ASX/Media Release Immutep reports positive Overall Response Rate in its Phase II clinical trial in 1 st line NSCLC for PD-L1 all-comers TACTI-002 has met its primary objective for 1 st line non-small cell lung cancer (NS

positive Overall Response Rate

in its Phase II clinical trial in 1st line NSCLC

for PD-L1 all-comers

SYDNEY, AUSTRALIA 6 June 2022 Immutep Limited (ASX: IMM; NASDAQ: IMMP) ( Immutep or the

Company ), a biotechnology company developing novel LAG-3 related immunotherapy treatments for cancer and autoimmune disease, announces new data from

1st line NSCLC patients (Part A) of the Phase II TACTI-002 trial evaluating Immutep s lead product candidate, eftilagimod alpha ( efti or

IMP321 ) in combination with MSD s anti-PD-1 therapy KEYTRUDA (pembrolizumab) in 114 patients.

The data was presented in an Oral Presentation at the American Society of Clinical Oncology s (ASCO) 2022 Annual Meeting.

TACTI-002 Principal Investigator, Dr Enriqueta Felip of Vall d Hebron University Hospital Barcelona, Spain,

said: It is very encouraging to see the combination of efti plus pembrolizumab is showing favourable anti-tumour activity in patients with 1st line NSCLC. These responses were deep and

durable and there has also been a low patient discontinuation rate. I believe the combination of efti plus pembrolizumab warrants late stage clinical investigation.

Immutep CSO and CMO, Dr Frederic Triebel, noted: Our ORR by local read of 38.6% in 1st line

NSCLC patients is comparing favourably to historical results from anti-PD-1 monotherapies where response rates in PD-L1 all-comer trials are typically around 20%. We are particularly pleased to see encouraging responses across all PD-L1 status groups, showing that efti may kick start an

anti-tumour immune response even in patients with no or low PD-L1 expression. In addition, the combination of efti plus pembrolizumab has a safety profile consistent with that observed in previously reported

studies for pembrolizumab monotherapy. We continue to believe that efti, with its unique mechanism of action, may ultimately provide a very meaningful benefit to diverse sets of cancer patients including those with more limited treatment

Immutep CEO Marc Voigt said: We are delighted that patient outcomes are improved with the

combination of efti plus pembrolizumab across different patient groups. The data is encouraging for patients, as there is an unmet medical need particularly for those with NSCLC with no or low PD-L1

expression. We enlarged this part of the study in order to see if the strong earlier results in a smaller group of patients are holding true in more than a hundred patients. By biotech standards, we consider this to be a large patient population for

For Immutep, these highly favourable results are of strategic importance, as they support late stage development for an

attractive and very large adressible market, he said.

The 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., DCR, Duration of Response (DoR), PFS, Overall Survival (OS), and Safety assessments.

population and condition

A total of 114 patients with 1st line NSCLC were enrolled and

treated with efti plus pembrolizumab in 6 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 ~70% of patients having a Tumour Progression Score (TPS) of < 50%. 93% 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 (22%) for

non-metastatic disease. The trial reflects a typical patient population for this indication, including a mix of squamous/non-squamous disease and male/female

Key Findings from 1st line

NSCLC patients in TACTI-002 data cut-off date 15 April 2022

Primary analysis of primary endpoint by iRECIST ORR

Leighl et al, The Lancet 2019, http://dx.doi.org/10.1016/S2213-2600(18)30500-9

Mok et al, The Lancet 2019, http://dx.doi.org/10.1016/S0140-6736(18)32409-7

Table 1 Primary endpoint (ORR) results for 1st

line NSCLC patients from TACTI-002

Analysis by iRECIST DCR, DoR and PFS

Chart 1 Change in lesion size from baseline for 1st line NSCLC patients from TACTI-002

combination of efti plus pembrolizumab is safe and well-tolerated, continuing efti s good safety profile to date. Part A reports a low discontinuation rate, with only 9.6% of patients discontinuing due to study treatment related adverse events.

The safety profile to date is consistent with that observed in previously reported studies for pembrolizumab monotherapy except for local injection site reactions (erythema).

Mok et al, The Lancet 2019, http://dx.doi.org/10.1016/S0140-6736(18)32409-7

The combination of efti plus pembrolizumab is showing favourable efficacy in 1st line NSCLC in the PD-L1 all-comer population and in all PD-L1 status groups, and with a low treatment discontinuation rate. The data support continued

late stage development in this indication.

The Company will host a global webcast to discuss the new data from 1st line NSCLC patients participating

in its Phase II TACTI-002 trial including an analyst Q&A.

A replay of the webcast will be available after the event at www.immutep.com.

Immutep expects to report further

results from TACTI-002 in H2 calendar year 2022.

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 line.

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,

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:

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 s current 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 and infectious disease. Immutep is also developing an agonist of LAG-3 (IMP761) for

Additional LAG-3 products, including antibodies for immune response modulation, are being

developed by Immutep s large pharmaceutical partners.

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

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

Tim McCarthy, LifeSci Advisors

+1 (212) 915.2564; tim@lifesciadvisors.com

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

Limited, Level 33, Australia Square

264 George Street, Sydney NSW 2000