Femtogenix Presents Novel Data on Antibody Drug Conjugates Containing Reduced Potency Payloads in Solid Tumour Models

Femtogenix Ltd, a UK biotechnology company developing the next generation of DNA-interactive Antibody Drug Conjugate (ADC) payloads, today announced data demonstrating the potent efficacy and favourable toxicity profile of a reduced potency analogue from its Pyridinobenzodiazepine (PDD) ADC payload platform in solid tumour models. The data is being presented at AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics, Boston,USA.

Within its PDD platform, Femtogenix has developed a lower potency DNA mono-alkylator with superior in vivo properties to other DNA alkylating agents, illustrating a promising new approach in the development of ADCs for difficult-to-treat tumours. When attached to antibodies or other targeting moieties, Femtogenix's novel PDD payload platform allows reversible/irreversible DNA minor groove binding, in a sequence-interactive manner, leading to highly targeted cytoxicity towards tumour cells. The payloads are designed to have a novel mechanism of action and IP space compared to existing DNA-interactive payloads, to have minimal hydrophobicity and to be resistant to P-Glycoprotein pumps in tumour cells.

These new data demonstrate that Femtogenix's reduced potency payload has a favourable toxicity profile in rats, potent in vivo efficacy (MED < 1 mg/kg), and improved tolerability (i.e., MTD of 40 mg/kg) in solid tumour models when conjugated to antibodies.¹ Its toxicity profile and wide therapeutic window is coupled with the ability to increase drug-antibody ratio (DAR) beyond the traditional limit of two, for increased conjugation to antibodies.

Professor David Thurston, Chief Scientific Officer, commented: "The favourable hydrophobicity profile of the low potency mono-alkylator and its ease of conjugation, along with the significant in vivo efficacy and tolerability of the ADCs produced, suggest that this payload represents a promising new approach in ADC development, specifically for the treatment of solid tumour malignancies."

Femtogenix has generated extensive data on mechanism of action (MOA) of the ADC payload, illustrating a primary MOA of DNA alkylation, coupled with an ability to inhibit transcription factors. The molecules have been designed through proprietary molecular modeling methodologies to maximise interaction within the DNA minor groove. Payloads with differing potencies and modes of action may be suitable for particular uses or specific target situations.

1. Dr Nicolas Veillard, PhD, Team Leader, Femtogenix: ?A new low potency DNA guanine monoalkylating ADC payload with enhanced in vivo tolerability' (C030), poster session C 12:30?4:00pm, 29 October 2019, AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics

This announcement follows data presented earlier this month at World ADC 2019, San Diego, verifying the favourable toxicity profile and potent efficacy of its Pyridinobenzodiazepine (PDD) ADC payload platform in tumour cell models. Read the press release here.