ALX Oncology : Corporate Presentation

ALX Oncology

Corporate Presentation

May 2024

Forward-looking statements

Certain information set forth in this presentation contains "forward-looking information", under applicable laws collectively referred to herein as forward- looking statements. Except for statements of historical fact, information contained herein constitutes forward-looking statements and includes, but is not limited to the (i) results and cost and timing of our product development activities and clinical trials; (ii) completion of the Company's clinical trials that are currently underway, in development or otherwise under consideration; (iii) our expectations about the timing of achieving regulatory approval and the cost of our development programs;

1. projected financial performance of the Company; (v) the expected development of the Company's business, projects, collaborations and joint ventures; (vi) execution of the Company's vision and growth strategy, including with respect to future M&A activity and global growth; (vii) sources and availability of third-party financing for the Company's research and development; (viii) future liquidity, working capital, and capital requirements; and (ix) industry trends. These and other risks are described more fully in ALX Oncology's filings with the Securities and Exchange Commission ("SEC"), including ALX Oncology's Annual Report on Form 10- K and other documents ALX Oncology files with the SEC from time to time.

Although forward-looking statements contained in this presentation are based upon what management of the Company believes are reasonable assumptions, there can be no assurance that forward-looking statements will prove to be accurate. Actual results and future events could differ materially from those anticipated in such statements. The Company undertakes no obligation to update forward-looking statements if circumstances or management's estimates or opinions should change except as required by applicable securities laws.

This presentation concerns product candidates that are under clinical investigation, and which have not yet been approved for marketing by the U.S. Food and Drug Administration. These product candidates are currently limited by federal law to investigational use, and no representation is made as to their safety or effectiveness for the purposes for which they are being investigated.

This presentation also contains estimates and other statistical data made by independent parties and by ALX Oncology relating to market size and growth and other industry data. This data involves a number of assumptions and limitations, and you are cautioned not to give undue weight to such estimates. In addition, projections, assumptions, and estimates of ALX Oncology's future performance and the future performance of the markets in which it operates are necessarily subject to a high degree of uncertainty and risk.

2

ALX Oncology: The CD47 Leader

ALX Oncology is advancing a highly differentiated immuno-oncology pipeline led by evorpacept, a potential best and first-in-class CD47 innate immune system checkpoint inhibitor that has been studied in over 500 patients

Evorpacept is the first CD47 inhibitor to demonstrate robust clinical activity and a differentiated safety profile across both solid and hematologic tumors highlighted by the first positive randomized data in the field in gastric cancer in Q4 '23

A prespecified interim analysis of ASPEN-06, a randomized Ph2 study for the treatment of advanced HER2+ gastric/GEJ cancer, showed a confirmed overall response rate for the evorpacept arm of 52% vs. 22% for control and encouraging early durability

Multiple positive clinical studies across NHL, gastric, and head and neck (HNSCC) have been completed to date and currently pursuing additional studies in combination with 3 therapeutic classes: anti-cancer antibodies, checkpoint inhibitors and ADCs

Significant upcoming milestones anticipated in 2024 for evorpacept include final top line results from the Ph2 gastric/GEJ study, results from two randomized Ph2 studies in HNSCC, and new clinical data in breast, and urothelial cancer (ASCO 2024)

Expanding evorpacept to new indications and building a strong pipeline beyond evorpacept supported by multiple pharma partnerships and a strong balance sheet with cash runway into early 2026

3

Evorpacept: A first-in-class approach to targeting CD47

	SIRPα	CD47
Macrophage
Don't eat me	Cancer
		cell
	Fc
	receptor

Fc receptor

Macrophage	Red
Don't eat me
blood

SIRPα	CD47	cell

Target cells overexpress CD47 to evade

destruction by macrophages

High affinity CD47 binding domains of SIRPα

Inactive

Fc domain

Evorpacept

A differentiated CD47 blocker

4

Evorpacept targets the CD47 checkpoint

Macrophage

			Cancer
			cell
	Fc
	receptor
	Evorpacept
	Fc
	receptor
Macrophage			Red
			blood
	SIRPα	CD47	cell

Complete CD47 blockade

without targeting blood cells

Macrophage

Anti-cancer antibody

Cancer cell

Evorpacept

Macrophage	Red
	blood
	cell

Combined with cancer therapy to

specifically target cancer cells

5

Conventional CD47 targeting is more toxic and less efficacious

	SIRPα	CD47
Macrophage
Don't eat me	Cancer
		cell
	Fc
	receptor

Fc receptor

Macrophage	Red
Don't eat me
blood

SIRPα	CD47	cell

CD47 is widely expressed in both

healthy and cancer cells

Macrophage

Conventional

CD47 blocker

Cancer cell

Conventional

CD47 blocker

Red blood cell

Macrophage

Indiscriminate CD47 inhibition with an

active Fc will target healthy cells

6

Evorpacept has demonstrated consistent tolerability and robust clinical activity vs. conventional approaches

				Randomized Phase
evorpacept	evorpacept	evorpacept		2 trials with anti-
+	+	+	evorpacept	cancer antibodies
Keytruda	Herceptin	Rituxan		and checkpoint
Inactive
			inhibitors ongoing

Fc domain

Evorpacept

Phase 1b proof of	Phase 1b proof of	Phase 1b proof of
principle	principle	principle

Hematologic	Hematologic	Hematologic	Hematologic
toxicity signal	toxicity signal	toxicity signal	toxicity signal

