NEW YORK, May 28, 2026, 08:01 EDT
- C4 Therapeutics shares last changed hands at $3.74 before the Nasdaq open, after a 7.16% gain on May 27.
- The move comes ahead of ASCO and EHA cancer-meeting updates tied to cemsidomide, its multiple-myeloma drug candidate.
- Peer moves were mixed in early U.S. trading, with Arvinas lower and Kymera and Nurix higher.
C4 Therapeutics Inc. shares held near a one-year high in early U.S. trading on Thursday, keeping the small biotech in focus after a sharp gain in the prior session and ahead of fresh cancer-drug meeting updates.
The stock was last indicated at $3.74 before the regular Nasdaq session, matching Wednesday’s close after a 7.16% rise. The company’s own stock data showed C4 touched $3.97 on May 27, up from a May 26 close of $3.49.
The timing matters. C4 is heading into the American Society of Clinical Oncology meeting, which starts May 29, and the European Hematology Association congress in June with investors watching cemsidomide, its lead multiple-myeloma candidate. Multiple myeloma is a blood cancer, and cemsidomide is designed to degrade disease-linked proteins rather than simply block them.
C4 said a trial-in-progress poster for its Phase 2 MOMENTUM study was accepted for ASCO, while updated Phase 1 cemsidomide data are due at EHA on June 12. The company also listed a May 26 TD Cowen oncology fireside chat as a past event and a June 3 Jefferies Global Healthcare Conference appearance as upcoming.
Nasdaq’s regular session opens at 9:30 a.m. Eastern time, and May 28 is not listed among U.S. equity market holidays for 2026. The last full closure was Memorial Day on May 25, according to Nasdaq’s trading calendar.
The recent buying follows a broader reset in how investors view C4’s cash runway and partnership optionality. In its first-quarter update, the Watertown, Massachusetts-based company reported $268.3 million in cash, equivalents and marketable securities as of March 31 and said that should fund operations to the end of 2028.
Chief Executive Andrew Hirsch said in the May 12 release that C4 made “strong progress advancing cemsidomide” and was backed by a “strong balance sheet.” The same update showed a first-quarter net loss of $25.1 million, narrower than $26.3 million a year earlier, on revenue of $6.2 million. C4 Therapeutics, Inc.
Another support point is Roche. C4 and Roche expanded their collaboration in April to develop degrader-antibody conjugates, a newer class that links targeted antibodies with protein-degrading payloads. Reuters reported the deal could be worth more than $1 billion, and an SEC filing showed C4 received a $20 million upfront payment and may receive milestone payments and royalties.
Roche business-development head Boris Zaïtra called the partnership a “decade of trust and shared scientific ambition,” while Hirsch said the work combines C4’s degrader design with Roche’s antibody-drug conjugate experience. SEC
The trade sits inside a livelier niche of targeted protein degradation, where C4 is often watched alongside Arvinas, Kymera Therapeutics and Nurix Therapeutics. Early indications were not uniform: Arvinas slipped 0.9%, while Kymera rose 1.2% and Nurix gained 0.6%; the SPDR S&P Biotech ETF was up 0.8%.
But there is a hard risk case. C4 is still a clinical-stage company, meaning its main drugs are being tested and are not yet commercial products; thin premarket trading can exaggerate moves, and Nasdaq warns that extended-hours markets tend to have lower liquidity and higher volatility. A weak data readout, slower enrollment or delayed partner milestones could quickly pull the stock back from the highs.
For now, the market is trading the setup rather than a new approval or revenue inflection. The next few weeks will test whether C4 can turn conference attention and Roche validation into harder clinical momentum.
