ASX/Media Release Immutep Announces Compelling Clinical Results from Phase II Trial Utilizing its First-in-Class Soluble LAG-3 Protein, Eftilagimod Alpha, in 1st Line NSCLC at SITC 2022 Annual Meeting Overall response ra

Immutep Announces Compelling Clinical Results from Phase II Trial Utilizing its

First-in-Class Soluble

LAG-3 Protein, Eftilagimod Alpha, in 1st Line NSCLC

at SITC 2022 Annual Meeting

Overall response rate (ORR) increases to 40.4%, according to iRECIST, in TACTI-002 all-comer PD-L1 Phase II trial in 1st line non-small cell lung cancer (1L NSCLC)

ORR improved across all PD-L1 status groups by central assessment compared with data

reported at ASCO 2022, including 48.3%, 44.7%, 55.0%, and 31.3% ORR in patients with PD-L1 TPS of >1%, 1-49%, >50%, and <1%, respectively

Interim median Duration of Response (DoR) of 21.6 months, compares favourably to historical controls including anti-PD-1 therapy combined with chemotherapy

patients in trial having PD-L1 TPS <50% who are less likely to respond to anti-PD-1 monotherapy, promising results achieved in

secondary endpoint of interim median Progression Free Survival (PFS) with overall PFS of 6.6 months and 9.3 months PFS in TPS >1%

Significant increase in IFN- and CXCL10 serum biomarkers for systemic TH1 response;

substantiates efti s unique stimulation of the immune system also seen in the randomized AIPAC Phase IIb trial in Breast Cancer

Webcast to Discuss Results at 5pm ET (9am AEDT) Today

SYDNEY, AUSTRALIA 11 November 2022 Immutep Limited (ASX: IMM; NASDAQ: IMMP) ( Immutep or

the Company ), a clinical-stage biotechnology company developing novel LAG-3 immunotherapies for cancer and autoimmune disease, today announces compelling new clinical data from the TACTI-002 all-comer PD-L1 Phase II trial evaluating Immutep s lead product candidate, eftilagimod alpha ( efti or

IMP321 ) in combination with MSD s (Merck & Co., Inc., Rahway, NJ., USA) anti-PD-1 therapy

KEYTRUDA (pembrolizumab) in 114 patients with 1L NSCLC.

The new data was presented today in a

late-breaking abstract oral presentation (Abstract #1470) at the 37th Annual Society of Immunotherapy of Cancer (SITC) Meeting by Wade T. Iams, MD, Assistant Professor of Medicine,

Vanderbilt-Ingram Cancer Center Division of Hematology/Oncology. Today s presentation followed the abstract data that had been discussed at the SITC 2022 Press Conference on 8 November 2022.

Dr. Iams stated, The encouraging ORR, PFS and DCR presented today at SITC build on the promise of efti, a first-in-class soluble LAG-3 protein, to uniquely engage the innate and adaptive immune system to enhance the clinical effect of

pembrolizumab. Responses in TACTI-002 were seen across all PD-L1 expression levels and histologic types, including in patients with

PD-L1 TPS less than 50%. The deep and durable responses driven by efti plus pembrolizumab continue to be favorable with median DoR of 21.6 months.

Immutep CSO and CMO, Dr Frederic Triebel, noted, The strengthening of efficacy, with improving

overall response rates across all levels of PD-L1 stratification in first-line NSCLC patients, with no new safety signals, is quite encouraging. We are pleased to see ORR reach 40.4%, which compares favourably

to the approximate 20% response rates in other PD-L1 all-comer trials utilizing anti-PD-1

monotherapy. Importantly, this additional clinical benefit is occurring with a safety profile consistent with that observed in previously reported studies for pembrolizumab monotherapy. We are also excited to share the first pharmacodynamic data

from efti s combination with pembrolizumab, showing significant elevation of IFN- and the CXCL10 chemokine serum biomarkers for systemic TH1 response. Similar to the immune response biomarker data

seen in efti s randomized Phase IIb trial in breast cancer, this further substantiates efti s novel ability to engage and activate the immune system.

Immutep CEO Marc Voigt added, We are pleased to see patient outcomes improving yet again, and continue to believe that efti, with its unique

mechanism of action targeting a subset of MHC class II molecules to mediate antigen-presenting cell activation, holds significant potential to benefit cancer patients. This includes those with PD-L1 expression

levels below 50% that represent the vast majority of patients with NSCLC. Based on this compelling data in this large Phase II trial, coupled with the large market opportunity and high unmet need for more durable and tolerable options, we continue

to push forward with our late-stage clinical development plans in frontline NSCLC in combination with anti-PD-1 therapy.

