RayzeBio, a company specializing in radiopharmaceuticals, nets $160 million in Series D funding

BIOTECH: Reimagining Radiopharma

RayzeBio is reimagining the role of radiopharmaceuticals in oncology. “Targeted radiopharmaceutical therapy is about taking the power of radiation and delivering it in a much more directed way,” said RayzeBio President and CEO Ken Song, M.D.

San Diego-based RayzeBio's lead product candidate, RYZ101, is a targeted radiopharmaceutical drug designed to deliver Actinium-225 (Ac225), a highly potent alpha-emitting radioisotope, to solid tumors.

“[Ac225's] radiation is not orders of magnitude, it's probably millions of orders of magnitude, if not billions of orders of magnitude more potent as a

payload than a chemotherapeutic agent,” Song said.

Despite the higher potency of RYZ101, previous data show alpha particles offer greater efficacy and a better safety profile than traditional chemotherapy. RayzeBio's “much more elegant” delivery mechanism also adds to its safety and efficacy.

One of the biggest drawbacks to chemotherapy has always been that it only works on a spall subset of patients. RayzeBio's therapeutic model uses an imaging isotope attached to a drug binder and injected into the body of a patient, allowing doctors to screen out patients that the treatment would be ineffective on.

“This idea of precision medicine, which people have talked about since the '90s, there's probably nothing better that exemplifies precision medicine than radiopharmaceuticals because you can actually image every patient with your drug binder as an imaging agent first to verify that the patient's cancer is actually taking up the drug before you treat them.”

An Industry First

RYZ101 is positioned to be the first approved Ac225 radiopharmaceutical therapy for the industry.

The drug candidate is currently enrolling patients in the Phase 1b and Phase 3 trials, testing its safety, tolerability and pharmacokinetics. RayzeBio expects to announce data from the trial in 2023.

Additionally, RayzeBio received Investigational New Drug Application (IND) clearance from the U.S.D.A. to investigate RYZ101 for first-line treatment of patients with SSTR+ extensive-stage small cell lung cance in combination with standard of care.

“We believe RYZ101 has strong scientific rationale for treatment of both GEP-NETs and small cell lung cancer. We are very encouraged with the level of interest we have seen in the program and look forward to reporting results from RYZ101 in due course” said Susan Moran, M.D., chief medical officer of RayzeBio. “Clinicians and patients are very excited about the mechanism of action of RYZ101 and the advantages it offers. Significant interest is growing to explore Ac225, a highly potent radioisotope, for treatment of solid tumors.”

Attracting Investment

RayzeBio's radiopharmaceutical model has garnered significant interest from investors.

On Sept. 13, Rayze Bio announced a $160 million Series D financing co-led by Viking Global Investors, Sofinnova Investments and Wellington Management. Additional new investors Ally Bridge Group, Sands Capital, Laurion Capital Management, Soleus Capital, and an undisclosed global investor also participated, as did RayzeBio's current investors.

RayzeBio has now raised $418 million since beginning operations in August 2020.

“RayzeBio has accelerated innovation in the emerging field of targeted radiopharmaceuticals and is breaking ground with Actinium-225 based drugs. We are thrilled to partner with Ken, the management team and board to drive these exciting and potentially game-changing treatments to cancer patients,” said Maha Katabi, Ph.D., managing partner at Sofinnova Investments who is joining the RayzeBio Board of Directors in connection with the Series D.

In addition to advancing RYZ101 into the clinic, RayzeBio has built a state-ofthe-art 28,000-square-foot R&D facility in San Diego.

The company also invested in securing key aspects of commercial scale manufacturing and radioisotope supply.

“We purposely made investments, not just in discovery and not just in doing the clinical studies, but because this a new sector we believe is going to explode over the next several years, we've also made direct investments in manufacturing,” Song said. “In the last two years, we have transformed from an early start-up to an integrated radiopharmaceutical company leading innovation with this modality to fight cancer.”

RayzeBio over the last two years has completed more than 200 in vivo studies to discover novel drug candidates and entered into a licensing agreement with Ablaze Pharmaceuticals, a biotechnology company that is focused on development and commercialization of radiopharmaceuticals for China.„