ADC conjugation tech firm Ambrx looks to raise $86m in IPO

The firm, who has ongoing collaborations to develop antibody-drug conjugates (ADCs) with biopharma firms including Bristol-Myers Squibb, Merck & Co. and Agensys, filed a Form-S1 Statement of Registration with the SEC on Friday.

The firm licenses both its bacterial platform ReCODE and ADC generating mammalian platform, EuCODE, but also uses the platforms in developing its own pipeline, for which it is trying to raise the money.

Ambrx said in the filing: “We will require additional capital for the further development and commercialization of our product candidates, and cannot be certain that additional funding will be available on acceptable terms, or at all.”​

Ambrx’ lead ADC candidate is its HER2+ breast cancer drug which has entered the preclinical stage, though the firm also has a long-acting protein product for growth hormone deficiency in Phase II trials.

BMS licensed Ambrx’ bio-conjugation technology last May​ to be used with its antibodies, payloads and targets, on top of two other collaboration agreements for diabetes and heart failure products.

Bio-Conjugation​

As biopharma continues to focus on ADCs as a next generation cancer drug, the firm says its IP conjugation technology overcomes the limitations of earlier generation bio-conjugates.

This is done, the firm says, by applying its protein medicinal chemistry to consistently attach its proprietary linkers, payloads and half-life extenders to proteins at specific sites and create a homogeneous drug product.

“We can then test this drug product for pharmaceutical characteristics and physiological effects to develop a more precise understanding of how conjugating at different locations affects the activity of a drug,” ​the firm said in the filing.

This enables a wider therapeutic index which allows a higher dosage to increase the pharmacological effect with a similar safety profile or a lower dosage that achieves the same pharmacological effect with an improved safety profile.