Media Release

• First clinical data from the safety lead-in of AIPAC-003 in metastatic breast cancer shows 90mg dosing of efti safe and well tolerated: 50% overall response rate, including one patient reporting a complete response (complete disappearance of all lesions), and a 100% disease control rate
• Subsequent to quarter end announced a positive preliminary response rate of 26.9% in first line metastatic head and neck squamous cell carcinoma patients with negative PD-L1 expression
• Preclinical studies of IMP761 progressing to clinical trials mid-CY2024
• Anne Anderson joins as independent non-executive director on Immutep’s Board

SYDNEY, AUSTRALIA, April 29, 2024 -- 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, provides an update on the ongoing development of its product candidates, eftilagimod alpha (efti) and IMP761 for the quarter ended 31 March 2024 (Q3 FY24).

EFTI DEVELOPMENT PROGRAM FOR CANCER

TACTI-002 (KEYNOTE-PN798) – Phase II clinical trial in 1L NSCLC
The TACTI-002 trial is ongoing with Immutep continuing to follow patients with 1L NSCLC (Part A) where, encouragingly, a median Overall Survival has not yet been reached in patients with high PD-L1 expression (TPS ≥50%). As previously reported at ESMO 2023, excellent median Overall Survival rates were seen across all levels of PD-L1 expression, including in patients expressing any PD-L1 (patients with a Tumor Proportion Score [TPS] of >1%) and patients with low PD-L1 expression (TPS 1-49%), with 35.5 months and 23.4 months reported respectively. Immutep has previously reported final data from Parts B and C of the TACTI-002 trial.

TACTI-003 (KEYNOTE-PNC34) – Phase IIb clinical trial in 1L HNSCC
The TACTI-003 multicenter Phase IIb trial evaluating efti in combination with MSD’s anti-PD-1 therapy KEYTRUDA® (pembrolizumab) is ongoing with a total of 171 first line head and neck squamous cell carcinoma (1L HNSCC) patients enrolled. Cohort A evaluating efti in combination with KEYTRUDA® as compared to KEYTRUDA® monotherapy (randomised) involves 138 patients with PD-L1 positive (Combined Positive Score [CPS] ≥1) tumours and Cohort B (non-randomised) includes 33 patients with PD-L1 negative tumours.

Subsequent to quarter end Immutep announced positive preliminary topline results from Cohort B. The investigational immuno-oncology combination demonstrates an overall response rate (ORR) of 26.9% and disease control rate (DCR) of 57.7% in 26 evaluable patients whose tumours do not express PD-L1 (CPS<1), according to RECIST 1.1, which compares favourably to historical controls.

The final number of evaluable patients in Cohort B is expected to be higher and additional data, including complete response rate, is expected to be released together with Cohort A data. Data collection, cleaning, and analysis continue for TACTI-003, and the Company expects to report the primary endpoint (overall response rate according to RECIST1.1) from Cohorts A & B in H1 CY2024.

TACTI-004 – Phase III registrational trial in 1L NSCLC
Immutep continued to advance the necessary preparations for the Phase III TACTI-004 trial in first line non-small cell lung cancer (1L NSCLC) during the quarter. Productive interactions with regulatory agencies as well as with other stakeholders and potential partners are ongoing. Immutep expects to announce the trial design for TACTI-004 in H1 CY2024.

AIPAC-003 – Integrated Phase II/III trial in MBC
Immutep announced the first clinical data from the 90mg dosing of efti, the highest dose ever administered to patients, from patients participating in the safety lead-in of the AIPAC-003 trial in metastatic breast cancer (MBC). Data from the six patients in the safety lead-in showed the 90mg dose of efti in combination with paclitaxel is safe and well tolerated. The initial efficacy data was also encouraging, with a 50% overall response rate, including one patient reporting a complete response (complete disappearance of all lesions), and a 100% disease control rate. The trial has proceeded to the randomised Phase II portion of study consisting of up to 58 evaluable patients who will receive 30mg efti or 90mg efti to determine the optimal biological dose of efti in combination with paclitaxel. Currently, 34 patients have been dosed in the randomised part. Further updates from AIPAC-003 will be provided in CY2024.

