TD Cowen analyst Yaron Werber has designated Relay Therapeutics as his top small- to mid-cap investment idea, singling out the company’s lead investigational therapy, zovegalisib (RLY-2608), as the primary driver behind his view.
Werber has reiterated a Buy rating on Relay, emphasizing zovegalisib’s combination of efficacy and tolerability as a competitive advantage in PIK3CA-mutant metastatic breast cancer. The analyst highlights data showing the zovegalisib plus fulvestrant regimen delivered a median progression-free survival (PFS) of 11.1 months at the pivotal dose in the second-line and later setting. That outcome, Werber notes, meaningfully exceeds the PFS figures associated with currently approved comparators cited in the data: Truqap plus fulvestrant at roughly 5.5 months and Piqray plus fulvestrant at roughly 7.4 months.
The safety profile reported for the combination is a central part of Werber’s thesis. Zovegalisib demonstrated low rates of Grade 3 hyperglycemia, rash, and diarrhea in the cited data, outcomes that the analyst views as differentiating features likely to support broad adoption.
The drug is advancing into a head-to-head Phase 3 study. The ReDiscover trial pits zovegalisib plus fulvestrant directly against the current standard of care, Truqap plus fulvestrant. Werber reports that key opinion leaders he consulted express strong confidence the trial will succeed, with expectations of median PFS in the 9-12 month range. Based on those views, Werber anticipates zovegalisib could secure the majority share of the PIK3CA-mutant second-line metastatic breast cancer market, a population that represents approximately 35% of second-line metastatic breast cancer and an estimated U.S. total addressable market of $2-3 billion.
Relay is also developing zovegalisib for earlier lines of therapy. The company is testing a triplet regimen that adds zovegalisib to fulvestrant and Pfizer’s CDK4 inhibitor atirmociclib in the first-line setting. Early clinical readouts showed a 44% objective response rate alongside a favorable safety profile. Management has outlined plans to start a Phase 3 trial in early 2027, a step that would position zovegalisib to compete in a substantially larger first-line market estimated at $7-8 billion in the U.S.
Beyond breast cancer, Werber identifies an opportunity in vascular anomalies that he believes is underappreciated. Initial results from the Phase 2 ReInspire study reported a 60-65% vascular response rate at 12 weeks, markedly higher than the 11-16% benchmark cited by the analyst. Based on those data, Werber sees a clear pathway toward accelerated approval in this indication, which he values as representing a $6-8 billion total addressable market.
Key points
- TD Cowen reiterates a Buy on Relay Therapeutics, identifying zovegalisib as a potential best-in-class PI3Kα inhibitor for PIK3CA-mutant metastatic breast cancer.
- Zovegalisib plus fulvestrant showed 11.1 months median PFS at the pivotal dose in second-line and later disease, versus approximately 5.5 months for Truqap and 7.4 months for Piqray in cited comparisons.
- Relay is pursuing multiple market opportunities: second-line and first-line breast cancer regimens and vascular anomalies, with U.S. TAM estimates cited at $2-3 billion, $7-8 billion, and $6-8 billion respectively.
Risks and uncertainties
- Phase 3 outcome uncertainty - The ReDiscover head-to-head trial against Truqap plus fulvestrant is ongoing, and its final results will determine regulatory and commercial outcomes.
- Regulatory pathways - Accelerated approval in vascular anomalies is a pathway highlighted by the analyst, but it remains contingent on further clinical and regulatory review.
- Competitive dynamics - Although Werber notes that competitive risk from Caelum Biosciences’ gedatolisib appears reduced following recent data, the broader competitive landscape remains a factor for market share and adoption.
This analysis is centered on clinical data presented and the market assumptions outlined by the analyst. It reflects the views and projections cited by Yaron Werber and associated key opinion leaders as reported.