Second Quarter 2016Earnings Call

August 9, 2016

Forward-Looking Statements

All of the statements in this presentation that are not statements of historicalfacts constitute forward-looking statements within the meaning of the PrivateSecurities Litigation Reform Act of 1995. Examples of such statements includefuture product development and regulatory events and goals, anticipatedclinical trial results and strategies, product collaborations, our businessintentions and financial estimates and results. These statements are basedupon management’s current plans and expectations and are subject to anumber of risks and uncertainties which could cause actual results to differmaterially from such statements. A discussion of the risks and uncertaintiesthat can affect these statements is set forth in the Company’s annual andquarterly reports filed from time to time with the Securities and ExchangeCommission under the heading “Risk Factors.” The Company disclaims anyintention or obligation to revise or update any forward-looking statements,whether as a result of new information, future events, or otherwise.

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Two-Pillar Strategy For Growth

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ENHANZE™ Platform PEGPH201 Platform

nCH2 CH2 OCH2 O

CH3

N

H

OCH2 CH2 OO CH2

CH3

NH

O

n

CH2 CH2 OO CH2CH3

N

O H

n

nCH2 CH2 OCH2 O

CH3

N

H

OCH2 CH2 OO CH2

CH3

N

O H

n

PEGylated form of rHuPH20

Licensing/Royalty Agreements Based On Proprietary Enzyme, rHuPH20

Investigational New Oncology DrugStudying Pan-tumor Potential

1) PEGPH20 is an investigational new drug. Safety and efficacy profiles have not been established and it is not currently available forcommercial distribution.

PEGPH20 Goal: Improve Targeting Of Co-Administered Cancer Therapies

3

4

HALO 202 | Pancreatic: Stage 1 PFS ResultsWith Ventana Companion Diagnostic

Bullock, et. al. “Final Analysis of Stage 1 Data" American Society of Clinical Oncology (ASCO) Annual Meeting 2016.

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HALO-301|Pancreatic: Enrollment Ongoing

• Randomized (2:1 PAG:AG), double-blind, placebo-controlled, global

• First patient dosed in March 2016, approximately 200 sites in 20 countries

• Interim analysis when target number of PFS events reached

• PFS powered with a hazard ratio of 0.59 (to detect a 41% risk reduction for progression)

PEGPH20 + ABRAXANE® + gemcitabine (PAG)

ABRAXANE® + gemcitabine (AG) + placebo

MetastaticPDA

High-HA patients

N=420

Primary Endpoints: Progression-Free Survival (PFS)Overall Survival (OS)

Studying Pan-Tumor Potential of PEGPH20

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PEGPH20 TrialsPreclinical Phase 1 Phase 2 Phase 3

In CombinationWith Tumor

Gemcitabine and nab-Paclitaxel (Abraxane®)

Pancreatic Cancer

Pembrolizumab (Keytruda®)

Gastric Cancer / NSCLC

Eribulin (Halaven®)with Eisai

BreastCancer

• PRIMAL study in NSCLC discontinued in August 2016. Data to be presented at a scientific forum within 12 months.

• Additional Investigator Sponsored Trials in Pancreatic Cancer: SWOG, UCSF.

Oncology Pipeline Update

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PEG-ADA2 Immune Checkpoint Inhibitor

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>100x IncreaseTumor Microenvironment Adenosine

~0.1 µM → ~50 µM

ATP

ATPAdenosineAMP

Tumor

CD73CD39

Adapted from Stagg & Smyth, Oncogene, 2010

• Abnormally high levels accumulate in the tumor microenvironment

• Binds to receptor checkpoints on immune cells• Contributes to an immunosuppressive tumor

microenvironment

Adenosine: Attractive immune checkpoint target

• Improved pharmacokinetics and enzyme activity• Anti-tumor responses observed in several animal

models− Increase in T-cell infiltration− Decrease in high adenosine levels in tumor

microenvironment

PEG-ADA2: Engineered human enzyme targeting adenosine

HTI-1511 Anti-EGFR Antibody Drug Conjugate

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Released Cytotoxins

Internalized ADC

ADC

ADC overcomesmutation resistance and selectively kills tumor cell

KRASMut

BRAF

MEK

ERK/MAPK

Tumor Cell Death

ADC = antibody-drug conjugate

Adapted from Pao, Nature Reviews Cancer 10, 760-774 (2010)

