PSTV

• In early March, an underwritten equity financing of $15 million in gross proceeds and $2 million in accelerated grant proceeds from CPRIT. Strengthened balance sheet and funding through key milestones into mid-2026. • Strengthened senior leadership team: Dr. Mike Rosol as Chief Development Officer, Mr. Russ Bradley as President and General Manager of CNSide, Dr. Jonathan Stein as Medical Director at CNSide. • REYOBIQ updates: FDA-accepted proprietary name, orphan designation for LM due to lung cancer, fast-track designation, and progress in clinical trials for glioblastoma, leptomeningeal cancer, and pediatric brain cancer. • ReSPECT-LM Phase 1 single administration dose escalation trial completed, recommended Phase 2 dose of 44 millicuries determined. Plan to conduct dose expansion trial and multiple dose escalation trial. • Glioblastoma Phase 1 trial results published in Nature Communications, Phase 2 trial ongoing. Pediatric brain cancer program received $3 million DOD grant, anticipating IND approval in 2025. • Partnerships in radiotherapeutic drug production and supply chain management, expanding for redundancy. • CNSide as CNS cancer testing platform, hiring team, establishing lab, ongoing market access activities, plan to launch fully in 2025.

• Anticipate FDA meeting for REYOBIQ to align on registrational trial path for single dose in breast cancer LM. • 2025 grant revenue expected $6M-$8M. • On track to initiate ReSPECT-LM Phase 1 multiple dose escalation trial, complete first cohort of multiple doses. • Meet with FDA to agree on clinical development plan for REYOBIQ. • Complete enrollment of final patients in ReSPECT GBM Phase 2 trial by end of year. • Obtain IND approval for ReSPECT PBC Phase 1 trial and start enrollment. • CNSide on track to launch fully in 2025 with geographically limited introduction expanding over the year, market access activities ongoing, financial guidance to begin later in year.

Cash and investments balance was $3.6 million at December 31, 2024, compared to $8.6 million at December 31, 2023. Grant revenue in 2024 was $5.8 million, compared to $4.9 million in 2023. Expected 2025 grant revenue is in the range of $6 million to $8 million. Total operating loss in 2024 was $14.7 million, net loss was $13 million or $1.95 per share compared to $13.3 million or $4.24 per share in 2023.

• Forward-looking statements subject to risks and uncertainties described in Form 10-K and 10-Q. • Regulatory uncertainties in clinical trial approvals and market access for CNSide. • Supply chain risks related to radiotherapeutic drug production and commercialization. • Uncertainties in achieving clinical trial milestones and FDA meeting outcomes.

Q: On the CNSide, do you anticipate building up a major sales force or will you look for partners to commercialize this?

A: Not a major sales force; starting with academic neuro-oncologists at major oncology centers, may consider partnering later.

Q: The recurrent GBM trial is the most advanced. Are you able to lay out what must happen to meet the goal of data this year?

A: Enrolling remaining patients, focusing on adding new sites, with 11 patients needed to complete Phase 2, achievable with current sites.

Q: On the LM study, is the dose expansion going to be another additional cohort to the Phase 1 study or part of Phase 2?

A: Anticipate FDA discussion on Phase 2 trial design for breast cancer LM, possibly with 30 patients (15 of each hormonal subtype), could roll into approval trial; could also do Phase 1b but less expedient for regulatory approval.

Q: With regards to the multi-dose study, would you wait for first data to come out before initiating Phase 2 or build into Phase 2?

A: Moving forward directly into Phase 2 or 1b, multiple dose data important for PK/PD and trial design, single dose approval promising and to be pursued quickly.