Novartis' Cosentyx and the Polymyalgia Rheumatica Opportunity: A Strategic Investment Analysis

In October 2025, Novartis announced a landmark achievement for its blockbuster biologic Cosentyx (secukinumab): the drug met both primary and all secondary endpoints in the Phase III REPLENISH trial for polymyalgia rheumatica (PMR), a condition affecting over 1 million adults aged 50 and older globally, according to a Novartis press release. This success positions Cosentyx as a potential game-changer in a market long dominated by corticosteroids, which, while effective, carry significant long-term risks such as osteoporosis and hypertension, according to a Market.us report. For investors, the question is whether this therapeutic differentiation and the unmet medical need in PMR can translate into durable stock growth for Novartis.

Therapeutic Differentiation: A Novel Approach to PMR

The REPLENISH trial demonstrated that Cosentyx achieved statistically significant sustained remission at Week 52 compared to placebo, with a 60% reduction in annual cumulative steroid dose for patients. This is a critical advantage in PMR, where corticosteroid tapering is notoriously challenging. By targeting interleukin-17A (IL-17), a cytokine central to inflammatory pathways, Cosentyx offers a mechanism distinct from existing biologics like IL-6 inhibitors (e.g., sarilumab), as noted in a ScienceDirect review. The drug's safety profile, consistent with its established use in psoriasis and psoriatic arthritis, further strengthens its appeal, according to the Cosentyx safety page.

Market Opportunity: A Growing Pie with High Unmet Need

The PMR treatment market is projected to grow at a compound annual growth rate (CAGR) of 14.1% from 2025 to 2032, expanding from $303.5 million to $764.1 million, according to a CoherentMI report. This growth is driven by an aging global population and rising awareness of PMR's complications, such as giant cell arteritis (GCA). Cosentyx's ability to reduce steroid dependency directly addresses a key unmet need: approximately 30% of PMR patients experience relapses within a year of tapering steroids, according to a Morningstar article. With a 24-week steroid taper regimen demonstrated in the REPLENISH trial, Novartis could capture a significant share of this market, particularly as biosimilars for existing biologics enter post-2027, per a Mordor Intelligence report.

Stock Valuation: Balancing Optimism and Risks

Analyst ratings for Novartis remain mixed, with a consensus price target of $123.54-slightly below the current stock price of $126.76, according to StockAnalysis ratings. While some institutions like Morgan Stanley have upgraded the stock to "Equalweight," others, including UBS, have downgraded it due to patent expiry risks for Cosentyx and other key drugs, according to the MarketScreener consensus. However, the PMR approval could mitigate these concerns. Cosentyx's 2024 revenue of $3.5 billion is projected to grow to $6.8 billion by 2033, with PMR contributing a meaningful portion, per a QYResearch forecast. The drug's lifecycle management strategies, including device upgrades and new indications, also aim to counter biosimilar competition, as discussed in a LinkedIn analysis.

Strategic Implications for Investors

The Phase III success in PMR adds a high-margin, differentiated asset to Novartis' portfolio, which is critical as the company transitions from older products like Gilenya. However, investors must weigh this against near-term challenges, such as the GCAptAIN trial's failure for giant cell arteritis and the broader biologics market's competitive intensity. For long-term growth, the key will be Novartis' ability to secure regulatory approval (expected in H1 2026) and demonstrate cost-effectiveness to payers in a market where corticosteroids remain the standard of care, according to a Pharmaphorum article.

In conclusion, while the stock's valuation reflects caution, the therapeutic and market potential of Cosentyx in PMR offers a compelling catalyst. For investors with a 5–10 year horizon, this could represent a strategic inflection point for Novartis.