Active	Lemzo-	TTI-622	TTI-621	Magrolimab	Removed from
parlimab	Gilead Pipeline

Fc domain

Conventional

CD47 Blockers

7

Evorpacept's consistent activity profile is due to its distinct molecular design

Evorpacept enhanced preclinical antitumor activity across multiple classes of therapies…

			Evo +											Evo +
2000													Cetuximab
	Rituximab					Evo +
1500										Trastuzumab
Volume + SEM)
1000
3
Tumor (mm
500
0	12	14	16	18	20	22	24	26	500
10
		Day post implantation		0
									8	12	16	20	24	28	32	36
											Days post implantation

…translated to 5 positive clinical studies across both solid and hematological malignancies

		Evo +					Evo +
		Anti-PD-L1
			Obinutuzumab
volume ± SEM)	400
				1500
3
Tumor (mm	200				*	1000
	0					500
	6	9	12	15
	3	0
		Days post implantation	16	18 20 22 24	26	28	30	32
		14

Kauder et al. 2018	Days post implantation

Evo +

Daratumumab

8

Evorpacept has demonstrated a consistent tolerability profile across multiple tumors & combinations

Active vs inactive Fc in vivo data

Treatment related	evorpacept + Herceptin	evorpacept +	evorpacept +
+ Cyramza + chemo	Keytruda	Keytruda
adverse events	(N=18)	+ chemo (N=13)	(N=52)
Total n (%)	≥Grade3	Total n (%) ≥Grade3	Total n (%) ≥Grade3
Fatigue	2 (11.1%)	-	1 (7.7%)	-	6 (11.5%) -

of Predose	(Day -5)
%

125

100

75

50

25

0

								Red Blood Cells
			(Active Fc)				(Inactive Fc)
						***																																			200
		****																																		ofPredose	150
																																									(Day-5)
																																								%	100
																																								50
																																										0
-5		3	5			2			-5	3			5			2
															1																			1

Days post dose

Platelets

(Active Fc) (Inactive Fc)

***

-5	3	5	2	-5	3	5	2
			1				1

Days post dose

Rash / dermatitis acneiform	4 (22.2%)	-	-	-	5 (9.6%)	-
AST increased	-	-	-	-	9 (17.3%)	-
Platelets decreased	-	-	-	-	4 (7.7%)	2 (3.8%)
ALT increased	-	-	-	-	7 (13.5%)	1 (1.9%)
Pruritus	2 (11.1%)	-	-	-	5 (9.6%)	-
Pyrexia	-	-	-	-	3 (5.8%)	-
Decreased appetite	-	-	-	-	2 (3.8%)	-
Anemia	1 (5.6%)	-	1 (7.7%)	1 (7.7%)	5 (9.6%)	1 (1.9%)
Infusion reaction	-	-	-	-	4 (7.7%)	-
Neutropenia / neutrophil count decrease	-	-	1 (7.7%)	-	2 (3.8%)	1 (1.9%)
Nausea	-	-	-	-	2 (3.8%)	-
Alkaline phosphatase incr	-	-	-	-	3 (5.8%)	-
Arthralgia	-	-	-	-	3 (5.8%)	-

	150
ofPredose	125
(Day-5)
	100
	75
%	50
	25
	0

Kauder et al. 2018

CD-1 mice received 30 mg/kg IV single dose ****p<0.0001, ***p<0.001

White Blood Cells

(Active Fc) (Inactive Fc)

****

-5	3	5	2	-5	3	5	2
			1				1

Days post dose

WBC decreased	-	-	-	-	3 (5.8%)	-
Myalgia	-	-	-	-	2 (3.8%)	-
Diarrhea	3 (16.7%)	-	-	-	-	-
Urticaria	3 (16.7%)	-	-	-	-	-
Lymphocyte count decreased	1 (5.6%)	1 (5.6%)	-	-	-	-
Headache	1 (5.6%)	-	-	-	-	-
Stomatitis	1 (5.6%)	-	-	-	-	-
Back pain	1 (5.6%)	-	-	-	-	-
Vision blurred	1 (5.6%)	-	-	-	-	-
Abdominal pain / abdominal pain upper	1 (5.6%)	-	-	-	-	-
Hypersensitivity	-	-	1 (7.7%)	1 (7.7%)	-	-
Pneumonitis	-	-	1 (7.7%)	-	-	-
Constipation	-	-	-	-	-	-
Vomiting	-	-	-	-	-	-

The lack of preclinical toxicity due to the inactive Fc in vivo has translated to a well-tolerated profile in clinic

Phase 1 ASPEN-01 cohorts. For combination cohort of evorpacept plus Keytruda, treatment related adverse events occurring in >1 subject in all histologies at 10 & 15 mg/kg QW; data as of April 1, 2020. For combination cohorts of evorpacept plus Keytruda and chemotherapy (5FU, platinum) or plus Herceptin and chemotherapy (Cyramza, paclitaxel), all treatment related adverse events are reported; data as of September 01, 2021.

9

Evorpacept's differentiated design results in differentiated safety profile and robust clinical activity

Higher affinity CD47 binding

Inactive Fc domain

Lower molecular

weight

Antibody-like

pharmacokinetics

Evorpacept

More potently blocks CD47 signal on cancer cells

Less "sink effect" = more targeted

No known dose dependent cytopenia = higher dosing

Increased solid tumor penetration and

higher effective dosing

Long half life = less frequent dosing and matching regimen with combinations

Robust clinical

activity

Best-in-class safety

profile

Strong solid tumor

activity

Broad combination

potential

10