PSTV 10-Q: Smart Summary

• Business description: Plus Therapeutics, Inc. is a U.S. healthcare company developing precision diagnostics and targeted radiopharmaceuticals for CNS cancers; its wholly owned subsidiary CNSide Diagnostics, LLC develops and commercializes proprietary laboratory-developed tests including CNSide®, while its lead radiopharmaceutical candidate is rhenium (186Re) obisbemeda (targeting recurrent GBM, LM, and PBC), and its acquired candidate 188RNL-BAM is designed to treat primary and secondary liver cancers by intra-arterial injection.
• Reverse stock split: The Board fixed the reverse stock split ratio at 1-for-25 on March 20, 2026; the Certificate of Amendment was filed April 1, 2026 and became effective April 2, 2026, converting approximately 171,550,698 shares to approximately 6,862,027 shares with no change to the $0.001 par value, no fractional shares issued, and no modification to voting rights.
• Retroactive restatement: All share counts, stock-based awards, warrants, and equity incentive plan figures in the financial statements have been proportionally and retroactively adjusted to reflect the 1-for-25 Reverse Stock Split for all periods presented.

• Diagnostic revenue recognition: The Company began commercial billing for diagnostic revenue during the three months ended March 31, 2026, recognizing revenue under ASC 606 at the point in time a completed test report is delivered to the ordering healthcare provider; the estimated net revenue amount was immaterial for recognition in the statement of operations. Transaction price reflects estimated contractual adjustments and implicit price concessions (recorded as a reduction of revenue, not bad debt expense), with variable consideration constrained so that revenue is recognized only to the extent a significant reversal is not probable.
• Grant revenue: Government grants are outside the scope of ASC 606 (funders do not meet the 'customer' definition); the Company applies IAS 20 by analogy and recognizes revenue as allowable expenses are incurred. Deferred grant liability represents funds received or receivable for which allowable expenses have not yet been incurred; grant receivable represents funds not yet received for which expenses have been incurred.
• Warrant classification: Warrants are classified as either equity or derivative liabilities under ASC 815; liability-classified warrants are remeasured to fair value each reporting period with changes recognized in the statements of operations, while equity-classified warrants are recorded in additional paid-in capital at issuance and not subsequently remeasured.
• Upcoming pronouncement: ASU 2024-03 (expense disaggregation disclosures) is effective for annual periods beginning January 1, 2027 and interim periods beginning January 1, 2028; the Company is analyzing its impact on disclosures.

• Going concern: The Company has substantial doubt about its ability to continue as a going concern, driven by an ongoing need to raise additional cash from outside sources to fund future clinical development programs, launch the CNSide Test, and fund other operations, with no assurance that additional capital can be raised; failure to raise sufficient capital would require the Company to at minimum significantly reduce or curtail its research and development and other operations.
• Nasdaq Minimum Stockholders' Equity: The Company is currently in compliance with Nasdaq Listing Rule 5550(b)(1) but is subject to monitoring through August 22, 2026; if the Staff determines the Company no longer satisfies the Minimum Stockholders' Equity Requirement during that period, the Staff will issue a delist determination letter with no opportunity to submit a plan of compliance or cure period, and the Company would have an opportunity to request a new hearing before the Nasdaq Hearings Panel.
• Nasdaq Minimum Bid Requirement: On April 20, 2026, the Company received written notice from The Nasdaq Stock Market LLC that it had regained compliance with the Minimum Bid Requirement following implementation of a Reverse Stock Split, which became effective on April 2, 2026.

