Corporate PresentationJefferies 2015 Global Healthcare Conference

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Special Note Regarding Forward-Looking StatementsThis presentation contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements contained in this presentation that do not relate to matters of historical fact should be considered forward-looking statements, including without limitation statements with respect to expectations regarding the timing of discussions with the FDA and/or USDA and approval and licensure of products; development programs, clinical trials and studies, including without limitation the timing of full enrollment in and the announcement of results of such trials and studies; commercialization and manufacturing of products, including without limitation establishing larger manufacturing capacities for AT-004 and AT-005; the sufficiency of financial resources; expected future cash balance and liquidity; licensing initiatives and collaborations; the Company’s plans and opportunities, including without limitation offering a unique portfolio of innovative therapeutics; and the Company’s belief that its products and product candidates will result in improved outcomes for pets.

These forward-looking statements are based on management’s current expectations. These statements are neither promises nor guarantees, but involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements, including, but not limited to, the following: our limited operating history and expectations of losses for the foreseeable future; our lack of commercial sales; our failure to obtain any necessary additional financing; market conditions and our ability to raise capital under the shelf registration statement from the sale of our securities; our substantial dependence on the success of certain of our lead product candidates; our dependence on novel technologies and compliance with complex regulatory requirements; our inability to obtain regulatory approval for our existing or future product candidates; the lack of commercial success of our current or future product candidates; our inability to realize all of the anticipated benefits of our acquisitions of Vet Therapeutics and Okapi Sciences; uncertainties regarding the outcomes of studies regarding our products; the uncertainty of outcomes of the development of pet therapeutics, which is a lengthy and expensive process; effects of competition; our inability to identify, license, develop and commercialize additional product candidates; our failure to attract and keep senior management and key scientific personnel; our reliance on third-party manufacturers, suppliers, partners and other third parties which conduct our target animal studies and certain other development efforts; unanticipated difficulties or challenges in the relatively new field of biologics development and manufacturing; our ability to market our products only for the treatment of indications for which they are approved; our small commercial organization; difficulties managing the growth of our organization; our significant costs of operating as a public company; risks related to the restatement of our financial statements for the year ended December 31, 2013 and the identification of a material weakness in our internal control over financial reporting; changes in distribution channels for pet therapeutics; consolidation of our customers; limitations on our ability to use our net operating carryforwards; impact of generic products; unanticipated safety or efficacy concerns; our limited patents and patent rights; our failure to comply with our intellectual property license obligations; our infringement of third party patents and challenges to our patents or rights; litigation resulting from the misuse of our confidential information; the uncertainty of the regulatory approval process; our failure to comply with regulatory requirements or obtain foreign regulatory approvals; our failure to report adverse medical events related to our products; legislative or regulatory changes; the volatility of our stock price; our status as an “emerging growth company,” as defined in the JOBS Act; the potential for dilution if we sell shares of our common stock in future financings; the significant control over our business by our principal stockholders and management; the potential that a significant portion of our total outstanding shares could be sold into the market in the near future; effects of anti-takeover provisions in our charter documents and under Delaware law; and our intention not to pay dividends. These and other important factors discussed under the caption "Risk Factors" in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission, or SEC, on March 16, 2015, along with our other reports filed with the SEC, could cause actual results to differ materially from those indicated by the forward-looking statements made in this presentation. Any such forward-looking statements represent management's estimates as of the date of this presentation. While we may elect to update such forward-looking statements at some point in the future, we disclaim any obligation to do so, even if subsequent events cause our views to change. These forward-looking statements should not be relied upon as representing our views as of any date subsequent to the date of this presentation.

Safe Harbor Statement

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Investment Highlights

Large, growing market

De-risked drug development

Private-pay

Portfolio approach

Scalable and capital-efficient

First mover, pure-play

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Defining Pet Therapeutics

2010 2013 2014

Founded

Completed IPO 3 products in development

Portfolio Expansion: Option Deals Vet Therapeutics Okapi Sciences Advaxis Vet-Stem Atopix

Over 18 products in development

Introduction of Lymphoma MAb

2015 2016

Regain Rights to AT-004

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Source: APPA.