Key Findings from TACTI-002 Phase II Trial in 1L NSCLC Patients (N=114) Data cut-off date 1 July 2022:

Table 1 Overall Response Rates - (data

cut-off 1 July 2022)

Chart 1 Efficacy: Spider Plot

Chart 2 Interim Duration of Response (DoR) by iRECIST

primary endpoint was ORR according to iRECIST and local read. The data announced today represents the primary analysis of mature data of this endpoint. Secondary endpoints include ORR by RECIST 1.1 (consistent with iRECIST), DCR, DoR, PFS, Overall

Survival (OS), and Safety assessments.

Patient population and condition

A total of 114 patients with 1L NSCLC were enrolled and treated with efti plus pembrolizumab in six countries across 19 trial sites throughout Europe, the

United States, and Australia. Importantly, the patients were enrolled without any selection for PD-L1 status (PD-L1 all-comers),

a biomarker indicating the likelihood of response to pembrolizumab. The trial was confirmed as a PD-L1 all-comer trial with ~75% of patients having a Tumour

Progression Score (TPS) of < 50%. 99% of patients had metastatic disease at study entry and the patients had an ECOG performance status of 0 (37.7%) or 1 (62.3%). Treatment prior to study start included radiotherapy (33%), surgery (20%) and

systemic therapy (23%) for non-metastatic disease. The trial reflects a typical patient population for this indication, including a mix of squamous/nonsquamous disease and male/female representation.

The combination of efti plus

pembrolizumab is showing encouraging efficacy in 1L NSCLC patients across all PD-L1 status groups, including in PD-L1 low and

PD-L1 negative patients. The combination is very well tolerated, and the low discontinuation rate is consistent with pembrolizumab monotherapy. The data support continued late-stage development in this

The Company will host a global

webcast to discuss the new data from 1L NSCLC patients participating in its Phase II TACTI-002 trial including an analyst Q&A.

KEYTRUDA is a registered trademark of Merck Sharp & Dohme

LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.

About Eftilagimod Alpha (Efti)

Efti is Immutep s proprietary soluble LAG-3 clinical stage candidate that is a first-in-class antigen presenting cell (APC) activator for the treatment of cancer, capitalising on LAG-3 s unique characteristics to stimulate both innate and

adaptive immunity. Efti binds to and activates antigen presenting cells via MHC II molecules leading to expansion and proliferation of CD8+ (cytotoxic) T cells, CD4+ (helper) T cells, dendritic cells, NK cells, and monocytes. It also upregulates the

expression of key biological molecules like CXCL10 that further boost the immune system s ability to fight cancer.

Efti is under evaluation for a

variety of solid tumours including non-small cell lung cancer (NSCLC), head and neck squamous cell carcinoma (HNSCC), and HER2 /HR+ metastatic breast cancer. Its favourable safety profile enables various

combinations, including with anti-PD-[L]1 immunotherapy and/or chemotherapy. Efti has received Fast Track Designation in 1st line HNSCC and in 1st line NSCLC from the

United States Food and Drug Administration (FDA).

About the TACTI-002 Trial

TACTI-002 (Two ACTive Immunotherapies) is being conducted in collaboration with Merck & Co., Inc., Rahway, NJ,

USA (known as MSD outside the United States and Canada). The study is evaluating the combination of eftilagimod alpha (efti) with MSD s anti-PD-1

therapy KEYTRUDA (pembrolizumab) in patients with second line head and neck squamous cell carcinoma or non-small cell lung cancer in first and second

The trial is a Phase II, Simon s two-stage, non-comparative,

open-label, single-arm, multicentre clinical study that is taking place in study centres across Australia, Europe, and the US.

Patients participate in one of the following:

TACTI-002 is an all-comer study in terms of PD-L1 status, a well-known predictive marker for response to pembrolizumab monotherapy especially in NSCLC and HNSCC. More information about the trial can be found on Immutep s website or on ClinicalTrials.gov

(Identifier: NCT03625323).

Immutep is a clinical stage biotechnology company leading the development of LAG-3 related immunotherapy products for

the treatment of cancer and autoimmune disease. The Company is dedicated to leveraging its technology and expertise to bring innovative treatment options to market for patients and to maximise value to shareholders.

Immutep s lead product candidate is eftilagimod alpha ( efti or IMP321 ), a soluble LAG-3

fusion protein (LAG-3Ig), which is a first-in-class antigen presenting cell (APC) activator being explored in cancer in multiple

clinical trials. The Company is also developing an agonist of LAG-3 (IMP761) for autoimmune disease. Additional LAG-3 product candidates, including antibodies for immune

response modulation, are licensed to and being developed by Immutep s large pharmaceutical partners.

Further information can be found on the

Company s website www.immutep.com or by contacting:

Australian Investors/Media:

Catherine Strong, Citadel-MAGNUS

McCarthy, LifeSci Advisors

+1 (917) 679 9282; tim@lifesciadvisors.com

This announcement was authorised for release by the Board of Immutep Limited.

Immutep Limited, Level 33, Australia Square

264 George Street, Sydney NSW 2000