ASX/Media Announcement Immutep Reports Positive Phase II TACTI-002 Data Increasing benefit reported from patients with first line Non-Small Cell Lung Cancer (NSCLC): Improving Overall Response Rate (ORR) of 53% (earlier

ASX/Media Announcement

Immutep Reports Positive Phase II TACTI-002 Data

SYDNEY, AUSTRALIA April 28, 2020 Immutep Limited (ASX: IMM; NASDAQ: IMMP) ( Immutep or the

Company ), a biotechnology company developing novel immunotherapy treatments for cancer and autoimmune diseases, announces further positive interim data from its ongoing Phase II TACTI-002 study. The data

relates to the data cut-off date of 20 March 2020 and shows improving efficacy results.

being presented today as a poster short talk audio presentation as part of the high-impact paper presentation program by TACTI-002 Principle Investigator, Dr Martin Forster of University College London

Hospitals NHS Foundation at the American Association for Cancer Research (AACR) Virtual Annual Meeting.

is being conducted in collaboration with Merck & Co., Inc., Kenilworth, NJ, USA (known as MSD outside the United States and Canada). It is evaluating the combination of the Company s lead product candidate eftilagimod alpha

( efti or IMP321 ) with MSD s KEYTRUDA (pembrolizumab) in up to 109 patients with second line HNSCC or NSCLC in first and second line.

Immutep CSO and CMO, Dr Frederic Triebel said: These very positive results for stage 1 demonstrate the benefits for NSCLC

patients in receiving efti in combination with pembrolizumab. 53% of patients are now responding and we expect PFS to be more than 9 months. These consolidated results, with more tumour responses being confirmed by a second CT-scan and a longer follow up, are remarkable given that usually only 20% of patients respond to pembrolizumab monotherapy, if not pre-selected for high PD-L1 expression. It is also encouraging to see that 33% of HNSCC patients are responding, almost double the proportion that respond to pembrolizumab monotherapy and that the median PFS hasn t yet been reached

Immutep CEO, Marc Voigt stated: Efti is showing remarkable results for patients with NSCLC and HNSCC. These are

multi-billion-dollar markets, with NSCLC expected to reach US$33.9 billion and HNSCC US$2.8 billion by 2026 respectively1. As the treatment duration continues, we will update ORR and

PFS, positioning the Company strongly to advance efti in these indications.

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Key Findings (Data cut-off: 20 March 2020)

Stage 1 Part A (1st line NSCLC, N=17):

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Stage 1 Part C (2nd line HNSCC):

The combination treatment continues to be safe

and well tolerated with no new safety signals reported thus far.

TACTI-002 Recruitment Update

Trial recruitment continues to progress well, with 76 patients out of up to 109 already enrolled at 12 clinical sites across Australia, Europe, the UK and US.

Recruitment details for each Part are below and are current as at the date of today s announcement (not the data cut-off date of 20 March).

AACR Virtual Annual Meeting

A replay of the audio poster presentation with the presentation slides entitled, Initial results from a phase II study

(TACTI-002) in metastatic non-small cell lung or head and neck carcinoma patients receiving eftilagimod alpha (soluble lag-3

protein) and pembrolizumab , is available on the Company s website at www.immutep.com.

TACTI-002 (Two ACTive Immunotherapies) is being

conducted in collaboration with Merck & Co., Inc., Kenilworth, NJ, USA (known as MSD outside the United States and Canada). The study is evaluating the combination of efti with MSD s KEYTRUDA (or pembrolizumab, an anti-PD-1 therapy) in up to 109 patients with second line head and neck squamous cell

carcinoma or non-small cell lung cancer in first and second line.

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

single-arm, multicentre clinical study that is taking place in up to 12 study centres across the U.S., Europe, UK and Australia.

Patients participating in three Parts:

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. PD-L1 expression is typically reported in three

groups for NSCLC: < 1%, 1-49% and 50% (Tumour Proportion Score or TPS). Patients with a high PD-L1 status are typically

more responsive to anti-PD-1 monotherapy such as pembrolizumab, whereas those with low PD-L1 status are overall significantly

less responsive. Pembrolizumab monotherapy is registered in the US and the EU for first-line NSCLC patients with a TPS score 1% (US) and 50% (EU), reflecting

65% and 30% of all first line NSCLC patients, respectively.

More information about the trial can be found on Immutep s website or on

ClinicalTrials.gov (Identifier: NCT03625323)

Immutep is a globally active biotechnology company that is a leader in the development of LAG-3 related

immunotherapeutic products for the treatment of cancer and autoimmune disease. Immutep is dedicated to leveraging its technology and expertise to bring innovative treatment options to market for patients and to maximize value to shareholders.

Immutep is listed on the Australian Securities Exchange (IMM), and on the NASDAQ (IMMP) in the United States.

Immutep s current lead product

candidate is eftilagimod alpha ( efti or IMP321 ), a soluble LAG-3 protein (LAG-3Ig) based on the LAG-3

immune control mechanism. This mechanism plays a vital role in the regulation of the T cell immune response. Efti is currently in a Phase IIb clinical trial as a chemoimmunotherapy for metastatic breast cancer termed AIPAC (clinicaltrials.gov

identifier NCT02614833); a Phase II clinical trial being conducted in collaboration with Merck & Co., Inc., Kenilworth, NJ, USA (known as MSD outside the United States and Canada) referred to as

TACTI-002 to evaluate a combination of efti with KEYTRUDA (pembrolizumab) in several different solid tumours (clinicaltrials.gov identifier

NCT03625323); a Phase I clinical trial being conducted in collaboration with Merck KGaA, Darmstadt, Germany and Pfizer Inc. referred to as INSIGHT-004 to evaluate a combination of efti with avelumab

(clinicaltrials.gov identifier NCT03252938); and a Phase I combination therapy trial in metastatic melanoma termed TACTI-mel (clinicaltrials.gov identifier NCT02676869).

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Additional LAG-3 products, including antibodies, for immune response

modulation in autoimmunity and cancer are being developed by Immutep s large pharmaceutical partners. Immutep is also developing an agonist of LAG-3 (IMP761) for autoimmune disease.

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

Further information can be found on the Company s website www.immutep.com or by contacting:

Australian Investors/Media:

+61 (0)406 759 268; cstrong@citadelmagnus.com

Garth Russell, LifeSci Advisors

+1 (646) 876-3613; garth@lifesciadvisors.com

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