Our Market

Large and growing

– 2014 U.S. pet spend of $58B

Insensitive to recent recessions

68% of U.S. households

– 96M cats

– 83M dogs

Medicalization drives growth

– Historically, limited innovation

– Pet therapeutics underrepresented

U.S. Pet Owners Spend($Billions)

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The Evolution of Pet Ownership

“Snoopy Generation” “Brian Generation”

Pets are family whose medical needs merit quality care

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A Favorable Comparison

Multiple Species Steps Direct to Species

~$1.3B ~$10M

~10 Years ~5 Years

Third Party Payer Private Pay

Generic Pressure Innovator Brand Loyalty

Difficult & Indirect Accessible & Direct

PetsHumans

De

velo

pm

ent

Co

mm

erc

ial

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Building the Portfolio

Toxicology data are available

Manufacturing is scaled-up

Effectiveness data are available

Key Attributes

Unmet medical need

High incidence or prevalence

Known mechanism of action

Nuance in science

“Early de-risking”

Early De-Risking

Leveraging the investment in human therapeutics Pharmaceuticals Biologics US and OUS

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FDA and USDA TimelinesFDA Center for Veterinary Medicine

Proof of Concept

INAD

Chemistry, Mfg. & Controls (CMC)

Safety

Effectiveness

Labeling, FOI Summary, Other

Administrative NADA

Year 5Year 1 Year 2 Year 3 Year 4

USDA - Center for Veterinary Biologics

Proof of Concept

Manufacturing

File for Product License

Preclinical

Field Safety and Efficacy

Conditional Product License*

Extended Field Safety and Efficacy Study

Full Product License* Conditional l i censes granted under specia l ci rcumstances

Year 5Year 1 Year 2 Year 3 Year 4

Pilot ---> Pivotal

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Our Pipeline

PilotPivotal/

CommercialProof ofConcept

AT-004Monoclonal Antibody

B-cell Lymphoma

AT-005Monoclonal Antibody

T-cell Lymphoma

AT-001(grapiprant)

Osteoarthritis

AT-002(capromorelin)

Appetite Stimulant

AT-014Osteosarcoma

AT-003(bupivacaine liposome injectable suspension)

Post-operative Pain

AT-012Feline Calicivirus

AT-009Mast Cell Tumor

AT-011Canine Parvovirus

AT-010Atopic Dermatitis

AT-015Lymphoma

AT-017Lymphoma

AT-BetaEpilepsy

AT-008Lymphoma

AT-018Atopic Dermatitis

AT-002(capromorelin)

Weight Gain

AT-002(capromorelin)

Weight Gain

AT-007Feline Immunodeficiency Virus

AT-001(grapiprant)

Degenerative Joint Disease

AT-006Feline Herpesvirus

AT-016Allogeneic Stem Cell OA

AT-003(bupivacaine liposome injectable suspension)

Post-operative Pain

AT-IotaPeriodontal

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Our Industry

Total number of NADAs NADAs for dogs / cats Pet therapeutic NCEs*

2011 12 6 2

2012 11 6 0

2013 6 4 2

2014 11 4 0

* NCE defined as new chemical entity not previously approved in humans or animals (excluding parasite drugs).

Non-confidential materials

(may not be comprehensive)

~15 ~3

~1

~2

~1

Products at Field Study Stage in Dogs and Cats

Historic Productivity of the Animal Health Industry

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Industry Recognition

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Annual Exams17%

Diagnostics17%

Surgery17%Non-Invasive

Procedures9%

Pet Food Sales4%

Heartworm Product Sales

6%

Flea-Tick Product Sales

6%

Vaccinations15%

Source: DVM Newsmagazine’s State of the Profession Report 2012.

Innovation is valued and desired

Medicines are high margin to practice

Facing pressure from alternative channels

Other Pharma 9%

Practice Revenue Mix

Commercial EnvironmentAlignment with the Veterinarian

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Therapeutic Clusters

Oncology/Specialty Pain/Primary Care

AT-016Allogeneic Stem Cell

AT-003Post-operative Pain

AT-007Immunodeficiency Virus

AT-001Osteoarthritis

AT-006Herpesvirus

AT-004B-cell Lymphoma

AT-005T-cell Lymphoma

AT-002Appetite Stimulant

AT-014Osteosarcoma

AT-018Atopic Dermatitis

AT-012Feline Calicivirus

AT-009Mast Cell Tumor

AT-010Atopic Dermatitis

AT-EpsilonMelanoma

AT-ZetaHemangiosarcoma

AT-015Cat Lymphoma

AT-BetaEpilepsy

AT-011Parvo Virus

AT-017Lymphoma

AT-EtaAnti HER-2 MAb

AT-IotaPeriodontal

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OncologistsInitial customer

Board Certified Veterinary Oncologists

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OncologyTarget-rich, known biology

