Antisense Therapeutics : Quarterly Report and Appendix 4C

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• Positive Opinion received on PIP from PDCO for EU and ratified by EMA
• Positive PIP Decision from UK MHRA
• ATL1102 Toxicology Protocol submitted to US FDA and update on PRV status
• $22.6 million raised via Placement and Entitlement Offer
• Dr Gil Price appointed as a non-executive director
• 2021 AGM
• ATL1102 Intellectual Property Update

Antisense Therapeutics Limited (Antisense or Company) is pleased to provide its Appendix 4C and quarterly update for the period ended 31 December 2021.

Positive Opinion received on ATL1102 Paediatric Investigation Plan and subsequently ratified by EMA

During the quarter the Paediatric Committee (PDCO) of the European Medicines Agency (EMA) adopted a positive final Opinion on its Paediatric Investigation Plan (PIP) for the development of ATL1102 for Duchenne muscular dystrophy (DMD) following the PDCO meeting on 15 October 2021. Subsequent to the reporting of this news, the Company has received formal ratification by the EMA of this decision.

Phase IIb/III trial

The Phase IIb/III clinical trial is a multicentre, randomised, double-blind,placebo-controlled study to determine the efficacy, safety, and pharmacokinetic profile of ATL1102 (25 mg and 50 mg) administered once weekly by subcutaneous injection for 52 weeks in non-ambulatory participants with DMD, to be conducted as a potentially pivotal (approvable) trial with a follow-on open label extension trial. Participants will be randomised to either 25 mg ATL1102, 50 mg ATL1102 or placebo in a 1:1:1 ratio with stratification by corticosteroid use. Up to 114 participants are to be enrolled (38 per treatment arm) with 108 participants expected to complete the trial. Additional trial details and timelines are outlined in the investor presentation lodged with the ASX on 1 November 2021.

As previously announced, ANP has appointed globally renowned Clinical Research Organisation (CRO) Parexel to conduct and manage the Phase IIb/III European trial. Parexel are finalising evaluations of the trial sites via site inspections in the United Kingdom, Netherlands, Germany, Italy, France, Belgium, Spain, Bulgaria and Turkey for selection of the sites to participate in the study. Trial start up activities are underway as outlined in the Company's 14 December 2021 announcement with the anticipated study timelines as noted in the 1 November 2021 investor presentation lodged by the Company with the ASX.

Professor Thomas Voit MD (Director of NIHR GOSH UCL Biomedical Research Centre, UK) has been appointed as the Coordinating Principal Investigator (CPI) of the trial.

Positive PIP Decision received from UK MHRA

In December 2021 the Company received a positive Decision from the Medicines and Healthcare products Regulatory Agency (MHRA) in the UK on the UK Paediatric Investigation Plan (PIP) submission for the development of ATL1102 for Duchenne muscular dystrophy (DMD) (a separate PIP submission was made to the MHRA following the UK's withdrawal from the European Union). The UK is a key location for the conduct of the study and is the base of our CPI, Professor Thomas Voit.

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In December 2021 the Company submitted to the US Food and Drug Administration (FDA) the protocol synopsis for a nine-month chronic monkey toxicology study to support the dosing of patients with ATL1102 beyond six months in US for DMD or any other clinical application of ATL1102. The Company is expecting to receive feedback from the FDA on the protocol in 1Q'22.

A prior Type C guidance meeting held with US FDA provided the Company with clarity on the requirement for the chronic monkey study and design of a Phase IIb/III trial for the US. Given the apparent high-level alignment between EMA and FDA on Phase IIb/III study requirements, the feedback from the FDA provides the Company with the opportunity to engage with the agency to streamline the regulatory processes and to the extent possible harmonize the Company's overall global clinical development plans. The Company considers that it has potential optionality in its actions with FDA including to take the EU Phase IIb/III data to the FDA to be assessed as supportive data for a future marketing application or should the data warrant it, possibly an approval of ATL1102 for DMD without further trials.

FDA interactions to explore the optionality highlighted above are to continue in parallel with the conduct of Phase IIb/III pivotal trial in Europe. The timing of the initiation of the nine-month toxicology study will be dependent on these continued interactions with the agency.

An important consideration in the clinical and regulatory strategy outlined above is the news announced by ANP on 30 September 2020 that the US FDA had granted a Rare Pediatric Disease Designation to ATL1102 for the treatment of DMD. Should the Phase IIb/III pivotal trial in Europe be successful, the Company believes it could be in a position to receive a rare pediatric disease priority review voucher (PRV) if it obtains FDA approval for ATL1102 in the DMD indication (as the drug's first approval) before September 30, 2026 (being the extended sunset date of the RPD Priority Review Voucher Program approved by the US Congress). The Company may then choose to sell its PRV to use it as a source non- dilutive capital. From 2017 - 2021, sales of PRVs ranged between US$80 - $150 million.

$22.6 million raised via Placement and Entitlement Offer

During the quarter, the Company received gross proceeds of $22.6 million via a capital raising comprising a placement to institutional and sophisticated investors and a follow-on Entitlement Offer to shareholders. The funds received will be deployed towards preparation activities for initiation of the Company's pivotal Phase IIb/III trial of ATL1102 for DMD in Europe as detailed in ANP's recent announcements and the Company's AGM presentation lodged with the ASX on 15 December 2021.

