Cambridge biotech tracker · Boston
Seaport Therapeutics
Listed on Nasdaq as SPTX, filed under SEC industry code 2834 (pharmaceutical preparations). Fiscal year ends in December. Numbers below are from the company’s own SEC filings through Q3 '26.
- Cash & investments
- $404M
- Q3 '26 · Sep 30, 2026
- Burn per quarter
- $21.2M
- avg. operating cash flow, 4 qtrs
- Runway
- 4.8 yrs
- 3+ years
- Net loss
- $26.4M
- Q3 '26
- R&D expense
- $23.9M
- 79% of opex
- Raised, last 4 qtrs
- +$240M
- net financing cash flow
- Next readout
- Mar 2027
- Phase 2 · cash past the catalyst
Cash & investments
Quarter-end balance
Operating cash flow
Per quarter; below zero is burn
R&D expense
Per quarter
Two views of the runway
Compare across the clusterThe outside view
4.8 years
Cash at Q3 '26 divided by the average burn of the last four quarters, $7.1M a month.
Management’s own date
Into 2029
Jan–Dec 2029
That implies $10.3M to $14.9M a month, 1.5–2.1× the recent pace.
Planning to spend faster“Based on our current operating plans, we believe that our existing cash, cash equivalents and investments will be sufficient to fund our operating expenses and capital expenditure requirements into 2029.”
Cash against the calendar
What the runway has to reach.
Mar 2027estimated
A Study to Evaluate the Efficacy and Safety of SPT-300 (GlyphAllo) in Participants With Major Depressive Disorder, With or Without Anxious Distress (BUOY-1 Study)
Major Depressive Disorder (MDD) · Major Depressive Disorder With Anxious Distress
NCT07065240 on ClinicalTrials.govDoes the cash reach it?
Cash past the catalyst
- Runway
- 4.8 years
- Time to the date
- 4 months
It is about 4 months out. At the current burn there is roughly 53 months of cash left on the far side of it, which is enough room to raise on the result rather than ahead of it.
Pipeline
2 active trials, through phase 2.
Phase 2 · 2
| Study | Phase | Status | Enrolled | Primary completion |
|---|---|---|---|---|
| A Study to Evaluate the Efficacy and Safety of SPT-300 (GlyphAllo) in Participants With Major Depressive Disorder, With or Without Anxious Distress (BUOY-1 Study)NCT07065240 · Major Depressive Disorder (MDD), Major Depressive Disorder With Anxious DistressPhase 2Mar 2027est. | Phase 2 | Recruiting | ||
| An Open-Label Extension Study to Evaluate the Safety and Tolerability of SPT-300 (GlyphAllo) in Participants With Major Depressive Disorder, With or Without Anxious Distress (BUOY-1 OLE Study)NCT07161700 · Major Depressive Disorder (MDD), Major Depressive Disorder With Anxious DistressPhase 2May 2027est.· not a catalyst | Phase 2 | Enrolling by invitation |
Interventional studies where this company is the lead sponsor, from ClinicalTrials.gov. Primary completion is when the last patient is measured on the primary endpoint, which is when the data exists rather than when it is announced. Extension, rollover and healthy-volunteer studies are listed but marked as non-catalysts, because they finish long after the result that mattered. Sponsors revise these dates as enrollment moves, so an estimate is a plan rather than a promise.
The controller’s read
What the filings say.
Generated from the numbers above using the same questions I ask when I open a client’s books: how long the cash lasts, what is driving the gap between loss and burn, and where the accounting judgment sits.
Get this read on your companyThe cash clears the next catalyst
The next dated event is a phase 2 readout in Mar 2027, about 4 months out. That leaves roughly 53 months of cash afterwards, which is the position you want: the raise can be negotiated on the data instead of on the calendar.
About 4.8 years of runway
Cash and investments of $404M at Q3 '26 against an average operating cash burn of $21.2M per quarter over the last four reported quarters runs out around June 2031. More than two years of runway means the finance conversation is about deployment, not survival.
Cash position up $170M since Q4 '25
Net financing inflows of $240M over the last four quarters, from equity, debt, or ATM sales, more than covered operating burn. The balance is the number the board watches; the trend is the number the auditors watch.
R&D is 79% of operating expenses
$23.9M of R&D against $30.3M of total operating expenses in Q3 '26, with G&A at $6.5M. For a clinical-stage company, the accounting questions live inside that R&D line: CRO and CMC accruals, milestone recognition, and what gets capitalized versus expensed under ASC 730.
Accumulated deficit of $229M
Total losses since inception. It is also roughly the size of the net operating loss carryforward the tax provision has to track, subject to Section 382 limits after each ownership change.
Quarterly detail, eight quarters
| Quarter | Cash & inv. | Op. cash flow | Net income | R&D | G&A | Revenue | Stock comp | Financing |
|---|---|---|---|---|---|---|---|---|
| Q1 '25 · Mar 31, 25 | — | −$20.2M | −$13.1M | $10.5M | $5.7M | — | $1.6M | $0 |
| Q2 '25 · Jun 30, 25 | — | −$15.3M | −$15.1M | $13.4M | $5.1M | — | $1.8M | $0 |
| Q3 '25 · Sep 30, 25 | — | −$15.8M | −$22.5M | $20.5M | $5.0M | — | $1.8M | $1K |
| Q4 '25 · Dec 31, 25 | $234M | — | — | — | — | — | — | — |
| Q1 '26 · Mar 31, 26 | $213M | −$20.2M | −$25.4M | $21.4M | $6.1M | — | $2.6M | −$783K |
| Q2 '26 · Jun 30, 26 | $427M | −$26.1M | −$62.6M | $24.6M | $41.2M | — | $36.9M | $241M |
| Q3 '26 · Sep 30, 26 | $404M | −$22.7M | −$26.4M | $23.9M | $6.5M | — | $2.4M | −$97K |
Source: SEC EDGAR XBRL company facts, latest filed value for each period. Fourth quarters are derived from annual less nine-month figures; quarterly cash flows are derived from year-to-date amounts. Not investment advice. If a figure disagrees with the filing, the filing is right.