C4 Therapeutics (CCCC) Q3 2026 earnings review
C4 Therapeutics clears key drug safety step, but revenue drops
C4 Therapeutics advanced its lead blood cancer drug into higher-dose testing while keeping spending in check. Collaboration revenue fell 25% from a year ago to $8.5 million after older Merck research programs ended, though newer payments from Roche lifted revenue from the second quarter. Reported net loss per share shrank by nearly two-thirds, but by our math underlying net loss crept up 2% once last year's one-time asset write-down is excluded, because the share count nearly doubled. Chief executive Andrew Hirsch kept every 2027 trial target and the 2028 cash runway unchanged.
| Collaboration revenue | $8.5M -25% from a year ago |
|---|---|
| Net loss excluding last year's write-down | $21.8M +2% from a year ago by our math |
| Cash and marketable securities | $275M $300M last quarter |
| Cash runway outlook | Unchanged funds plan to the end of 2028 |
⚖️ Verdict: 🟢 Bullish
The story got better because cemsidomide passed its first safety check when paired with Pfizer's approved myeloma drug elranatamab, clearing the way for higher-dose testing and an expanded patient group. Early blood tests from the first two patients also showed the combination stimulated immune cells without exhausting them. One caution: the company still has not delivered the partner drug candidate promised for 2026, and deferred revenue fell 18% from last quarter as it burned through upfront partner cash.
The question now is whether early immune-cell activity in blood tests turns into deeper, longer-lasting tumor shrinkage in patients next year. Either the 2027 trial readouts show cemsidomide works safely alongside standard myeloma drugs in earlier treatment lines, or side effects and modest response rates limit it to late-stage patients. Clinical data from the elranatamab combination in mid-2027 and the Phase 2 trial in the second half of 2027 will settle it.
🐂 Bull Case
Elranatamab Combination Clears First Safety Test
"Throughout the year, we have continued to build evidence supporting cemsidomide’s potential as a backbone therapy across the multiple myeloma treatment landscape," chief executive Andrew Hirsch said. Cemsidomide is an experimental pill designed to destroy two proteins that help blood cancer cells survive while also stimulating the patient's immune system.
This quarter, the drug passed its first safety check when paired with Pfizer's elranatamab, an approved antibody therapy that links immune cells to cancer cells. "The Safety Data Review Committee determined that the 75 µg cemsidomide dose level was safe to proceed," the biotech company said, allowing it to expand testing at 75 micrograms and test a higher 100-microgram dose. Early blood tests from the first two combination patients also showed the drug helped "drive T-cell activation and expansion as well as prevent T-cell exhaustion".
Clearing the 75-microgram dose matters because C4 Therapeutics already chose that same starting dose for a separate combination trial with two standard myeloma drugs, daratumumab and carfilzomib, starting in the first half of 2027. Moving safely to 100 micrograms also tests whether patients can tolerate the higher dose that produced a 53% response rate, compared with 40% at 75 micrograms, in earlier study results.
What to watch: clinical results from all evaluated dose groups in the elranatamab combination trial in mid-2027. Strong tumor shrinkage without severe immune side effects would show cemsidomide can move into earlier stages of myeloma treatment.
Roche Deal Cushions Operating Cash Burn
As a clinical-stage drug developer with no approved products on the market, the Watertown-based company relies on its cash reserves and partner payments to fund multi-year cancer trials. Management wants to reach its 2027 clinical readouts without needing emergency financing.
C4 Therapeutics ended September with $274.7 million in cash and marketable securities, down $25.8 million from June. Revenue rose 27.5% from the second quarter to $8.5 million as the drugmaker booked more money from its April agreement with Roche for degrader-antibody conjugates, which pair protein-destroying drugs with targeted antibodies. Research spending fell 4.6% from a year ago to $24.8 million because of "lower personnel costs from reduced stock-based compensation expense".
The company reiterated that its cash will "fund its operating plan to the end of 2028". By our math, spreading $274.7 million across the nine quarters to the end of 2028 allows an average cash burn of $30.5 million per quarter, so this quarter's $25.8 million use of cash leaves room for trial costs to rise as three cemsidomide studies run at once in 2027.
What to watch: quarterly cash use in the first half of 2027 as the new daratumumab and carfilzomib combination study begins dosing patients. Keeping quarterly cash burn below $30.5 million by our math will keep the 2028 runway intact.
🐻 Bear Case
Partner Revenue Drops After Merck Exit
Until cemsidomide wins regulatory approval, C4 Therapeutics generates all of its revenue from research partnerships with larger pharmaceutical companies, including Roche and Biogen. Those agreements bring in upfront cash and milestone payments when experimental drugs hit research targets.
Collaboration revenue fell 24.6% from a year ago to $8.5 million in the third quarter, and dropped 14.7% over the first nine months of 2026 to $21.3 million. The drug developer said the drop stemmed from the "conclusion of certain research activities in 2025 associated with the collaborations with Merck and Merck KGaA, Darmstadt Germany", which outweighed the newer revenue from Roche.
