Aktis Oncology : 5.5.26 AKY 2519 Phase 1b Trial Update Conference Call Presentation

Published: 2026-05-05 08:11:14 ET AKTS

Published on 05/05/2026 at 08:11 am EDT

May 5, 2026

Agenda

Maximizing the impact of radiopharmaceuticals

Accomplished

Leadership Team

Strong

Balance Sheet

Isotope Supply

from Multiple Partners

Resilient and Scalable

Manufacturing

Novel and Differentiated

Platform

Pillars of value

Two Clinical Programs Addressing Large Market Tumor Types

Imaging Proof-of-Concept in Patients

Pipeline

of Potential First-in-

Class Programs

Eli Lilly & Co. Discovery Collaboration

Aktis is advancing a novel pipeline for large patient populations

PROGRAM

TARGET/INDICATION

DISCOVERY

IND-ENABLING

PHASE 1b

PHASE 2/3

UPCOMING MILESTONES

AKY-1189

Nectin-4 expressing solid tumors

Fast Track Design

ation*

Ph1b ongoing

Prelim data in 1Q'27

AKY-2519

B7-H3 expressing mCRPC

Imaging/ dosimetry data at ASCO 2026 Ph1b initiated; Prelim data in 2027

B7-H3 expressing

lung, colorectal, and other

solid tumors

Imaging/ dosimetry data at ASCO 2026

Ph1b start 2H'26

Multiple Programs

Undisclosed

Note: AKY-1189 and AKY-2519 programs include both imaging and therapeutic radioconjugates. 5

*Fast Track Designation in locally advanced or metastatic urothelial cancer.

Broad clinical development strategy for AKY-2519

Phase 1b trial for metastatic castration-resistant prostate cancer (mCRPC) initiated: Announced yesterday

Phase 1b basket trial for lung, colorectal, and other solid tumor cancers initiation: Expected 2H'26

B7-H3 is a clinically validated high-potential multi-tumor target

Brain

Normal

Vessels

Tum. cells & vessels

Normal Tissue

Colon

Breast

Tumor

Lung

Kidney

B7-H3 highly expressed in various solid tumors, including mCRPC, lung cancer and breast cancer, and minimal expression in normal organs1

High expression has been associated with poor overall survival in RCC2, ESCC3, OC,

Pancreatic

PC, NSCLC and other tumor types4

High expression is correlated with non-responsiveness to anti-PD-1 Tx in NSCLC5,6

mCRPC=metastatic castration-resistant prostate cancer; RCC=renal cell carcinoma; ESCC=esophageal squamous cell carcinoma; OC=ovarian cancer; PC=prostate cancer; NSCLC=non-small cell lung cancer.

1Seaman et al. Cancer Cell. 2017; 2Crispen et al. Clin Cancer Res. 2008; 3Chen et al. Am J Transl Res. 2015; 4Zang et al. NPJ Breast Cancer. 2010; 8

5Altan M et al. Clin Cancer Res. 2017; 6Yonesaka K et al. Clin Cancer Res. 2018.

Summarizing AKY-2519 (B7-H3) development to date

Generated from Aktis' platform, AKY-2519 (B7-H3) has demonstrated promising in vivo results including survival benefit

48hr

ST1273R (mCRPC PDX)

1500

1250

1000

750

Vehicle

[225Ac]Ac-AKY-3212 (1.0 µCi)

[225Ac]Ac-AKY-3212 (2.0 µCi)

[177Lu]Lu-PSMA-617 (810 µCi)

500

250

0 ***

0 3 6 9 12 15 18 21 24 27 30 33

Study Day

AKY-2519 tool compound, AKY-3212, has shown superior efficacy compared to PSMA-617 in an mCRPC mouse model

Tumor uptake at 4h

[177Lu]Lu-PSMA-617 [225Ac]Ac-AKY-3212

Tumor volume (mm3)

%ID/g

PDX=patient-derived xenograft mouse model. 9

AKY-2519, a novel B7-H3-targeted radioconjugate, and its biodistribution profile in patients with mCRPC*

Date and Time: May 30, 1:30 p.m. - 4:30 p.m. CDT

Clinical imaging and dosimetry data for AKY-2519 to be presented at the 2026 ASCO Annual Meeting

Data at ASCO will highlight biodistribution and uptake of AKY-2519 in tumors and normal tissue in patients with mCRPC and other solid tumors

First-in-human PET/CT imaging with 68Ga-AKY-2519, a B7-H3 targeted miniprotein radioconjugate, to demonstrate tumor uptake and normal tissue exposure across various advanced solid tumors**

Date and Time: May 30, 1:30 p.m. - 4:30 p.m. CDT

*This normal tissue biodistribution and tumor uptake assessment through PET/CT imaging and normal tissues and tumor dosimetry analyses through sequential SPECT/CT imaging of patients with mCRPC was conducted at the

Nuclear Medicine Research Infrastructure (NuMeRI), University of Pretoria and Steve Biko Academic Hospital, South Africa. 10

**This normal tissue biodistribution and tumor uptake assessment through PET/CT imaging in various solid tumors was conducted at the Department of Nuclear Medicine, University of Duisburg-Essen and German Cancer

Consortium (DKTK), Universitätsklinikum Essen (University Hospital Essen), Essen, Germany.

