Science of Radiopharmaceuticals

Unlocking new possibilities in cancer drug development

What is a radiopharmaceutical?

Radiopharmaceuticals consist of a cancer-targeting binding moiety linked to a radioactive payload. The binding moiety can be a peptide, small molecule, or biologic that has high affinity for extracellular tumor markers that are overexpressed on cancer cells.

Once administered, the radiopharmaceutical travels throughout the body and specifically binds to tumor cells, where the radioactive payload decays and induces DNA damage in the cancer cells.

Different payloads are used for imaging and therapy. For therapeutic purposes, Alpha-9 uses alpha- and beta-emitting isotopes (e.g., ¹⁷⁷Lu and ²²⁵Ac). Beta-emitters cause single-stranded DNA breaks while alpha-emitters cause double-stranded DNA breaks.

Accelerating cancer drug development

Radiopharmaceuticals provide transformational outcomes, demonstrating impressive efficacy and safety in patients where multiple lines of treatment have failed.

Radiopharmaceutical development offers distinct advantages, allowing Alpha-9 to move from bench to bedside rapidly and cost-effectively. Early human studies de-risk clinical development by validating target engagement and robust payload delivery to tumor sites. Our production expertise similarly enables efficient clinical translation and scale-up.

With the commercial launch of multiple radiopharmaceuticals, hundreds of clinical sites globally are equipped to work with ¹⁷⁷Lu and ²²⁵Ac therapies. Alpha-9 leverages these established networks to accelerate patient recruitment and trial execution. Alpha-9’s early clinical development process focuses on two key components:

Imaging:

Where is the molecule?

Imaging studies reveal whether a molecule demonstrates tumor-specific uptake while also identifying off-target accumulation sites. The molecule “lights up” tumor tissue on PET/SPECT scans.

Therapy:

Is the molecule safe and efficacious?

After the imaging study, patients who have sufficient target expression can enroll in a therapeutic study. From the therapeutic molecules, Alpha-9 measures whether sufficient radiation payload is delivered to kill tumor cells while sparing healthy tissue. The overall safety and efficacy profile can be seen in just a few doses.