INSIGHT-003 – Phase I in non-squamous 1L NSCLC
The investigator-initiated INSIGHT-003 trial continued to enrol patients throughout the quarter, with 38 out of a total of 50 patients enrolled and safely dosed across six sites in Germany. INSIGHT-003 evaluates a triple combination therapy consisting of efti and an approved standard of care combination of chemotherapy (carboplatin and pemetrexed) and anti-PD-1 therapy (pembrolizumab) in patients as first line treatment in non-squamous NSCLC adenocarcinomas.

INSIGHT-005 – Phase I trial in Urothelial Carcinoma
The first patient in the investigator-initiated INSIGHT-005 trial was enrolled and safely dosed, as announced in January 2024. The study is evaluating efti and the anti-PD-L1 therapy BAVENCIO® (avelumab) in up to 30 patients with metastatic urothelial cancer and is jointly funded with Merck KGaA, Darmstadt, Germany.

EFTISARC-NEO – Phase II Trial in Soft Tissue Sarcoma
The investigator-initiated EFTISARC-NEO trial is ongoing with 14 patients now enrolled and safely dosed. The study evaluates efti in combination with pembrolizumab and radiotherapy in up to 40 soft tissue sarcoma (STS) patients in the neoadjuvant (prior to surgery) setting.

IMP761 DEVELOPMENT PROGRAM FOR AUTOIMMUNE DISEASE
IMP761 is the Company’s proprietary preclinical candidate and world’s first LAG-3 agonist that aims to treat the underlying cause of multiple autoimmune diseases. Throughout the quarter, Immutep progressed its pre-clinical development and IND-enabling toxicology studies for IMP761 to evaluate the safety and toxicity of its product candidate before entering first-in-human trials.

Subsequent to quarter end, Immutep entered into an agreement with the Centre for Human Drug Research (CHDR), a world-class institute in Leiden, the Netherlands specializing in cutting-edge early-stage clinical drug research, to perform a first-in-human clinical study of IMP761, which it expects to begin mid-CY2024.

GLAXOSMITHKLINE (GSK) - IMP731 (GSK2831781)
As detailed in Immutep’s half year report in February 2024, Immutep received from GSK a written notice of termination of its exclusive License and Research Collaboration Agreement with GSK entered into in 2010 for the development of GSK2831781, a LAG-3 depleting antibody derived from Immutep’s IMP731 antibody, targeting autoimmune disease, with an effective termination date of 30 May 2024. The Company expects no material impact on the financial statements due to the termination.

CORPORATE & FINANCIAL SUMMARY

Board Appointment
In February 2024, Anne Anderson was appointed as an independent non-executive director of Immutep Limited. Ms Anderson has extensive board and leadership experience serving Australian and international companies and brings considerable capability across capital markets, risk management and governance to Immutep’s Board.

Cash Flow Summary
During the quarter, Immutep continued to fund the advancement of its clinical trial programs for efti and preclinical program for IMP761 to create value for shareholders. The Company is well funded with a strong cash and cash equivalent balance as at 31 March 2024 of approximately $95.4 million, giving it an expected cash reach into early CY2026.

Cash receipts from customers in Q3 FY24 were $14k, compared to $38k in Q2 FY24. The net cash used in G&A activities in the quarter was $0.7 million, compared to $0.8 million in Q2 FY24. Payments of $310k to Related Parties comprises Non-Executive Directors’ fees and Executive Directors’ remuneration.

The net cash used in R&D activities in the quarter was $6.9 million, which is consistent with Q2 FY24. Payment for staff costs was $2.0 million in the quarter compared to $2.2 million last quarter.

Total net cash outflows used in operating activities in the quarter was $9.0 million compared to $5.5 million in Q2 FY24. This difference was mainly due to the receipt of $3.8 million in R&D tax grants in Q2 FY24.

About Immutep
Immutep is a clinical stage biotechnology company developing novel LAG-3 immunotherapy for cancer and autoimmune disease. We are pioneers in the understanding and advancement of therapeutics related to Lymphocyte Activation Gene-3 (LAG-3), and our diversified product portfolio harnesses its unique ability to stimulate or suppress the immune response. Immutep is dedicated to leveraging its expertise to bring innovative treatment options to patients in need and to maximise value for shareholders. For more information, please visit www.immutep.com.

Australian Investors/Media:
Catherine Strong, Citadel-MAGNUS
+61 (0)406 759 268; cstrong@citadelmagnus.com

U.S. Investors/Media:
Chris Basta, VP, Investor Relations and Corporate Communications
+1 (631) 318 4000; chris.basta@immutep.com