Chemotherapy Human Cancer Use Pet Cancer Use

Cyclophosphamide Lymphomas MM, solid tumors

Doxorubicin Lymphomas MM, solid tumors

Vincristine Lymphomas MM, solid tumors

Prednisone Lymphomas MM, solid tumors

L-asparaginase Leukemia, Lymphoma

Carboplatin Solid Tumors

Cis-platinum Sarcoma, Carcinoma, Lymphoma

Mitoxantrone Breast cancer, AML, Lymphomas

Lomustine Brain/CNS, Lymphoma, Mast cell

Methotrexate Lymphomas Osteosarcoma

Antibody Human Cancer Use Pet Cancer Use

Rituxan (CD20) Non-Hodgkin's Lymphoma

Avastin (VEGF) Solid Tumors X

Erbitux (EGFR) Solid Tumors X

Herceptin (HER2) Breast Cancer X

Campath (CD52) Chronic Lymphocytic Leukemia

Mylotarg (CD33) Acute Myeloid Leukemia X

Zevalin (CD20) Follicular Lymphoma X

Bexxar (CD20) Non-Hodgkin's Lymphoma X

Vectibix (EGFR) Solid Tumors X

TheraCIM (EGFR) Solid Tumors X

Human Chemo Market

Human Cancer Antibody Market

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Pet AntibodiesA proprietary platform

Pet specific antibodies

Pet Fc region

Most effective IgG sequence

Straightforward engineering with no shuffling

IP position directed at platform

Mouse Pet Specific

Highly specific‒ Developed against pet targets

Non immunogenic‒ Compatible with immune system

Highly potent‒ Engages immune system

Cost effective‒ High yield production

heavy chain

light chain

VH

VL CH1

CH2

CH3

CL

Proprietary Platform Pet Specific Antibody Ideal Profile

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Oncology MarketSpecialty approach

4Q14 1H15 2H15 2H161H16

Veterinary Cancer Society

T-Cell MAb Full License

T-CHOMP and T-LAB Studies

T-CEP Experience Program

~ Three dozen Participating

Practices

~75 Participating

Practices

Additional Oncology Practices

B-Cell Studies

Veterinary Cancer Society

T-CHOMP/T-LAB Results

Scientific Studies

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Pain MarketMultimodal management

Disease Progression

Osteoarthritis

Over the counter Coxib NSAIDs EP4 MAbs, Capsaicin

Regenerative /Disease modifying

Pre / Post Surgical

Anesthesia Fentanyl Bupivacaine Bupenorphrine

Cancer

Opioids Intrathecal

Neuropathic and Other

Human drugs used off label

Acupuncture

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American College of Veterinary Internal MedicineJune 3-6 Schedule of Events

The Evolving Science of Immunotherapeutics in Veterinary Oncology A Prospective, Open-Label Study Evaluating Treatment of Canine B-cell Lymphoma with L-Asparaginase,

Doxorubicin, and a Canine Anti-CD20 Monoclonal Antibody Clinical Application of Immunotherapeutics in Veterinary Oncology Anti-CD20 Monoclonal Antibody Canine Lymphoma Therapy: A Double-Blind, Randomized, Placebo-

Controlled Study Combination Listeria-Based Immunotherapy Plus Palliative Radiation Delays Tumor Progression and

Prolongs Overall Survival in Canine Osteosarcoma

Cancer therapies

Safety of the Ghrelin Agonist, Capromorelin, Administered Daily to Beagle Dogs for One Year Capromorelin, An Orally Active Ghrelin Agonist Caused Sustained Increases in IGF-1, Increased Food Intake

and Body Weight in Cats Safety of the Ghrelin Agonist, Capromorelin Administered Daily to Cats for 91 Days at an Oral Dose of

6mg/kg New Therapeutic Advances in Inappetence for Pets

Inappetence

Introduction to the Emerging Piprant Therapeutic Class of Prostanoid Receptor Antagonists Safety and Toxicokinetic Profiles in Cats Administered Grapiprant, A Selective Prostaglandin-Receptor

Antagonist

Pain Management

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Anticipated Upcoming Events

2015 ACVIM Forum (multiple abstracts and scientific presentations)

Results of AT-002 Dog US pivotal field effectiveness study

Results of AT-003 Dog US pivotal field effectiveness study

Results of pilot studies (AT-016 Dog, AT-003 Cat, AT-002 Cat, AT-003 Cat)

Initiation of pilot studies (AT-017, AT-018)

Continued AT-004/AT-005 availability

Full USDA license for AT-005

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Our Financial Profile

March 31, 2015 cash balance $87.4M

Net Loss for 1st Quarter ending March 31, 2015 was ($8.8M) or ($0.26)/ share

R&D investment will increase as a result of advancing pipeline

Continue to identify non-dilutive sources of capital‒ Partnering opportunities globally

