Plus Therapeutics, Inc. Q4 FY2023 earnings call

Clinical and Regulatory Progress - The ReSPECT-LM Phase 1/2 dose escalation trial of rhenium obisbemeda for LM shows positive safety and efficacy signals, with enrollment on track to finish by year-end 2024. - Acquired a cerebrospinal fluid tumor cell testing technology in September 2023, and it has been successfully implemented in the ReSPECT-LM trial. - The ReSPECT-GBM trial for recurrent glioblastoma continues enrolling, with plans to expand trial sites in 2024. - Anticipate presenting interim safety and feasibility data from the ReSPECT-LM trial at the SNO/ASCO CNS Cancer Conference in August 2024 and updating the full Phase 1 at the SNO Annual Meeting in November 2024. ### Supply Chain and Pipeline - Working to build out GMP manufacturing relationships for rhenium obisbemeda to support commercial demand. - Focusing on two areas: development of the next-generation radioembolic device RNL BAM and obtaining nondilutive grant funding.

As of December 31, 2023, cash and cash equivalents were $8.6 million compared to $18.1 million as of December 31, 2022. The company recognized $4.9 million of grant revenue during the year ended December 31, 2023 compared to $0.2 million in 2022. The net loss decreased by $6.9 million from $20.3 million in the year ended December 31, 2022, to $13.3 million in the year ended December 31, 2023.

Key Milestones - Safety and efficacy data from the Phase 1 ReSPECT-LM trial will be presented at the SNO/ASCO CNS meeting in August 2024 and further updated at the SNO meeting in 2024. - Anticipate completing the Phase 1 LM trial by the end of 2024 and developing a Phase 2/3 pivotal trial design for breast cancer patients with LM in conjunction with the FDA. - Expand GBM trial sites, complete enrollment in the Phase 2 trial by late 2024 or early 2025, and finalize pivotal trial design planning with the FDA. - Pending IND clearance from the FDA, initiate the Phase 1 pediatric brain cancer trial. - Bolster the rhenium obisbemeda supply chain and complete device development milestones for RNL BAM in 2024.

Q: Could you provide some more color on the current availability of rhenium-186 and what it will take to scale up and meet potential clinical and then commercial demand?

A: Marc Hedrick stated that in the near-to-intermediate term, they can scale from current providers, need additional GMP manufacturers, and are working on increasing radiation services provider and building up backup supply agreements.

Q: You'd mentioned that you're still evaluating the long-term commercial potential of the CN side assay. I was just wondering if you'd share any initial thoughts about potential clinical utility of the assay outside of or, in addition to rhenium obisbemeda?

A: Marc Hedrick said the assay has value in improving diagnosis, expanding market size, and potential for disease management and as a surrogate biomarker.

Q: For the CNS side assay, will we start seeing more results based on that from cohort 4 of the LM study?

A: Marc Hedrick said the test is up and running, and data from cohort 5 will be seen.

Q: For the potential future pivotal study that's coming next year, do you see CNS side serving as a primary endpoint?

A: Norman LaFrance said it's likely a secondary or exploratory endpoint currently, with data driving future decisions.

Q: You mentioned that you guys were going to look for $10 million of grant proposals this year on top of $7 million last year. What are you seeing in terms of the landscape for grant opportunities out there?

A: Marc Hedrick said grants are hard to get, but they have an advantage with unmet medical needs and a good relationship with CPRIT.

Q: What is the status of the pediatric trial? And when do you expect to start treating patients?

A: Norman LaFrance said they've been to FDA, will submit final IND, expect to enroll first patients by second half of 2024 with pediatric site preparation underway.