• Engineered monoclonal antibody with attenuated binding to human skin grafts

• ADC mechanism targets KRAS- or BRAF-mutated tumors in mice

• Utilization of next generation, Thiobridge chemistry

• Safety profile met criteria for candidate nomination

• Complete tumor responses observed in PDx tumor models

• IND enabling studies underway

HTI-1511: Anti-EGFR Antibody Drug Conjugate

ENHANZE™ Technology

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ENHANZE: Our Novel Delivery Platform

Potential Benefits:• Facilitate transition of IV therapies to

subcutaneous administration• Reduce multiple injections• Enable large volume of biologics to

be delivered subcutaneously• Reduce time required for drug

administration• Life cycle management, including

potential patent life extension

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Partner Target US /OUS Preclinical Phase 1 Phase 2/3 Approved

Herceptin SC OUS

Mabthera SC OUS

Perjeta SC --

HYQVIA US

HYQVIA1 OUS

Daratumumab --

Rivipansel --

Bococizumab --

Humira --

3 Targets Identified --

ENHANZE: Our Novel Delivery Platform

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Phase 1 Complete

1) HYQVIA approved for primary immunodeficiencies; also currently in Phase 3 study for chronic inflammatory demyelinating polyneuropathy (CIDP).

ENHANZE Momentum: Partnerships Accelerating, Royalty Pipeline Building

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$25M

$160M

5

$23M

$130M

9

$15M

$113M

5

$8M

$85M

6

$10M

$37M

1

$20M

$37-47M

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Upfront

Milestones/ Target

Targets

• Time from deal signing to clinic accelerating• 4 active Phase 1 Studies underway in new products• Phase 3 Study ongoing for HYQVIA CIDP indication• Phase 1 Study recently completed with Pfizer’s Rivipansel

20152007 2012 20142006

Mid-single Digit Royalties on Net Sales

Roche Update: SC Conversion Rates1

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1) Information provided during Roche investor update (Jul. 21, 2016).

Financial Update

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2Q 2016 2Q 2015 % Change

Total Revenue $33.3 $43.4 (23%)

Royalty Revenue $12.3 $6.4 92%

Bulk rHuPH20 Sales $9.5 $8.2 16%

Hylenex® Recombinant $4.2 $4.2 0%

Collaboration Revenue2 $7.4 $24.7 (70%)

Second Quarter 2016 Financial Highlights1

$ U.S. in Millions (unaudited)

1) Dollar amounts and percentages, as presented, are rounded.2) 2Q 2015 Collaboration Revenue includes a $23M upfront payment from AbbVie.

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2Q 2016 2Q 2015 % Change

Total Revenue $33.3 $43.4 (23%)

Total Operating Expense $55.1 $39.2 41%

Cost of Product Sales $8.3 $8.1 2%

R&D Expense $35.5 $21.2 68%

SG&A Expense $11.2 $9.8 14%

Net Income / (Loss) ($26.9) $3.0 --

EPS ($0.21) $0.02 --

Cash and marketable securities $230.0 $140.7 --

Second Quarter 2016 Financial Highlights1

$ U.S. in Millions, except EPS (unaudited)

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1) Dollar amounts and percentages, as presented, are rounded.

2016 Financial Guidance

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Previous Updated August 2016

Revenue $130M to $145M $140M to $150M

Operating Expenses $245M to $260M $245M to $260M

Cash Flow $45M to $65M $65M to $85M

Year-end Cash1 $170M to $190M $170M to $190M

1) Year-end cash guidance was increased from Q1 2016 guidance range on Jun. 8, 2016.

Value Enhancing Milestones Throughout 2016

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Goal Target Date

Initiate HALO-301|Pancreatic trial Complete

Initiate HALO-Eisai Study in Breast Cancer Patients Complete

Advance to Dose Expansion Phase in KEYTRUDA Study Q4 2016

Project reporting mature data from HALO 202 | Pancreatic Q4 2016

Seek new ENHANZE collaboration and licensing agreements and support current partner clinical progress

2016

✓

✓

Second Quarter 2016Earnings Call

August 9, 2016