‒ Out-licensing of non-core products

‒ Debt instruments

Strong and supportive investor base

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Investment Highlights

Portfolio approach

Scalable and capital-efficient

First mover, pure-play

Large, growing market

De-risked drug development

Private-pay

Product Detail

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AT-001 (grapiprant)For osteoarthritis pain

Medical Need

Established market (U.S. sales $260M, mostly NSAIDs for dogs)

Existing NSAID products have side effects and require monitoring

Better tolerated product for pain and inflammation of osteoarthritis

Our Solution

EP4 Prostaglandin Receptor Antagonist

‒ Potential for significantly improved tolerability profile vs. Coxibs

Positive results from pivotal field effectiveness study in December 2014

Technical section complete for safety received; CMC submitted

FDA approval anticipated in 2016

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AT-001 (grapiprant)EP4 receptor biology

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AT-002 (capromorelin)For inappetence

Medical Need

No currently approved product

Effective appetite stimulus to avoid feeding tubes and euthanasia

Seen in aging and chronic conditions

Our Solution

Mimics ghrelin (hunger hormone) to turn on appetite

Statistically significant results on increased appetite and weight gain in dog pilot study

Pivotal field study results expected in late-June 2015

Technical section complete for safety received; CMC submitted

FDA approval anticipated in 2016

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AT-002 (capromorelin)Ghrelin biology

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AT-003 (ER bupivacaine)For post-operative pain

Medical Need

Pain increasingly recognized and treated

Need for long-acting, non-narcotic post-operative pain relief

Our Solution

Bupivacaine liposome injectable suspension

Pacira launched product for human use in early 2012

Announced positive results from pilot field study in 3Q 2014

Pivotal field study results expected in July 2015

Technical section complete for safety received; CMC submitted

FDA approval anticipated in 2016

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AT-003 (ER bupivacaine)

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Canine LymphomaIdeal for first antibody therapy

A canine-specific antibody therapy could achieve in dogs what Rituxan has done for human lymphoma

Lymphoma is most common blood cancer in dogs

- 8% of total dog cancer

Lymphoma is the most treated cancer

- Chemotherapy is the current “standard of care”

- Treatment cost ranges between $2,500 and $10,000

Clinical manifestations are similar to humans

Lymphocyte targeting has proven efficacious in pets

HemangiosarcomaSarcoma

Lymphoma

Mast Cell

Skin

BoneOther

RITUXAN-LIKE APPROACH

Incidence

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AT-004 and AT-005 Lymphoma monoclonal antibodies

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Medical Need

76% of all lymphoma is B-cell lymphoma

Chemo achieves short remissions and has a very high relapse rate

Chemo can be harsh on pets and burdensome on owners

Need effective and safe therapy to maintain remission as long as possible

Our Solution

First-in-class product

Aid in the treatment of canine B-cell lymphoma

USDA full license granted

Planning additional scientific studies and clinical studies under field conditions in combination with chemotherapy

Second generation product with increased specificity and ability to access the OUS markets

AT-004Canine-specific antibody for B-cell lymphoma

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Human ExperienceMAbs are now standard of care

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A-004 for B-Cell LymphomaProgression Free Survival for Phase 1 - Updated on 26Mar14

Surv

ival D

istr

ibution F

unction

0.00

0.25

0.50

0.75

1.00

pfs1

0 100 200 300 400 500 600

STRATA: treat=Mab Censored treat=Mab treat=Placebo

------ : Placebo arm: MAb arm

Days

Pro

gres

sio

n F

ree

Surv

ival

Dogs treated with anti-CD20 MAb + CHOP (1 cycle) had statistically significant longer median PFS times than those treated with CHOP (1 cycle) alone

G.K. Ogilvie, D.R. Proulx, L. VanHorn, et al. Treatment of Canine B-Cell Lymphoma with Chemotherapy and a Canine Anti-CD20 Monoclonal Antibody: A Prospective Double-Blind, Randomized, Placebo-Controlled Study. Abstract presented at VCS 2014 Conference, St. Louis, MO.

p<0.0001

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Medical Need

24% of all lymphoma is T-cell lymphoma

T-cell lymphoma is more aggressive and less responsive to treatment

Our Solution

First-in-class product

Aid in the treatment of canine T-cell lymphoma

Submitted for USDA product license; conditional license received in January 2014

Initiated T-CHOMP, T-LAB and T-CEP studies under field conditions in combination with chemotherapy

