Sutro Biopharma, Inc. — FY 2022 Form 10-K
Reporting period: Fiscal year ended December 31, 2022. This is an annual filing, not a standalone fourth-quarter report; the filing text does not provide clear Q4-only financial results. Sutro is a clinical-stage oncology company with no approved products and no commercial product sales. Revenue is primarily from collaborations, licenses, research, and manufacturing services.
Financial performance and liquidity
| Metric | 2022 | 2021 | Change |
|---|---|---|---|
| Revenue | $67.8 million | $61.9 million | Up 10% |
| Research and development expense | $137.2 million | $104.4 million | Up 31% |
| General and administrative expense | $59.5 million | $56.0 million | Up 6% |
| Operating loss | $128.9 million | $98.5 million | Loss widened 31% |
| Net loss | $119.2 million | $105.5 million | Loss widened 13% |
| Basic and diluted net loss per share | $2.35 | $2.29 | Loss per share increased |
| Net cash from (used in) operations | $3.5 million | $(81.7) million | Improved |
Cash and liquidity: At year-end, cash, cash equivalents and marketable securities totaled $302.3 million, compared with $229.5 million in 2021. Sutro also held Vaxcyte equity securities valued at $32.0 million. Management said available resources were expected to fund operations for at least 12 months following the filing date, while noting that additional financing will be needed to advance development and fund operations over the longer term.
Debt and obligations: Debt was $16.3 million at December 31, 2022, versus $25.1 million in 2021. The Oxford Finance/Silicon Valley Bank term loan matures March 1, 2024; $12.5 million was classified as current. It is secured by substantially all assets other than intellectual property, includes a $10.0 million minimum unrestricted-cash covenant, and contains restrictive covenants. Lease liabilities totaled $34.2 million.
Margins and cash-flow context: Operating loss was approximately 190% of revenue in 2022 (approximately 159% in 2021); the business remained materially loss-making. 2022 operating cash flow was positive largely because deferred revenue increased by $93.6 million, principally following the Astellas upfront payment; it should not be read as evidence of recurring operating profitability. Investing cash outflow was $35.0 million and financing cash inflow was $48.3 million.
Material changes and notable items
- Revenue increased by $5.9 million, but included significant collaboration-related and nonrecurring receipts. Tasly contributed $25.0 million of upfront license revenue; Astellas contributed $10.9 million of recognized revenue, including a $5.1 million financing-component amount; and BioNova contributed $4.0 million. Merck revenue fell $31.2 million year over year, partly reflecting completion of prior performance obligations and the timing of contingent payments.
- R&D expense rose $32.8 million, primarily due to higher personnel costs, laboratory and clinical-development spending, and outside services. Total operating expenses increased 23%.
- The net loss included a $12.1 million unrealized gain on Vaxcyte shares, compared with a $4.5 million unrealized loss in 2021. Sutro sold Vaxcyte shares for $28.7 million net proceeds and ended the year with 667,780 shares valued at $32.0 million. These valuation changes can materially affect reported earnings without representing operating performance.
- Sutro issued 10.3 million shares through its at-the-market program in 2022, raising approximately $56.3 million net. Shares outstanding at year-end were 57.5 million, versus 46.3 million a year earlier. Through March 27, 2023, it sold another 1.64 million ATM shares for $10.9 million net proceeds.
- Astellas paid a $90.0 million upfront amount under a collaboration covering up to three immunostimulatory ADC targets. At year-end, $86.1 million remained deferred; revenue recognition is expected over the performance period. The auditor identified accounting for this agreement as a critical audit matter due to judgments over performance obligations, transaction price, and standalone selling prices.
Business, outlook, and risks
- Luvelta (STRO-002): Lead FolRα-targeted ADC for ovarian and endometrial cancers. In the Phase 1 dose-expansion data reported in January 2023, FolRα-selected ovarian-cancer patients (TPS >25%) had a reported 37.5% response rate, median duration of response of 5.5 months, and median progression-free survival of 6.1 months. These were preliminary company-reported results, not confirmatory trial results. One Grade 5 febrile-neutropenia event was reported at the 5.2 mg/kg starting dose; the protocol was updated to require dose reduction for Grade 4 neutropenia. A small exploratory cohort suggested prophylactic pegfilgrastim reduced severe neutropenia and dose delays.
- Management expected to start a registration-directed trial for platinum-resistant ovarian cancer in the first half of 2023, following FDA discussions about a design that might support accelerated approval. The filing does not establish that the FDA will accept the design or that accelerated approval will be achieved. Luvelta has FDA Fast Track designation for a specified ovarian-cancer population and Orphan Drug Designation for pediatric CBF/GLIS AML.
- Compassionate-use data in 17 pediatric patients with relapsed/refractory CBF/GLIS AML included eight complete remissions; the evidence is preliminary and requires company-sponsored clinical evaluation. Management planned an IND submission for this indication in the first half of 2023 and for non-small cell lung cancer in 2023 or early 2024.
- STRO-001: CD74-targeted ADC in Phase 1 development for B-cell malignancies. Sutro had completed dose escalation and paused further enrollment after identifying the maximum tolerated dose. BioNova reported first-patient dosing in China in February 2023.
- STRO-003: Preclinical ROR1-targeted ADC. Management expected IND-enabling work to finish in Q1 2024 and anticipated Phase 1 safety studies in 2024; these are plans, not assured outcomes.
- Collaborations: Merck’s MK-1484 entered Phase 1 in 2022, while BMS’s CC-99712 remained in clinical development. EMD Serono decided to close the M1231 Phase 1a trial and not start the planned expansion, citing portfolio strategy. Vaxcyte’s option agreement provided Sutro $10.0 million cash and $7.5 million in Vaxcyte shares; further payments depend on agreement completion, option exercise, and milestones.
- Principal risks: Substantial continuing losses, clinical and regulatory uncertainty, need for future capital, trial delays or adverse safety findings, competition (including an already FDA-approved FolRα ADC), reliance on collaborators and third-party manufacturers, and patent and scale-up risks. The company reported that unfavorable capital markets, inflation, and interest rates could constrain financing.
- Banking event after year-end: Sutro disclosed that SVB was closed on March 10, 2023. It reported full access to its cash and investments on March 13 and subsequently amended its loan agreement to permit cash at multiple financial institutions, while noting potential short-term payment or transfer disruption during the transition.
- Other contingencies and controls: Sutro reported no legal proceedings believed to have a material adverse effect. Management concluded disclosure controls and internal control over financial reporting were effective as of year-end; the auditor did not provide an internal-control attestation.
Important facts for investors to verify
- Review the complete, updated luvelta dataset, including patient numbers, biomarker definition, response durability, follow-up, adverse events, and whether confirmatory studies support the preliminary findings.
- Check actual initiation, design, enrollment, and regulatory feedback for the planned luvelta registration-directed trial and other planned INDs against the timelines stated in the filing.
- Assess cash runway using current spending, deferred collaboration obligations, debt payments due in 2023–2024, and post-year-end ATM share issuance; distinguish reported operating cash flow from recurring cash generation.
- Track collaboration performance and payment conditions, particularly Astellas deferred revenue and future milestones, Tasly’s amended terms and milestone triggers, BioNova’s option status, and the status of M1231.
- Monitor dilution and Vaxcyte-share valuation exposure, as well as the loan covenant, collateral, maturity, and cash-management changes following the SVB disruption.