With crossover round in its pocket, synthetic lethality-focused Cyteir Therapeutics eyes a jump onto Nasdaq
Cyteir Therapeutics CEO Markus Renschler has his eye on the market. The Celgene vet pulled in an $80 million crossover round on Thursday to fuel Cyteir’s lead synthetic lethality program, and when the time is right, he’ll have the S-1 ready.
“We’re considering an IPO in 2021,” Renschler said, adding that the timing isn’t set in stone.
Until then, the Series C should give Cyteir the flexibility to grow its team, and advance its lead candidate — an inhibitor of RAD51-mediated DNA repair dubbed CYT-0851 — to Phase II as a monotherapy. The small biotech is also planning combination trials that pair CYT-0851 with other cancer treatments, like chemotherapies and potentially PARP inhibitors.
The idea behind synthetic lethality is to inhibit the DNA damage repair that cancer cells need to survive and grow, Renschler explained. Much like Covid is mutating, cancers mutate to become more aggressive, avoid chemotherapy and so forth, he said. That genomic instability creates “breaks” that must be repaired.
What sets Cyteir apart from others pursuing synthetic lethality, Renschler said, is that CYT-0851 targets RAD51, a critical enzyme in double-stranded DNA repair. Jackson Laboratory researcher Kevin Mills, Cyteir’s former CSO, discovered RAD51 plays a vital supporting role in cell repair in cells that highly express a molecule called activation-induced cytidine deaminase — a benign enzyme in normal cells that becomes hyperactive and damages DNA in cancer cells.
“It is absolutely essential to repair that damage, and we have shown by selecting cancers, or patients that have cancers that have high degrees of these double stranded breaks, we can have an impact on their cancer growth,” Renschler said.
CYT-0851 is currently in the dose-escalation portion of a Phase I/II study for solid tumors and hematological malignancies, and is slated to enter Phase II in the second half of this year.
In combination with other chemotherapies or PARP inhibitors, it could act as a “synergistic double punch,” Renschler said. The other drug would induce DNA damage, while the RAD51 inhibitor would inhibit the repair.
Some of the Series C money will finance IND-enabling studies for CYT-1853, what Renschler called the company’s “second-generation” RAD51 inhibitor. Cyteir also has an undisclosed compound for solid tumors up its sleeve, for which it plans to launch IND-enabling studies in 2023.
In addition, the 25-person company says it’s looking to double its head count this year.
The synthetic lethality space has been heating up. Anticancer Bioscience launched earlier this week with $21 million from private Chinese investors to stand shoulder to shoulder with US synthetic lethality players like Repare, Artios, Ideaya and Cyteir. Back in June, GlaxoSmithKline R&D chief Hal Barron fronted $120 million cash to partner with Ideaya, promising another $940 million to $960 million in combined development and regulatory milestones for each product to successfully emerge onto the market.
RA Capital Management led Cyteir’s Series C with Janus Henderson Investors, Acuta Capital Partners, Ally Bridge Group, Avidity Partners, Ample Plus Fund, and CaaS Capital Management. Novo Holdings, Venrock, Lightstone Ventures, DROIA Ventures, Osage University Partners (OUP), and other undisclosed investors chipped in.
A correction has been made to Kevin Mills’ title, and the spelling of CYT-0851 on second reference.