Mythic Therapeutics Scores $103 Million to Make "Safer and Smarter" ADCs

Mythic Therapeutics has roared out of the gate with a $103 million oversubscribed Series B financing round that will support the development of a next generation of antibody-drug conjugates (ADCs) that the newly-launched company says will be “safer and smarter.”

ADCs are an increasingly popular therapeutic approach to treating cancer. They work by pairing antibodies with toxic agents and precisely pinpointing cancer tumors. When the ADCs hit the specific tumor target, they release cytotoxins that deliver thousands of times more potent than chemotherapy. The toxins target the tumor and not the healthy cells surrounding it.

There are currently 11 approved ADCs on the market in the United States, with eight of these greenlit since 2017. The market has been predicted to grow to about $2.6 billion this year. Companies leading in this space include pharma giants Bayer and Roche, as well as Concortis Biotherapeutics, Immunomedics, and others.

ADCs currently on the market include AstraZeneca’s Enhertu, a treatment for patients with unresectable or metastatic HER2-positive breast cancer; Padcev, a first-of-its-kind treatment for metastatic urothelial bladder cancer developed by Astellas and Seattle Genetics; and Genentech’s Polivy, and ADC for people with diffuse large B-cell lymphoma whose disease returned after or did not respond to multiple treatment regimens.

While multiple companies are assessing ADCs, newly-launched Mythic noted that the clinical benefit of ADCs has remained limited to a subset of diseases, particularly those that have high levels of target expressions. However, Mythic believes that its FateControl technology can dramatically improve the therapeutic index of ADCs, independent of the linker and payload. The company said its approach could expand the role of ADCs in precision medicine against a broad set of molecular targets and patient profiles.

Brian Fiske, Ph.D., co-founder and chief scientific officer of Mythic Therapeutics, said that to date, ADC improvements have primarily been focused on innovations in linker and payload chemistries, conjugation technology, and new target biology.

“Mythic seeks to improve the clinical performance of ADCs by introducing a new dimension of ADC technology focused on manipulating the fate of ADCs within the cell,” Fiske said in a statement.

ADCs deliver a therapeutic payload to a specific target tissue or disease site. However, there have been concerns about the non-specificity of the delivery, meaning, the effect could be diminished and lead to toxicity issues. Pointing to its FateControl technology, Mythic said it could increase the amount of ADC that is “internalized by the target tissue” while at the same time reducing payload release in non-targeted tissues. That would mean that Mythic’s approach could be safer and more productive than existing ADCs.

Mythic’s lead program is in lung cancer, and it said the FateControl technology “has the potential to drive a multi-fold expansion of the number of lung cancer patients eligible for treatment using ADCs.” The proceeds from Mythic’s Series B will be used to drive the lead program through first-in-human clinical studies in lung cancer and fund pipeline development. The company plans on developing a pipeline of products incorporating its platform technology.

The Series B was led by Viking Global Investors and was supported by Venrock Healthcare. Capital Partners, Foresite Capital, Perceptive Advisors, and Highside Capital. Existing Mythic investors participating in the round include First Round Capital, OMX Ventures, Lifeforce Capital, and Refactor Capital.

“We are thrilled to partner with this distinguished group of investors,” Alex Nichols, co-founder, president and chief executive officer of Mythic Therapeutics said in a statement. “This financing validates the FateControl approach and supports our efforts to achieve expanded use of Mythic’s ADCs within and across indications, translating to improved outcomes for patients with unmet medical needs.”