Corcept's ROSELLA Study Breakthrough: Relacorilant Achieves Dual Ovarian Cancer Endpoints

Corcept Therapeutics made headlines on January 22 when its experimental drug relacorilant met a crucial survival milestone in the ROSELLA study, sending shares soaring 13.7%. The phase III ROSELLA study evaluated relacorilant combined with nab-paclitaxel against platinum-resistant ovarian cancer, demonstrating what many view as a landmark achievement in this difficult-to-treat indication. This success comes as a significant relief following recent regulatory challenges with the company’s lead marketed product.

ROSELLA Study Breakthrough: Dual Primary Endpoints Met in Platinum-Resistant Ovarian Cancer

The ROSELLA study’s success hinges on achieving both primary endpoints—progression-free survival (PFS) and overall survival (OS)—without requiring biomarker selection or imposing additional safety burdens on patients. This represents a meaningful advancement, as simultaneously clearing dual endpoints remains relatively uncommon in late-stage oncology trials.

The OS data proved particularly compelling. Patients receiving relacorilant plus nab-paclitaxel achieved a median survival of 16 months, compared to 11.9 months in those treated with nab-paclitaxel alone. This translates to a 35% reduction in death risk—a substantial clinical benefit for a patient population with limited therapeutic options. Last April, the ROSELLA study had already demonstrated superiority in the PFS endpoint as assessed by blinded independent central review (PFS-BICR), reinforcing the consistency of the combination’s efficacy.

Clinical Data Deep Dive: Relacorilant’s Survival Benefits and Safety Profile

What distinguishes the ROSELLA findings is not merely the efficacy signal but the favorable tolerability data accompanying it. The relacorilant plus nab-paclitaxel combination demonstrated a safety profile comparable to historical benchmarks, with no unexpected adverse events or increased treatment burden. This balance between efficacy and tolerability makes relacorilant particularly attractive for a patient population already facing aggressive chemotherapy.

The 4.1-month improvement in median OS, though modest in absolute terms, holds considerable clinical significance given the disease’s poor prognosis and limited prior treatment options. For platinum-resistant ovarian cancer patients—those whose disease recurs within six months of completing platinum-based chemotherapy—the ROSELLA results may reshape treatment paradigms.

Regulatory Pathway and Future ROSELLA-Based Trials

The FDA’s acceptance of relacorilant’s new drug application (NDA) in September 2025 sets the stage for regulatory decision-making. The agency is expected to issue a determination on July 11, 2026, though this timeline may shift depending on additional interactions. Meanwhile, the European Medicines Agency received a marketing authorization application for the same indication, with a European decision anticipated later in 2026.

Beyond the core ROSELLA indication, Corcept is actively pursuing additional research avenues. The phase II BELLA study is evaluating a triple-drug regimen: relacorilant plus nab-paclitaxel alongside Roche’s Avastin (bevacizumab) in platinum-resistant ovarian cancer patients. This trial will help determine whether adding a second mechanism—bevacizumab’s anti-angiogenic effects—provides additional therapeutic value. Relacorilant is also being investigated across a broader oncology portfolio, including platinum-sensitive ovarian cancer, endometrial, cervical, pancreatic, and prostate malignancies.

The Cushing’s Syndrome Setback and Its Market Implications

Despite the ROSELLA momentum, recent events have tempered investor enthusiasm. In December 2025, the FDA issued a complete response letter (CRL) regarding relacorilant’s application for treating hypercortisolism (Cushing’s syndrome). Though the GRACE study met its primary efficacy endpoint and the confirmatory GRADIENT study supported those findings, the FDA determined that additional effectiveness evidence was necessary before determining that benefits outweigh risks.

This regulatory setback carries strategic implications. Relacorilant was positioned as potentially diversifying Corcept’s pipeline beyond its sole approved product, Korlym (used for Cushing’s syndrome). The delay in the hypercortisolism indication means Corcept remains heavily dependent on Korlym’s commercial performance. The drug generated $559.3 million in sales during the first nine months of 2025, representing 13.4% year-over-year growth—solid performance but insufficient to offset pipeline concerns.

Stock Performance and Investor Sentiment

The contrast in trajectories is striking. While CORT shares climbed 13.7% on the ROSELLA news, this barely reverses months of underperformance. Over the past six months, Corcept stock has declined approximately 40%, significantly lagging the broader industry’s 2.9% decline. This suggests that markets are pricing in substantial uncertainty about both the Cushing’s syndrome pathway and the commercial prospects for relacorilant in oncology.

Successful FDA approval in platinum-resistant ovarian cancer would represent a pivotal moment for Corcept, validating the relacorilant platform and potentially opening doors in other malignancies under study. Conversely, a rejection or conditional approval could reinforce concerns about the molecule’s viability beyond its initial conception as a glucocorticoid receptor antagonist for endocrine disorders.

Looking Forward: ROSELLA Data as a Catalyst

The coming months will be critical for Corcept shareholders. With the FDA decision on relacorilant’s ovarian cancer application expected mid-2026, investor focus will intensify on regulatory outcomes and the commercial strategy for launching this indication if approved. The ROSELLA study’s dual-endpoint success provides a compelling foundation, but regulatory approval remains the decisive factor. Simultaneously, data from the BELLA trial involving the three-drug combination and results from other solid tumor indications will shape the long-term value proposition of the relacorilant platform.