Phase 3 trials to watch in 2025: Why this year matters for biotech investors

In the global biotech landscape, Phase 3 clinical trials represent the final proving ground before regulatory approval. In 2025, several high-profile trials are underway that could reshape market capitalisation, pipeline positioning, and therapeutic leadership for companies such as Innovent Biologics, Eli Lilly and Company, and GSK. From breakthrough oncology drugs to rare disease treatments, these pivotal trials are more than just scientific milestones—they’re stock catalysts.

For investors, fund managers, and analysts tracking late-stage biotech momentum, these trials are worth watching not only for their clinical significance but for their potential to unlock billions in addressable market value and drive portfolio reratings.

What Is Innovent Biologics’ IBI354 Targeting in Phase 3?

Innovent Biologics has made headlines in 2025 with the progression of IBI354, an anti-HER2 antibody-drug conjugate (ADC) targeting platinum-resistant ovarian cancer. The trial, named HeriCare-Ovarian01, is a randomized, multicenter Phase 3 study—reportedly the first in China focused specifically on HER2-expressing ovarian malignancies in this subgroup.

As the first Chinese-origin ADC in late-stage ovarian oncology, IBI354 represents not only a scientific milestone but a strategic pivot for Innovent. If successful, it positions the company as a regional innovator in HER2-targeted therapeutics—a space historically dominated by Western pharma.

Investor sentiment remains bullish following early safety and efficacy signals. Analysts suggest that a successful trial could enable out-licensing deals, first-in-class approval by the NMPA, and potentially trigger FDA Breakthrough Therapy Designation for global expansion. For a company already partnered with Eli Lilly in other programs, IBI354 could be a platform-defining asset.

How Is Eli Lilly Leveraging Its Oncology and Obesity Pipelines in Phase 3?

Eli Lilly and Company continues to expand its Phase 3 presence across oncology and metabolic disorders, including breast cancer and obesity—two of the most competitive therapeutic areas globally.

In breast cancer, Lilly is advancing the EMBER-3 trial, evaluating imlunestrant, an oral selective estrogen receptor degrader (SERD), in ER-positive, HER2-negative postmenopausal patients. This drug enters a crowded field dominated by AstraZeneca’s Faslodex and other injectable SERDs. However, imlunestrant’s oral formulation and strong tolerability could improve adherence and market uptake.

In parallel, orforglipron, Lilly’s oral GLP-1 receptor agonist, is in Phase 3 development for weight management and type 2 diabetes. Early Phase 2 data showed metabolic efficacy on par with injectable GLP-1s like semaglutide (Wegovy), but with better patient compliance potential. Analysts estimate the obesity drug market could exceed $100 billion by 2030, with oral GLP-1s opening access to new patient demographics.

With Lilly’s stock already reflecting momentum from tirzepatide (Zepbound), investors are closely watching the timeline for orforglipron’s FDA submission. A strong Phase 3 readout in 2025 could trigger upward earnings revisions and further institutional inflows.

What Are GSK’s Pivotal Phase 3 Assets in 2025?

GSK plc has taken a differentiated approach in its Phase 3 pipeline for 2025, focusing on rare diseases and immunology—two areas with unmet needs and favourable pricing environments.

One of the company’s most promising assets is linerixibat, tested in the GLISTEN Phase 3 trial for primary biliary cholangitis (PBC), a rare liver disease. The drug has shown significant improvement in cholestatic pruritus, a debilitating symptom in PBC patients. If approved, linerixibat could be GSK’s lead orphan asset in hepatology.

Another standout is depemokimab, an anti-IL-5 long-acting monoclonal antibody being evaluated in ANCHOR-1 and ANCHOR-2 Phase 3 trials for chronic rhinosinusitis with nasal polyps (CRSwNP). Inflammatory airway diseases remain a focus for GSK, and depemokimab could compete directly with Sanofi–Regeneron‘s Dupixent in this niche.

What sets GSK apart in 2025 is not just pipeline breadth but the regulatory momentum behind its orphan programs. Both linerixibat and depemokimab have received Fast Track designations, and analysts expect rolling submissions to begin in late 2025.

Why 2025 Is a Pivotal Year for Phase 3 Trials Across Biotech

Several macro factors are influencing the volume and visibility of Phase 3 programs this year. These include accelerated regulatory pathways for high-impact assets in oncology and rare diseases, the use of AI-driven trial design and adaptive protocols that improve time-to-readout, R&D reprioritisation post-2023 funding corrections, and an uptick in strategic licensing and M&A potential, with Big Pharma actively scouting for late-stage pipeline additions.

As interest rates stabilise and capital flows return to the sector, positive Phase 3 data can become immediate value unlocks, driving dealmaking, partnership revenue, and valuation rerates.

What Are the Financial Implications for Investors?

For Innovent Biologics, a successful IBI354 readout opens up not only NMPA approval but potential dual filings in the U.S. and Europe. It could also trigger follow-on oncology pipeline expansions or collaborative trials.

For Eli Lilly, the success of orforglipron and imlunestrant represents a double-barrelled catalyst: consolidation of its metabolic leadership and revival of its breast cancer pipeline. Analysts from Morgan Stanley project that orforglipron alone could generate $5–7 billion in peak annual revenue, depending on payer acceptance and formulary access.

GSK’s focus on rare indications allows it to target high-margin verticals with minimal competition. If linerixibat is approved, the company could carve out a sustainable niche in rare hepatology, backed by pricing power and regulatory exclusivity.

What Should Investors Watch for in the Next Two Quarters?

The upcoming readout calendar for these trials spans from Q3 2025 to early Q1 2026, with several interim updates expected during major industry conferences including ASCO 2025 for oncology, EASL Congress for liver diseases, and Obesity Week for GLP-1 trials. Regulatory signals such as Breakthrough Designations, Priority Reviews, and Rolling Submissions will be key inflection points. Investors should track sponsor press releases, analyst upgrades, and FDA or EMA portal updates.

Outlook: Where Biotech Investors Should Focus in 2025

As 2025 unfolds, Phase 3 trials will not only determine drug approvals but shape which companies emerge with stronger strategic pipelines and commercial leverage. Innovent could solidify its position as China’s leading global-facing biotech. Eli Lilly may extend its dominance in both oncology and metabolic health. GSK could finally deliver pipeline-driven margin expansion after a long period of underperformance. For institutional and retail investors alike, this is the year to watch the data — and move before the rerating curve hits its peak.