• Financial assets at fair value: All financial assets — money market accounts and treasury bills/government bonds classified as cash equivalents or investments — are measured at Level 1, with fair values known through observable market prices. As of March 31, 2026, cash equivalents consisted of money market funds totaling $2.8M; investments included treasury bills of $9.6M and government bonds of $2.5M (total investments $12.1M). As of December 31, 2025, cash equivalents totaled $8.5M (money market $1.5M plus treasury bills $7M); investments totaled $4.4M (treasury bills $2.9M plus government agency bonds $1.5M). No Level 3 assets exist and no transfers between levels occurred during the three months ended March 31, 2026.
• Convertible notes (Level 3, Q1 2025 only): Funding Notes and Exchange Notes issued February 13, 2025 were valued using the binomial lattice model; at issuance, key inputs were interest rate 4.18%–4.28%, volatility 77.5%, and common stock fair value $1.20; at settlement (March 4, 2025), interest rate 3.99%, volatility 119.2%, common stock fair value $0.30. Funding Notes were issued at $4M, changed in fair value by ($265,000, and settled at ($3.7M; Exchange Notes were issued at $3.8M, changed in fair value by ($251,000, and settled at ($3.5M — both ending at $0 as of March 31, 2025.
• Warrant liabilities (Level 3, Q1 2025): February 2025 Warrants (Black-Scholes, volatility 98.5%–102.1%) were issued at $2.8M and settled at ($531,000, ending at $0. March 2025 Series A and Series B Warrants (Monte Carlo, volatility 123.7%) were issued at $2M and $11.2M respectively; after fair value changes of $3.1M and $8.8M respectively, the ending balances as of March 31, 2025 were $5.1M (Series A) and $20.1M (Series B), for a combined warrant liability total of $25.1M.
• Investor liability (Level 3): A repayment obligation to March 2025 Private Placement Purchasers carried a liability of approximately $4.5M as of December 31, 2025; during the three months ended March 31, 2026, the Company paid $4.5M to fully extinguish the liability, 272,821 shares were returned and cancelled, and the associated restriction on $4.5M of restricted cash and cash equivalents lapsed. No impairment was recorded on long-lived assets, intangible assets, or goodwill during the three months ended March 31, 2026 and 2025.

• Classification: All short-term investments are classified as available-for-sale securities; investments with maturities longer than three months from purchase date are classified as short-term investments in the condensed consolidated balance sheets, reflecting management's intent and ability to use these assets to meet current operations' liquidity requirements.
• Unrealized gains: Unrealized gains on available-for-sale securities were immaterial for the three months ended March 31, 2026 and 2025, and not presented separately in the condensed consolidated statements of operations.
• Maturity profile: As of March 31, 2026, total investments had an amortized cost and estimated fair value of $12.1M, with $9.6M due in one year or less and $2.5M due after five years; no investments were held in the one-to-five-year bucket.

Anti-dilutive instruments: The company reported a net loss in both periods presented, rendering all potentially dilutive instruments anti-dilutive; total excluded shares were 2,802,045 as of March 31, 2026 vs. 177,562 as of March 31, 2025, with the increase driven primarily by outstanding warrants (1,941,456 vs. 125,679) and the addition of 253,042 restricted stock units in 2026 (none in 2025). February 2025 Warrants, Funding Notes, and Exchange Notes: Shares underlying these instruments, each outstanding during the three months ended March 31, 2025, were also excluded from diluted loss per share as their effect would be anti-dilutive. Pre-funded warrants: Pre-funded warrants are included in weighted average shares outstanding for both basic and diluted EPS calculations (as of the beginning of the period or date of grant, whichever is earlier) given their nominal exercise price.

• CPRIT Grant revenue: The Company recognized $1M in grant revenue from the CPRIT Contract during the three months ended March 31, 2026, compared to $1.1M in the three months ended March 31, 2025; the grant revenue receivable related to the CPRIT Grant was $1.4M as of March 31, 2026 versus $300,000 as of December 31, 2025.
• CPRIT contract terms: The CPRIT Contract runs through August 28, 2026 and carries a matching fund requirement (one dollar for every two dollars awarded by CPRIT), revenue sharing obligations upon commercialization based on specific dollar thresholds and tiered low single digit royalty rates until CPRIT receives 400% of the proceeds awarded, and a potential repayment obligation (with interest not to exceed 5% annually) upon certain early termination events or relocation of the Company's principal place of business outside of Texas.
• DoD Award: Effective September 1, 2024, the Company entered into a $3M award from the Department of Defense office of the Congressionally Directed Medical Research Programs over a three-year period to support the planned expansion of the Company's clinical trial for pediatric brain cancer; the first payment of $900,000 received on October 4, 2024 was recorded as a deferred grant liability as of March 31, 2026 and December 31, 2025, with no grant revenue recognized from the DoD Award as of March 31, 2026.