Significant opportunity for B7-H3 as a differentiated radiopharmaceutical target in mCRPC and other indications

B7-H3 is highly expressed in multiple solid tumors; Potential to unlock whitespace opportunities

PLUVICTO® estimated global peak sales ~$5.4 billion in prostate cancer alone1

Persistent unmet needs remain due to:

PSMA downregulation or PSMA-low expression

Aggressive/ poorly differentiated cancer with PSMA expression loss

PSMA expression in the salivary glands

90% of mCRPC patients express B7-H3

Low expression in normal tissues, including salivary glands

B7-H3 targeting RLT has the potential for differentiated

biodistribution compared to PSMA-targeted therapies

Prostate

Indication

Metastatic incidence in US2

Initial Positioning

B7-H3

expression positive3

Prostate cancer

~23.9k

2L+

90%

NSCLC

~99.7k

2L+

80%

SCLC

~22.9k

2L+

70%

PSMA

Up to

24K

addressed

SCLC

Prostate

B7-H3

Up to

215K

addressed

NSCLC

Pancreatic

Source: Company filings, LEK research, CADTH reports, research papers, World Cancer Research Fund, American Society of Clinical Oncology, American Cancer Society; Datamonitor; SEER database.

1 Wall Street consensus estimate; 2GLOBOCAN and Aktis analysis; 3 Based on internal IHC analysis. 11

Note: Expression prevalence is not accounted for in each of the targets.

Utilizes prostate cancer-specific RLT centers

•

Enables mCRPC-targeted dose finding and expansion

as well as characterization of B7-H3 expression vs.

PSMA expression

•

Enables generation of data in both PLUVICTO-naïve

and PLUVICTO-experienced patients to inform sequencing decisions

Anticipated advantages of a dedicated mCRPC clinical trial protocol

Radiopharmaceuticals

are a key treatment modality for prostate cancer

Significant enthusiasm

among prostate cancer investigators for early AKY-2519 data

mCRPC-dedicated Phase 1b trial designed to rapidly generate data in PLUVICTO-naïve and -experienced patients

AKY-2519-01 Trial design

6 MBq

9 MBq

12 MBq

THERAPY

Backfill Dose 1

[225Ac]Ac-AKY-2519

PLUVICTO-

experienced

6 MBq

9 MBq

12 MBq

THERAPY

Backfill Dose 2 PLUVICTO-naïve

[225Ac]Ac-AKY-2519

THERAPY

[225Ac]Ac-AKY-2519

Cohort A PLUVICTO-naïve

THERAPY

Backfill Dose 1 PLUVICTO-naïve

[225Ac]Ac-AKY-2519

Dose escalation: BOIN Backfill (n≈30/cohort; escalation pts included)

Dose levels for backfill may be different based on cohort

THERAPY

Backfill Dose 2

[225Ac]Ac-AKY-2519

PLUVICTO-

experienced

THERAPY

[225Ac]Ac-AKY-2519

Cohort B PLUVICTO-experienced

All patients entering the study will have demonstrated tumor uptake following imaging with [64Cu]Cu-AKY-2519

BOIN=Bayesian Optimal Interval. 13

Positioning AKY-2519 to demonstrate its broad potential to address unmet patient needs

B7-H3 highly expressed in multiple solid tumors across large patient populations

Represent whitespace opportunities in radiopharmaceuticals

Initiated mCRPC-dedicated Ph1b trial in PLUVICTO-naïve and -experienced patients

Expect to start Ph1b basket trial in 2H'26

Preliminary data from Ph1b mCRPC trial expected in 2027

Multiple anticipated catalysts over the next 12 months

2026

2027

AKY-2519 (B7-H3)

MAY'26

mCRPC

Ph1b trial

MAY'26

Clinical imaging and

dosimetry data - ASCO

2H'26

Basket Ph1b trial start

2027

Prelim data from Ph1b mCRPC trial in 2027

AKY-1189 (Nectin-4)

1Q'27

Ph1b prelim data in

1Q'27

Corporate

2H'26

Aktis GMP manufacturing

suite operational

1Q'27

Two new clinical candidates

Disclaimer

Aktis Oncology Inc. published this content on May 05, 2026, and is solely responsible for the information contained herein. Distributed via Public Technologies (PUBT), unedited and unaltered, on May 05, 2026 at 12:10 UTC.