Additional scientific studies

AT-005Canine-specific antibody for T-cell lymphoma

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AT-014Therapeutic vaccine for osteosarcoma

Medical Need

Estimated 8,000 to 20,000 dogs in US are affected annually

Standard of care is amputation and post-operative chemotherapy

Nine-to-twelve months median survival; only 25% of dogs survive two years

Need for effective and safe therapy with longer survival time

Our Solution

First-in-class product to aid in the treatment of osteosarcoma

Developed at University of Pennsylvania by Advaxis

Statistically significant survival post amputation

Filed for USDA approval conditional license

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AT-014Biology

Live Vector Accesses Antigen Presenting Cells

TAA-Fusion Peptide Secreted

Triggers Innate and Adaptive Pathogen Immune Response

Tumors Now “Seen” As Pathogen-Infected and Targeted By T-Cells

Lm-LLO Immunotherapy Infusion

MHC

II

MHC

I

CD4+ T

Cell

CD8+ T

Cell

LLO mediated

escape

Activated

Dendritic Cell

tLLO-TAA Fusion

Proteins

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Medical Need

Incidence in dogs estimated at up to 10% with recent product launch peak sales estimated at $200M

Chronic condition which often can onset at a young age (1-3 years old)

Owners can easily diagnose symptoms including itching, sneezing, hair loss, paw licking, stains on skin etc.

Our Solution

CRTH2 mechanism treats underlying disease rather than symptoms

Target has been validated in human medicine (asthma, allergic rhinitis and others)

AT-018Atopic Dermatitis

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AT-018Role of Th2 Cellular Immunity

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De-risking StrategiesDose-finding and pilot studies pivotal study

AT-001 (Grapiprant) An oral, once-daily EP4 receptor antagonist

Pilot field study completed in 2013

Clinical success rates based on the validated CBPI at day 28 were 48.1% for the once-daily dose of AT-001 vs. 31.3% for the placebo group which represents a statistically significant difference (p<0.05)

The Pain Severity Score and the Pain Interference Score both improved significantly on day 28 (p<0.01)

The clinical success rates on days 7, 14 and 21 vs. placebo group were all statistically significant (p<0.05)

In January 2015, Aratana received the target animal safety technical section complete letter for AT-001 in dogs from the CVM

Anticipate approval in 2016

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AT-003 (ER Bupivacaine) Post-operative pain Multi-site, placebo-controlled study

in 46 dogs in an orthopedic indication

Better pain control for up to 72 hours based on pain score and time-to-rescue (p<0.05)

In January 2015, Aratana received the target animal safety technical section complete letter for AT-003 in dogs from the CVM

Dog pivotal field effectiveness study complete (protocol concurrence)

Top line results 2H July 2015

De-risking StrategiesDose-finding and pilot studies pivotal study

AT-002 (Capromorelin) Ghrelin agonist for appetite and

weight gain

Multi-site, pilot field study in dogs (17 treated, 12 placebo)

Appetite score on Day 6: 79 vs. 22 placebo (p=0.025); Body weight 3.2% vs. -0.5% placebo (p=0.024)

Dog pivotal field effectiveness study complete (protocol concurrence)

Top line results late June 2015

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AT-005 (T-cell Lymphoma) Monoclonal antibody to aid in the

treatment of canine T-cell lymphoma

Medical science liaisons rather than general sales strategy

Targeting specialist oncologists

T-CHOMP, T-LAB and T-CEP experience studies to better understand the market and how the product will be used

T-Chomp enrollment completed

Anticipating full license from the USDA in 2015

AT-014 (Cancer Vaccine) Canine osteosarcoma

Study in 18 client-owned dogs

MST not yet reached for treated group; 80% of dogs surpassing the MST of the control group (p<0.001) and 60% still alive

USDA accepted the efficacy data to support conditional licensure

Transferring manufacturing to USDA-licensed manufacturer

Anticipate receipt of conditional USDA license in 2016

De-risking StrategiesRegulatory and post-marketing studies

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Other Pipeline ProductsProduct Species Indication Development Status

AT-006 Cat Herpesvirus Designing pivotal study with partner

AT-007 Cat Immunodeficiency virus Pilot studies

AT-008 Dog Lymphoma Planning for pivotal studies in Europe

AT-009 Dog Mast cell tumor Lead selection

AT-010 Dog Atopic dermatitis Lead selection

AT-011 Dog Parvovirus Lead selection

AT-012 Cat Calicivirus Lead selection

AT-015 Cat Lymphoma Proof of concept

AT-016 Dog Osteoarthritis Pilot studies

AT-017 Dog Lymphoma Lead selection