Commitments

• Houston Lease (commencing ~November 1, 2026, 120-month term): ~11,370 sq ft at 6420 Levit Green Boulevard, Houston, TX; monthly base rent of $58,745 escalating ~3% annually, plus share of direct expenses.
• Charlottesville Lease (expires March 31, 2027): Office space in Charlottesville, Virginia with deferred rent balance of $146,000 as of March 31, 2026 and $159,000 as of December 31, 2025.
• Manufacturing Agreement with SpectronRx (November 5, 2024): Five-year drug product development and manufacturing agreement with initial commitment fee of $300,000; no expenses recognized in the three months ended March 31, 2026.

Legal Proceedings

• General legal proceedings: Company is subject to various claims and contingencies; management assesses probability of loss and accrues or discloses as appropriate, with no specific matters individually identified or quantified.

• Facility structure: The Company holds a margin loan facility (the 'Pershing Credit Facility') with Pershing LLC, an affiliate of The Bank of New York Mellon Corporation; amounts borrowed are due on demand, and the available credit line cannot exceed 91.5% of the value of collateralized marketable securities deposited with Pershing.
• Interest rate terms: Borrowings bear interest at the Federal Open Market Committee target rate (floor of 5.5%) plus a spread of 1.75% and applicable fees of 0.5%, subject to a maximum of the then-applicable Prime Rate as published in The Wall Street Journal plus 3.0%; interest is calculated monthly and, unless paid, is added to the outstanding balance.
• Outstanding balance: As of March 31, 2026 and December 31, 2025, the outstanding balances under the Pershing Credit Facility were $700,000 and $800,000, respectively.

• UTHSCSA License Agreement: On December 31, 2021, the Company entered into a Patent and Know-How License Agreement with The University of Texas Health Science Center at San Antonio (UTHSCSA), under which UTHSCSA granted an irrevocable, perpetual, exclusive, fully paid-up license — with sublicensing rights — to certain patents, know-how, and technology related to biodegradable alginate microspheres (BAM) containing nanoliposomes loaded with imaging and/or therapeutic payloads.
• NanoTx License Agreement — terms: On March 29, 2020, NanoTx, Corp. (NanoTx) granted the Company an irrevocable, perpetual, exclusive, fully paid-up license — with sublicensing rights — to patents, know-how, and technology related to radiolabeled nanoliposomes; upfront consideration was $400,000 in cash and $300,000 in the Company's voting stock.
• NanoTx contingent obligations: The agreement includes success-based milestone and royalty payments tied to clinical, regulatory, and sales milestones, plus a requirement to pay 15% of any non-dilutive monetary awards or grants received from external agencies to support nanoliposome encapsulated BMEDA-chelated radioisotope product development; as of March 31, 2026, there were no accrued payments due to NanoTx as a result of the CPRIT Grant proceeds received.

• Reverse Stock Split: The Company implemented a 1-for-25 reverse split of its common stock effective 12:01 a.m. (Eastern time) on April 2, 2026, with common stock beginning to trade on The Nasdaq Capital Market on a post-split basis at the open of business on April 2, 2026.
• Preferred Stock: 5,000,000 shares of preferred stock ($0.001 par value) are authorized; as of March 31, 2026, there were 938 outstanding shares of Series C Preferred Stock convertible into an aggregate of 1,111 shares of common stock, and 1,014 shares of Series B Convertible Preferred Stock convertible into an aggregate of 15 shares of common stock.
• March 2025 Private Placement settlement: During the three months ended March 31, 2026, the Company paid the March 2025 Private Placement Purchasers $4.5M to fully satisfy the investor liability under the modified Letter Agreement, 272,821 shares were returned and cancelled, the $4.5M of restricted cash restriction lapsed, and as of March 31, 2026 all outstanding warrants from the March 2025 Private Placement have been exercised and all purchasers have received repayments or resold their securities.
• January 2026 Public Offering: On January 13, 2026, the Company completed an underwritten public offering of 1,578,947 shares of common stock and warrants to purchase 1,578,947 shares at a combined public offering price of $9.50 per share and warrant; the underwriter exercised its over-allotment option on January 14, 2026 for additional January 2026 Warrants to purchase 236,837 shares, generating net proceeds of approximately $13.9M after deducting underwriting discounts, commissions, and other offering expenses; each January 2026 Warrant is exercisable at $9.50 per share and expires five years from issuance.
• Outstanding warrants: As of March 31, 2026, total warrants outstanding were 1,941,456, comprising 1,930 May 2024 Series A Warrants, 123,742 May 2024 Series B Warrants, and 1,815,784 January 2026 Warrants, with one share of common stock issuable per warrant upon exercise; the Lincoln Park Purchase Agreement provides the Company the right to sell up to $50M of common stock to Lincoln Park Capital Fund, LLC over 36 months, with up to 2,000,000 shares reserved for issuance and sale under that facility as of March 31, 2026.