Dr Gil Price, Antisense Therapeutics' US-based Consultant Medical Director appointed to the Company's board as a non-executive director

In line with the board's strategy of strengthening the Company's clinical and scientific resources and governance ahead of the imminent initiation of Phase IIb clinical trial of ATL1102 in DMD in Europe, the Board of Director has appointed Dr Gil Price as a Non-Executive Director. Dr Price brings to the board a deep understanding and experience in DMD drug development as a clinical physician and extensive commercial development experience combined with a depth of expertise across clinical asset investment strategy, evaluation, financing and execution gained serving as director on multiple boards of private, not- for-profit and public entities, including as non-executive director of Sarepta Therapeutics, Inc. (2007- 2016).

Dr Price's engagement with Key Opinion Leaders in the treatment of DMD and DMD Patient Advocacy Groups has helped increase the awareness of the Company's ATL1102 for DMD development program

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2021 Annual General Meeting

The Company's Annual General Meeting of shareholders was held on the 15 December 2021. All resolutions were carried on a poll and were passed with the majority of the vote (over 94%) in favour of the resolutions.

Three long serving non-executive directors (Bob Moses, Dr Graham Mitchell and William Goolsbee) retired at the AGM with non-executive directors Dr Charmaine Gittleson and Dr Gil Price (who had recently joined the board to help strengthen the Company's clinical and scientific resources and governance) elected by shareholders at the AGM with 99.95% of the vote in favour of their appointment.

The Chair then outlined the Company's proposed strategic plan and high-level key strategic factors for success. The Managing Director (MD) then highlighted the recent capital raising that had significantly strengthened the Company's balance sheet, noting that it was the most capital the Company had accessed in its history. The MD then advised of the substantial progress made with both European and US regulatory authorities (outlined earlier in this report) in regards to advancing the ATL1102 DMD program in these key markets and advancements in the Company's research collaboration with the Murdoch Children's Research Institute (MCRI), where animal studies were in preparation for initiation in Q1'22 (dosing of animals anticipated to commence early next month with first data due Q3'22, as noted in the AGM presentation). The MD also outlined the Company's capital management plans and commercialisation considerations for ATL1102 in DMD, noting that the Company was gearing up to potentially take ATL1102 all the way to through approval in Europe and possibly to market in that territory and the major value creation potential that such an initiative could deliver for shareholders.

ATL1102 Intellectual Property Update

Since reporting on the status of the Company's intellectual property portfolio in the 2021 Annual Report, the Company has advanced its patent portfolio as follows:

• International application PCT/AU2018/051353 covering ATL1102 treatment of Duchenne muscular dystrophy (DMD) has been progressed into the examination phase in Australia, Brazil, Canada, China, Japan, New Zealand, South Korea and Europe, together with US continuation-in part 16/404561 to protect the invention to 2039;
• International application PCT/AU2020/050445 covering ATL1102 treatment of other muscular conditions has been progressed with filings in the national phase in Australia, Brazil, Canada, China, Japan, New Zealand, South Korea, the USA and the regional phase in Europe, to protect the invention to 2040;
• New Australian Provisional Patent application 2021903024 was filed 20 September 2021 covering new ATL1102 effects on plasma proteins (proteomics) and ATL1102 applications in new potential disease settings including diabetic, respiratory and age-related diseases;

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The Company continued its communication and active engagement with key opinion leaders, potential collaborators, investors and commercial partners as a key operational priority. During the quarter the Company presented and participated at the following events:

• Virtual Investor Roadshows - October - November 2021
• Opentrader, Trading Edge; Post lockdown trading webinar - Australia, 17 November 2021
• ShareCafe Due Diligence Webinar - Australia, 23 November 2021
• Spark Plus Healthcare Day Webinar - Singapore, 25 November 2021
• 2021 Annual General Meeting - Melbourne, 15 December 2021

Broker Research & Other Reports

Several leading Australian healthcare research analysts have released positive research notes on the Company during the quarter (reports are available on ANP website: https://www.antisense.com.au/broker-other-reports/):

"Paediatric Investigation Plan Almost Certain To Get the Tick and Other Notable Events" - Marc Sinatra, Corporate Connect

"Securing funding for DMD pivotal trial" - Dennis Hulme, Taylor Collison

"Transformational Capital Raise for Antisense Therapeutics" (with inclusion into Bioshares Model Portfolio) - Mark Pachacz, Bioshares

"Phase 2/3 here we come" - Stuart Roberts, Stocks Down Under

"Leaps and stepping stones" - Iain Wilkie / Scott Power, Morgans Financial "Comprehensive Research Report" - Marc Sinatra, Corporate Connect

Cash Flow

As at 31 December 2021 the Company reported cash of $23.48 million.

The Company continues to efficiently manage expenditure planned for continuation of the regulatory interactions with EMA and US FDA, preparations for the conduct of Phase IIb clinical trial of ATL1102 in DMD in Europe as well as advancement of potential new indications for ATL1102. During the quarter the net expenditure incurred on those activities amounted to $1.28 million.

During the quarter the Company made payments to related parties of the entity and their associates as disclosed in Item 6 of the Appendix 4C amounting to $343,412. The payments related to salaries, directors' fees and consulting fees on normal commercial terms.

This announcement has been authorised for release by the Board.

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Rule 4.7B

Appendix 4C

Quarterly cash flow report for entities subject to Listing Rule 4.7B

Name of entity