royalties from AbbVie   s sales of MAVYRET  /
MAVIRET   (glecaprevir/pibrentasvir), will enable us
to fund our programs into fiscal 2029. MAVYRET  /
MAVIRET   (glecaprevir/pibrentasvir) remains a
leading treatment for hepatitis C virus (HCV).
Importantly, AbbVie received FDA approval of an
expanded indication for MAVYRET   in June 2025
as the first and only treatment for people with
acute HCV. This expanded indication is a heartening
reminder of the critical role this drug continues to
play in treating millions infected with HCV.
I would be remiss if I did not mention the passing of
our beloved and respected longtime Chief Financial
Officer, Paul J. Mellett, Jr. Since joining Enanta
more than two decades ago, Paul   s leadership and
generosity of spirit have been at the core of the
Company. His dedication to Enanta was complete
and steadfast as evidenced by the strength of the
team he leaves behind.
In closing, I would like to recognize the physicians,
patients and caregivers involved in our completed
RSV studies. I would also like to acknowledge our
employees for their hard work and commitment in
the past year. And finally, all of us at Enanta owe
sincere gratitude to you, our shareholders, for your
support throughout the year to execute on our
mission and to achieve our vision of transforming
the lives of patients with curative therapies. As we
look to 2026, I hope you share in our excitement
about the opportunities ahead.
Sincerely,
Jay R. Luly, Ph.D. 
President and Chief Executive Officer




 1/26/2026 Letter Continued (Full PDF)