• Plan availability: As of March 31, 2026, 95,640 shares remained available under the 2015 New Employee Incentive Plan and only 522 shares remained available under the 2020 Stock Incentive Plan (which provides for up to 852,133 shares).
• Stock option activity: Options outstanding grew from 465,877 at December 31, 2025 to 606,421 at March 31, 2026 after 159,480 grants at a weighted average exercise price of $6.93 and 18,936 cancellations/forfeitures/expirations; exercisable options stood at 109,601 with a weighted average exercise price of $42.11 and aggregate intrinsic value of $— thousand.
• Unrecognized option compensation: Total unrecognized cost for non-vested stock options was approximately $5.2M as of March 31, 2026, expected to be recognized over a weighted average period of 3.17 years.
• RSU activity and unrecognized cost: RSUs unveiled rose from 105,503 at December 31, 2025 to 253,042 at March 31, 2026 (159,481 granted at $6.93 weighted average grant date fair value, vesting over 36 months), with approximately $1.8M of unrecognized compensation cost expected to be recognized over a weighted average period of 2.50 years.

• Single reportable segment: The Company operates under one reportable business segment focused on the development, manufacturing, and commercialization of complex and innovative treatments for patients battling cancer and other life-threatening diseases; the CODM is the Chief Executive Officer, who reviews financial information on a consolidated basis.
• Segment assets: All long-term assets and operations are located in the United States; segment assets are measured as total assets reported on the condensed consolidated balance sheets.
• Expense disaggregation: The table below disaggregates R&D and G&A expenses into 4 categories: (1) clinical, manufacturing and research contracts, (2) personnel-related expenses (including salaries, benefits, and stock-based compensation), (3) professional fees (including lab supplies, contract research, legal, and other professional expenses), and (4) facility and other overhead expenses (including depreciation, occupancy, travel, insurance, and other costs).

• Nasdaq compliance regained: On April 20, 2026, the Company received a notification letter from The Nasdaq Stock Market LLC confirming it had regained compliance with the minimum bid price requirement under Nasdaq Listing Rule 5550(a)(2) for continued listing on The Nasdaq Capital Market, following the Reverse Stock Split that became effective on April 2, 2026.
• Certificate of Correction filed: On May 12, 2026, the Company filed a Certificate of Correction to a Certificate of Amendment to its Amended and Restated Certificate of Incorporation (originally filed April 1, 2026), which had erroneously stated authorized shares of Common Stock (par value $0.001 per share) as 200,000,000 (two hundred million); as corrected, the total authorized shares of Common Stock is two billion (2,000,000,000).

• Lead asset: Rhenium (186Re) obisbemeda is a patented radiotherapy acquired from NanoTx, Corp. on May 7, 2020, targeting CNS and other cancers including GBM, LM, PBC, head and neck cancer, ovarian cancer, breast cancer, and peritoneal metastases, with preclinical data published in peer-reviewed journals.
• NIH funding: The company holds an active $3M award from U.S. National Institutes of Health/National Cancer Institute to support continued clinical development for recurrent GBM through completion of a Phase 2 clinical trial, including enrollment of up to 55 patients.
• Mechanism and differentiation: Rhenium (186Re) obisbemeda delivers radiation directly into GBM tumors via CED catheters using precision brain mapping, potentially delivering up to 20 times greater radiation dose than commonly used EBRT while sparing normal tissue, bypassing the blood-brain barrier, enabling real-time visualization during administration, and requiring only a single short in-patient hospital visit versus EBRT's five-days-per-week outpatient schedule for approximately four to six weeks.

