First Quarter 2016Earnings Call

May 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.

1

Our FocusTo discover, develop and commercialize

biopharmaceuticals that target the extracellular matrix and tumor

microenvironment

2

Two-Pillar Strategy For Growth

3

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

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

PEGPH20 Goal: Improve Targeting Of Co-Administered Cancer Therapies

4

5

HALO-301|Pancreatic: Phase 3 Design

• 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 Study

Preclinical Phase 1 Phase 2 Phase 3InCombination

withTumor

Gemcitabineand nab-Paclitaxel (Abraxane)

Pancreatic Cancer

Docetaxel(PRIMAL) NSCLC

Pembrolizumab(Keytruda®)

Gastric/ NSCLC

Eribulin(Halaven®)

BreastCancer(Eisai)

Additional Investigator Sponsored Trials in Pancreatic Cancer: SWOG, UCSF

Oncology Pipeline Update

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PEG-ADA2 Program Highlights

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Adenosine: Attractive immune checkpoint target

• Abnormally high levels accumulate in the TME • Binds to receptor checkpoints on immune cells• Contributes to an immunosuppressive TME

PEG-ADA2: An engineered human enzyme that targets adenosine

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

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

HTI-1511 Anti-EGFR ADC Program Highlights

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Engineered mAb with attenuated binding to human skin grafts

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

Utilization of next generation, Thiobridge chemistry• More homogeneous, stable

Safety profile met criteria for candidate nomination

Complete tumor responses observed in PDx tumor models

IND enabling studies underway

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 3 Approved

Herceptin SC OUS

Mabthera SC OUS

HYQVIA US

HYQVIA OUS

Daratumumab --

Rivipansel --

Bococizumab --

Humira --

3 Targets Identified --

ENHANZE: Our Novel Delivery Platform

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ENHANZE Momentum: Partnerships Accelerating, Royalty Pipeline Building

13

$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

• 2 new partnerships in 2015• Time from signing to clinic accelerating• 4 targets in clinic; new studies planned• Estimated 150 targets available that may benefit from ENHANZE

20152007 2012 20142006

Mid-single Digit Royalties on Net Sales

Roche Update: Herceptin SC1

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1) Information provided during Roche investor update (Apr. 19, 2016).

Financial Update

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1Q 2016 1Q 2015 % Change

Total Revenue $42.5 $18.7 128%

Royalty Revenue $11.4 $6.8 68%

Bulk rHuPH20 Sales $9.0 $6.1 48%

Hylenex® recombinant $3.9 $3.8 2%

Collaboration Revenue $18.2 $2.0 795%

First Quarter 2016 Financial Highlights1

$ U.S. in Millions (unaudited)

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

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1Q 2016 1Q 2015 % Change

Total Revenues $42.5 $18.7 128%

Total Operating Expenses $58.7 $32.6 80%

Cost of Product Sales $7.8 $6.5 20%

R&D Expense $40.1 $16.7 140%

SG&A Expense $10.8 $9.4 15%

Net Loss ($19.8) ($15.1) --

EPS ($0.16) ($0.12) --

Cash and marketable securities $238.6 $128.5 --

First Quarter 2016 Financial Highlights1

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

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

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Update: 2016 Financial Guidance

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Previous Revised

Revenue $110M to $125M $130M to $145M

Operating Expenses $240M to $260M $245M to $260M

Cash Flow $35M to $55M $45M to $65M

Year-end Cash $140M to $160M $150M to $170M

Value Enhancing Milestones Throughout 2016

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Goal Target Date

Initiate HALO-301|Pancreatic trial End of Q1 2016

HALO-Eisai Study in Breast Cancer Patients Initiated End of Q2 2016

Advance to Dose Expansion Phase in KEYTRUDA and PRIMAL Studies (pending number of dose cohorts)

2H 2016

Report mature data from HALO 202 | Pancreatic Q4 2016

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

2016

✓

First Quarter 2016Earnings Call

May 9, 2016