Losing the Merck research stream means Roche now carries a heavier share of top-line funding while deferred revenue is already being drawn down. To refill the partner pipeline, the group promised to "Deliver at least one development candidate to a collaboration partner" by the end of 2026, leaving less than two months to hit the target.
What to watch: announcement of the partner development candidate delivery before December 31, 2026. Delivering the candidate on time triggers partner progress and shows the discovery platform can replace the concluded Merck work.
Smaller Per-Share Loss Comes From Share Dilution
On the surface, the income statement shows a sharp improvement in bottom-line loss, with reported net loss falling 32.1% from a year ago to $21.8 million and net loss per share dropping from $0.44 to $0.16.
- Weighted-average diluted shares: 136.1 million, up 87.5% from 72.6 million a year ago
- Net loss excluding last year's one-off $10.7 million asset write-down: up 1.9% from a year ago by our math
- Stock-based compensation: the primary driver of the 5.3% drop in underlying operating expenses
The per-share improvement does not reflect a smaller cash deficit. Last year's third quarter included a one-time $10.7 million charge for impaired assets; stripping that out by our math leaves last year's net loss at $21.4 million, slightly better than this quarter's $21.8 million loss. The per-share loss shrank by nearly two-thirds only because the share count nearly doubled after an October 2025 stock offering and $33.5 million of second-quarter share sales, reducing each existing share's claim on future cemsidomide profits.
What to watch: weighted-average share count and any new at-the-market share sales in the fourth-quarter report. Further share issuance while cash stands at $274.7 million would dilute shareholders ahead of the 2027 clinical readouts.
👓 Other Themes
DNA Library Expands Drug Discovery Platform
In October 2026, C4 Therapeutics unveiled a new DNA-encoded library at the Targeted Protein Degradation Summit to pair with its TORPEDO drug-design platform. The tool uses DNA tags to screen large collections of molecules that bind to cereblon, a cellular recycling protein, helping scientists find new drug candidates faster. The upgrade supports early research collaborations, though it has no immediate impact on revenue or 2027 clinical trials.
💲 Other KPIs
Deferred revenue — upfront cash from partners like Roche that will be booked as revenue as research work is completed — fell 17.6% from the second quarter's $40.4 million and 10.1% from a year ago. The balance remains 17.5% above year-end 2025 following May's $20 million Roche payment, but fell sequentially as C4 Therapeutics worked down that upfront cash.
Overhead and administrative spending dropped 7.4% from a year ago and 3.9% from the second quarter. The oncology company has trimmed overhead costs for four straight quarters compared with prior-year levels, driven mainly by lower stock-based compensation for employees, helping keep total operating expenses flat with the second quarter at $33.1 million.
🔮 Guidance
Unchanged. Management still expects its $274.7 million in cash and marketable securities to fund operations through the end of 2028. By our math, that nine-quarter span allows an average cash burn of $30.5 million per quarter, well above the third quarter's $25.8 million cash drop and covering all scheduled 2027 cemsidomide data readouts.
Unchanged. The biotech group still plans to deliver at least one drug candidate to a partner before the end of 2026 and advance existing collaborations toward milestone payments. With the third quarter finished and no candidate handoff announced in the November 5 release, delivery must happen in the final eight weeks of the year.
Unchanged. C4 Therapeutics remains on schedule to finish enrolling roughly 100 late-stage multiple myeloma patients in the first quarter of 2027, with initial tumor response data due in the second half of 2027. Chief executive Andrew Hirsch said "we believe next year will be pivotal in establishing cemsidomide’s therapeutic profile".
Unchanged. After clearing the initial 75-microgram safety cohort with Pfizer's elranatamab this quarter, the company expects clinical data from all evaluated dose groups in mid-2027. It also remains on track to start a second Phase 1b study in the first half of 2027 combining cemsidomide at a 75-microgram starting dose with daratumumab or carfilzomib.
❓ Key Questions
Which partner receives the 2026 drug candidate?
The company maintained its goal to deliver at least one development candidate to a partner by year-end 2026. Investors need to know whether this handoff goes to Roche, Biogen, or Merck KGaA, and whether it triggers an immediate cash milestone payment.
How many patients are enrolled in MOMENTUM?
Management expects to complete enrollment of roughly 100 late-line myeloma patients in the Phase 2 MOMENTUM study in the first quarter of 2027, after dosing the first patient in February 2026, but has not shared the current patient count.
Did the company sell shares in the third quarter?
Weighted-average diluted shares rose by 5.4 million from the second quarter to 136.1 million. Because the press release lacks a full cash flow statement, investors cannot yet see whether C4 Therapeutics issued more stock under its at-the-market program after June.
How many dose levels will the elranatamab study test?
The Phase 1b combination trial advanced to a 100-microgram dose escalation group while expanding the 75-microgram group. Management has not stated whether 100 micrograms is the highest planned dose before reporting data from all evaluated cohorts in mid-2027.