• Disease background: GBM affects approximately 15,000 patients annually in the U.S. and is the most common and lethal form of brain cancer, with average life expectancy less than 24 months, a one-year survival rate of 40%, and a five-year survival rate of around 5%; no FDA-approved treatments exist in the recurrent or progressive setting that can significantly extend life, and it has been nearly a decade since the FDA approved a new therapy for the disease.
• Regulatory designations: In September 2020, the FDA granted both orphan drug designation and Fast Track designations to rhenium (186Re) obisbemeda for the treatment of patients with GBM.
• ReSPECT-GBM trial status: Rhenium (186Re) obisbemeda is under clinical investigation in a Phase 1/2 multicenter, sequential cohort, open-label, volume and dose escalation study (ReSPECT-GBM); Phase 1 has been completed, and the company is targeting full enrollment into Phase 2 by the end of 2026.
• Funding: The trial is funded through Phase 2 in large part by a National Institute of Health/National Cancer Institute grant.

• DoD Award: Effective September 1, 2024, the company entered into an agreement with the Department of Defense office of the Congressionally Directed Medical Research Programs to receive a $3M fund for research and development purposes over a three-year period, to support the planned expansion of the clinical trial for pediatric brain cancer.
• Trial design: The ReSPECT-PBC trial is structured as a Phase 1a/b dose escalation enrolling an estimated 24 patients using a modified 3+3 scheme to establish the MTD and RP2D, followed by a Phase 2a enrolling approximately 32 patients (12 with ependymoma and 20 with HGG) at the RP2D to assess efficacy; the company anticipates enrolling its first patient in 2026.
• Orphan Drug Designation: On April 8, 2026, the FDA granted Orphan Drug Designation to rhenium (186Re) obisbemeda for the treatment of pediatric malignant gliomas.
• Disease burden: Pediatric HGG carries a three-year PFS of 11 ± 3% and three-year OS of 22 ± 5%, with one-year PFS as low as 40% in recent trials, underscoring the high unmet need the trial targets.

• Technology overview: In January 2022, the company licensed Biodegradable Alginate Microsphere ("BAM") patents and technology from The University of Texas Health Science Center at San Antonio ("UTHSCSA") to combine with its Rhenium NanoLiposome technology, creating a novel radioembolization product (188RNL-BAM) intended for intra-arterial delivery of targeted radiation for solid organ cancers including hepatocellular cancer, hepatic metastases, and pancreatic cancer.
• Preclinical status: Preclinical data from an ex vivo embolization experiment using Technetium99m-BAM in a bovine kidney perfusion model was presented at the Society of Interventional Radiology Annual Scientific Meeting, concluding the technology could successfully deliver, embolize, and retain radiation in the target organ; the company transferred the 188RNL-BAM technology from UTHSCSA in 2022 and began planning early preclinical studies to support a future FDA IND submission.
• Regulatory and market context: The FDA has informed the company that 188RNL-BAM will be regulated as a medical device under the FDCA; the intended initial clinical target is liver cancer, described as the sixth most common and third deadliest cancer worldwide, with U.S. annual incidence of 42,000 and deaths of 30,000.

• Platform description: The CNSide CSF Assay Platform consists of 4 LDTs for detection, quantification, and characterization of tumor cells in patients with leptomeningeal metastases (LM), employing cellular assays (TCE, ICC, FISH) and molecular assays (NGS); it is currently used as an exploratory endpoint in the ReSPECT-LM trial.
• Commercial rollout: Since acquiring the CNSide Platform in 2024, the company re-introduced it in Texas in August 2025, signed national agreements with UnitedHealthcare Insurance Company, Humana, Inc., Highmark, and Blue Shield of California, and obtained state licensure for 49 of 50 U.S. states, with the remaining New York license on track for 2027; the company also expects to launch additional CSF tumor characterization tests later in 2026.
• Revenue status: Commercial billing for the diagnostic CNSide business began during the three months ended March 31, 2026, but net diagnostic revenue was immaterial; in April 2026, management obtained approval of proprietary laboratory analyses codes from significant medical payors, and the company expects diagnostic revenue to increase during the remainder of 2026 and beyond.

