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Bonum Therapeutics

Cytokine therapies that switch on only at their target

Raised to date

$26.9M

of $32.3M offered across 1 Form D filing

Still open
$5.4M
Investors
8
Last filed
Apr 17, 2026

About

Bonum Therapeutics is a Seattle biotechnology company developing a new class of regulated protein therapeutics that deliver potent biological activity only where it is needed. Its dual-binding antibodies carry engineered sensor domains that keep an attached therapeutic — initially a cytokine — switched off until the molecule engages its target, and switch it back off if it disengages. The company was formed in 2021 by the team from Good Therapeutics after Roche acquired that company's PD-1-regulated IL-2 program in 2022. Oncology is its first therapeutic area, with the platform also applicable to autoimmunity, metabolic disease, and pain.

Regulation is reversible and target-engagement driven rather than protease dependent, so the therapeutic deactivates again if the molecule leaves its target — and the sensor domains can be engineered against peptides, proteins, or metabolites, giving broad targeting flexibility with lower systemic toxicity.

Funding

  • EquityFiled Apr 17, 2026Form D
    $26.9M/ $32.3M

Product

Regulated protein therapeutics platform

Biopharmaceutical discovery platform

A drug discovery platform built on dual-binding antibodies with sensor domains that act as molecular switches: the attached therapeutic payload stays inactive until the antibody binds its target, and reverts to inactive on disengagement. Bonum's lead application is regulated cytokine therapeutics designed to drive anti-tumor immune responses in the tumor microenvironment.

  • Sensor domains that gate therapeutic activity on target engagement
  • Reversible regulation rather than irreversible protease-dependent activation
  • Sensor domains engineerable against peptides, proteins, or metabolites

Built for

Cancer patients, reached via pharmaceutical partners and licensees who develop and commercialize the resulting therapeutics

People on file