• CPRIT grant revenue: Recognized $1M and $1.1M of grant revenue during the three months ended March 31, 2026 and 2025, respectively, representing CPRIT's share of costs incurred for rhenium (186Re) obisbemeda development for the treatment of patients with LM.

• Category composition: R&D expenses consist of costs associated with design, development, testing, and enhancement of product candidates, payment of regulatory fees, laboratory supplies, preclinical studies, and clinical studies.
• Period-over-period increase: Total R&D expenses rose by approximately $1.1M in the three months ended March 31, 2026 vs. the same period in 2025, driven by increases of $400,000 in clinical expenses, $300,000 in diagnostics, $300,000 in professional research and development services, and $100,000 in other research and development expenses.
• Forward outlook: Management expects aggregate R&D expenditures to increase during the remainder of 2026 vs. the comparable 2025 period, citing increased costs for the ReSPECT-LM clinical trial (for which CPRIT grant funding is expected to be available), manufacturing scale up for rhenium (186Re) obisbemeda commercial and approval trial drug availability, and initial patient enrollments in the ReSPECT-PBC clinical trial together with expansion of CNSide research and development teams.

• Composition: General and administrative expenses include costs for administrative personnel, legal and other professional expenses, and general corporate expenses.
• Year-over-year increase: Total G&A expenses rose by $2.4M in the three months ended March 31, 2026 vs. the same period in 2025, driven by a $1.4M increase in compensation expense (including $900,000 in stock-based compensation), $500,000 in legal and professional fees, $300,000 in rent expense, and $200,000 in other general and administrative expenses.
• Forward outlook: Management expects G&A expenditures to increase during the remainder of 2026 vs. comparable 2025 periods as the company expands the CNSide commercial operations team, including sales, customer service, and laboratory operations.

• Driver of increase: Stock-based compensation expense rose to $1M in the three months ended March 31, 2026 from $148,000 in the same period of 2025, primarily due to an increase in the number of awards granted, partially offset by a decrease in the grant-date fair value of equity awards granted.
• G&A concentration: Virtually all of the expense was in General and administrative ($1M in 2026 vs. $141,000 in 2025), with Research and development contributing only $5,000 in 2026 vs. $7,000 in 2025.

• Interest income: Increased to $190,000 in Q1 2026 from $1,000 in Q1 2025, primarily due to a higher investment balance in 2026.
• Interest expense: Declined to ($17,000) from ($548,000), as the prior-year period included interest on Funding Notes issued and redeemed during Q1 2025.
• Prior-year non-recurring charges: Q1 2025 included $3.2M in financing expenses related to the March 2025 PIPE and February 2025 transactions, ($9.1M) from the change in fair value of derivative instruments (primarily the liability-classified March 2025 Series B Warrants remeasured immediately prior to exercise before reclassification as equity), and ($964,000) in warrant issuance costs related to the March 2025 Private Placement — none of which recurred in Q1 2026.
• Net other income (expense): Swung from ($13.9M) in Q1 2025 to $173,000 in Q1 2026, reflecting the absence of the prior-year financing-related charges.

• Liquidity position: Cash, cash equivalents and restricted cash declined to $3M at March 31, 2026 from $8.8M at December 31, 2025, while working capital improved to $10.1M from $2.9M over the same period (current assets of $18M vs. current liabilities of $8M at March 31, 2026).
• Going concern: The company incurred net losses of $6.9M for the three months ended March 31, 2026, carries an accumulated deficit of $522.8M as of March 31, 2026, and used net cash of $6.2M in operating activities for the quarter — factors management states raise substantial doubt about its ability to continue as a going concern.
• Funding sources and risk: Operating losses have been funded primarily from issuance of common and preferred equity, warrants, convertible loan, term loan, a line of credit facility with Pershing, and grant funding; management states there is no assurance that additional capital can be raised, and inability to do so would have a material and adverse impact on operations and the ability to satisfy obligations.

• Structure: On January 13, 2026, the Company completed an underwritten public offering of 1,578,947 shares of common stock (par value $0.001 per share) paired with warrants to purchase 1,578,947 shares of common stock (the "January 2026 Warrants"), at a combined public offering price of $9.50 per share and warrant.
• Over-allotment: The underwriter was granted a 30-day option to purchase up to an additional 236,837 shares and/or January 2026 Warrants to purchase up to 236,837 shares at the public offering price; on January 14, 2026, the underwriter exercised the over-allotment option with respect to the additional January 2026 Warrants only.
• Warrant terms: Each January 2026 Warrant is immediately exercisable at an exercise price of $9.50 per share and expires five years from the date of issuance.
• Net proceeds: Net proceeds from the offering were approximately $13.9M after deducting underwriting discounts and commissions and other offering expenses payable by the Company.

• February 2025 SPEA: On February 13, 2025, the company issued secured convertible promissory notes ("Funding Notes") in the aggregate principal amount of $3.3M and common stock purchase warrants ("February 2025 Warrants") to purchase 120,080 shares at an exercise price of $28.00 per share; the aggregate purchase price was approximately $3.7M, including payment of $3.125 per February 2025 Warrant under Nasdaq listing rules.
• Exchange Notes: Also on February 13, 2025, the company issued $3.2M in secured convertible promissory notes ("Exchange Notes") to Outside Investors in exchange for cancellation of 141,729 May 2024 Series A Warrants; simultaneously, those investors entered into a second amendment to the May 2024 Purchase Agreement to eliminate the Financing Restrictions.
• March 2025 Private Placement: On March 4, 2025, the company entered into the March 2025 SPA for gross proceeds of approximately $15M (closing March 7, 2025, net of $1.4M expenses), issuing 162,789 shares of common stock and 958,896 Pre-Funded Warrants, each accompanied by one March 2025 Series A Warrant (initial exercise price $33.00, 5-year term post-stockholder approval) and one March 2025 Series B Warrant (initial exercise price $49.50, 2.5-year term post-stockholder approval); the Funding Notes were repurchased and Exchange Notes were canceled in connection with this placement.
• Warrant modifications: On May 2, 2025, stockholders approved the March 2025 Series A and Series B Warrants and an authorized share capital increase; the exercise prices of the March 2025 Series A Warrants and March 2023 Series B Warrants were reset on May 19, 2025 to $10.9325 per share, and prior to modification of the March 2025 Series B Warrants, certain March 2025 Series B Warrants were cashless exercised resulting in issuance of 859,299 shares of common stock.

• Letter Agreement overview: On June 17, 2025, the Company and the Purchasers entered into a Letter Agreement to minimize the dilutive impact of the March 2025 Private Placement, which extinguished the March 2025 Series A Warrants, modified the March 2025 Series B Warrants, and provided for the return of Private Placement Shares and Pre-Funded Warrants.
• Series B Warrant modifications: The March 2025 Series B Warrants were amended to (a) reduce aggregate Series B Warrant Shares issuable to up to 1,421,455, (b) reduce the alternative cashless exercise ratio from 3:1 to 1:1, and (c) remove provisions that would reduce stockholders' equity; as a result, the Amended March 2025 Series B Warrants no longer fail indexation guidance under ASC 815 and the related warrant liability was reclassified to equity, after which 1,391,781 Amended March 2025 Series B Warrants were cashless exercised.
• Repurchase option and Q1 2026 activity: Purchasers agreed to return an aggregate of 489,679 Private Placement Shares and Pre-Funded Warrants (issuable for 425,346 Pre-Funded Warrant Shares) at $16.50 per Private Placement Share and $16.475 per Pre-Funded Warrant, with the Company obligated to repay 115% of such value using 90% of proceeds from capital raised subsequent to July 1, 2025; during the three months ended March 31, 2026, the Company paid the Purchasers $4.5M and 272,821 shares were returned and cancelled.
• Support Letters: On July 11, 2025, Support Letters were entered into to modify the Subsequent Financing Percentage from 90% to 50% during a 30-day Modification Period preceding any fiscal quarter-end where the Company reasonably believes stockholders' equity will fall below $3M, reverting to 90% after the Modification Period; each Support Letter also grants the purchaser party a participation right in certain future financings for a period of 12 months.

• First Amendment terms: In connection with the March 2025 Purchase Agreement, the company entered into the First Amendment to the February 2025 SPEA, under which — contingent on consummation of the March 2025 Private Placement — the company agreed to repurchase from the Investors $3.4M in principal amount of the Funding Notes and accrued interest, along with the February 2025 Warrants issued pursuant to the February 2025 SPEA, for an aggregate purchase price of $4.2M.
• New Financing Restrictions eliminated: In exchange for the repurchase of the Funding Notes and February 2025 SPEA Warrants, the February 2025 Purchasers agreed to consent to the March 2025 Private Placement and eliminate the New Financing Restrictions (the limitations and restrictions on the company's ability to issue securities and investor participation rights in future equity and equity-linked offerings that were included in the February 2025 SPEA).

• Lincoln Park agreement: On June 17, 2025, the company entered into the Lincoln Park Purchase Agreement under which Lincoln Park Capital Fund committed to purchase up to $50M of shares of common stock at the company's sole discretion over a 36-month period commencing June 23, 2025, subject to certain conditions and limitations.
• Registration statements: On June 23, 2025, an Initial Registration Statement was declared effective covering resale of up to 680,000 shares; on August 14, 2025, a Second Registration Statement was declared effective covering resale of up to 1,320,000 shares.
• Commitment fee: The initial commitment fee was recorded as a reduction to additional paid-in capital; an additional commitment fee of $500,000 (payable in cash, shares, or a combination) is triggered if and when the company sells over $25M of common stock under the agreement.

• Compliance status: The company is currently in compliance with the Minimum Stockholders' Equity Requirement and is subject to monitoring through August 22, 2026.
• Delisting risk: If the Staff determines during the monitoring period that the company no longer satisfies the Minimum Stockholders' Equity Requirement (and no alternative standard under Nasdaq Listing Rule 5550(b) is met), no plan of compliance will be permitted, no additional time or cure period will be granted, and the Staff will issue a delist determination letter; the company would then have the opportunity to request a new hearing before the Nasdaq Hearings Panel, which would stay further Staff action pending the hearing outcome.

• Nasdaq compliance: On April 20, 2026, the company received a Notification Letter from The Nasdaq Stock Market LLC confirming it had regained compliance with the Minimum Bid Requirement, following the Reverse Stock Split that became effective on April 2, 2026.
• Going concern: The condensed consolidated financial statements were prepared on a going-concern basis; management acknowledges ongoing uncertainty about the ability to continue as a going concern and states no adjustments have been made to reflect possible future effects on asset recoverability or liability classification.
• Funding needs: Operating losses have been funded primarily through issuance of common and preferred equity, warrants, convertible loans, a term loan, a margin loan facility under a line of credit with Pershing, and grant funding; the company states it will continue to need to raise additional cash through equity offerings, debt financings, and potential collaboration, license, or development agreements to fund clinical programs, commercialization of CNSide, and other operations in the next twelve months from filing.

• CPRIT Contract matching funds: Under the CPRIT Contract, the company receives matching funds for approximately two-thirds of development costs for REYOBIQ for the treatment of patients with LM; the contract is effective for three years and CPRIT may require repayment of some or all disbursed grant proceeds, with interest not to exceed 5% annually, upon early termination.
• Other obligations: As of March 31, 2026, the company has no purchase commitments or long-term contractual obligations other than lease obligations and the CPRIT arrangement described above, and no off-balance sheet arrangements material to investors.

• Q1 2026 operating cash use: Net cash used in operating activities for the three months ended March 31, 2026 was $6.2M, driven primarily by a net loss of $6.9M and $400,000 of changes to operating assets and liabilities, partially offset by $1M of stock-based compensation expense and $100,000 of depreciation and amortization.
• Prior-year comparison: Net cash used in operating activities for the three months ended March 31, 2025 was also $6.2M, up from $4.5M in the same period of 2024, primarily due to an increase to net loss of $14.1M, offset by non-cash charges of $12.7M.

• Investing outflows (Q1 2026): Net cash used in investing activities was $8.5M for the three months ended March 31, 2026, driven by purchases of short-term investments of $9.7M and property and equipment of $800,000, partially offset by redemption of short-term investments of $2M.
• Investing inflows (Q1 2025): Net cash provided by investing activities for the three months ended March 31, 2025 was limited to maturities of short-term investments of $3.5M.