Immunology is being rewritten: why this matters for global equity investors
Immunology’s $216bn market is changing shape, eroding incumbents’ pricing power and reshuffling winners and losers.
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Immunology, one of the largest global therapeutic drug markets, with annual revenues of $216 billion, is entering a new phase of disruption. Drug developers are moving beyond broad immune suppression toward genuine innovation in how common diseases – like psoriasis, for example – are treated. These include precision therapies, oral biologic-like medicines, combination regimens and potentially curative cell therapies.
The broader implication of this disruption is that immunology may increasingly resemble oncology: more personalised, mechanism-driven and potentially curative.
For investors, the story isn’t about the next “slightly better” drug, but the immunology market changing shape. As new oral and more targeted therapies arrive, revenues from established franchises may become less predictable. Today’s leaders may be easier to challenge.
The commercial stakes are high: treatment pathways could be reshaped, creating clear winners and losers. Likely winners are companies that can pair precise science with the convenience of pills (oral medicines designed to match the effectiveness of injectable biologic therapies, see below) and prove durable disease control in real-world use. The likely losers are those relying on ageing, injection-led products that struggle to defend share as switching becomes easier.
Global historic and forecast growth for top 20 therapy areas, constant US$ 2021-2030
Source: IQVIA Forecast Link, Dec 2025; IQVIA Institute, Dec 2025. Notes: Bubble size represents forecast in 2029; COVID-19 vaccines and therapeutics are not included. Analysis is based on disease attribution of sales by diagnoses. Proprotein Convertase Subtilisin/Kexin type 9 (PCSK9), a protein that regulates cholesterol by controlling LDL (bad) cholesterol receptors in the liver, and marketed drugs include antibody drugs for PCSK9 and small interfering RNA (siRNA) therapies. Report: Global Medicine Use Trends 2026: Therapy Drivers, Spending Levels, and Policy Evolution. IQVIA Institute for Human Data Science, February 2026.
Key investor considerations include:
- Defending today’s profits vs finding the next growth engine. Many older blockbuster immunology drugs are facing cheaper copycats (biosimilars) and stronger new rivals. Share prices may increasingly depend on which companies can replace those fading revenues with proven, late-stage new products that can scale globally.
- Ease of use can decide who wins. If new pills can match injections for long-term effectiveness and safety, they could be prescribed earlier and used by more patients. This could shift market share towards the companies with the best oral options.
- More competition means less pricing power. As more drugs target the same diseases in different ways, it may become harder to charge premium prices. Winning is likely to depend on which treatments show the most durable benefits, fewest side effects, simplest dosing, and strongest evidence in everyday use, as well as how they are positioned on insurer and health-system formularies.
- Combining drugs in inflammatory bowel disease (IBD) could reshape spending and strategy. In inflammatory bowel disease (ulcerative colitis and Crohn’s disease), doctors are increasingly exploring using two treatments together rather than switching one-by-one after failure. This could improve outcomes, but it also raises a key commercial question: will payers fund higher-cost combinations? Companies with broader portfolios (or the ability to partner/acquire) may be better placed if combinations become standard.
- One-off cell therapies are a long-term threat to the old business model. Early work in cell therapies suggests some patients might one day achieve long remissions after a single treatment. That’s still uncertain and likely limited at first, but it challenges the traditional model of lifelong, repeat-prescription medicines that has driven immunology profits for years.
What’s changing and why it matters
1) From injections to “biologic-like” pills
A central disruption within immunology is oral formats that aim to deliver biologic-level outcomes without injections. The prize is large: pills are easier to start, easier to stay on, and may be used earlier in the treatment pathway, potentially expanding the treated population while speeding up competitive share shifts.
Example: Johnson & Johnson’s recently approved oral IL‑23 pathway therapy in psoriasis (with broader development underway) is being closely watched because it tests a pivotal idea: can an oral option deliver durable, biologic-like control across multiple inflammatory diseases? If yes, convenience becomes both a clinical and commercial advantage and the switching pressure on injectable incumbents rises.
2) Higher efficacy standards in dermatology with ripple effects
Dermatology indications are increasingly shaping expectations for other inflammatory diseases because they generate large data sets and fast adoption when therapies outperform.
Example: UCB’s bimekizumab (Bimzelx), a prescription biologic medicine used to treat certain immune‑mediated inflammatory diseases, has raised efficacy expectations in psoriasis and has entered hidradenitis suppurativa (HS), an area with high unmet need. In HS, where choice has been limited historically, meaningful improvements can drive rapid prescribing change, creating opportunity for entrants and risk for incumbents reliant on older standards of care.
Innovation keeps pushing the efficacy frontier in psoriasis
Source: A.W. Armstrong, Comparative efficacy and relative ranking of biologics and oral therapies for moderate-to-severe plaque psoriasis, Dermatology and Therapy (Heidelberg), 2021; and A.W. Armstrong, Efficacy of bimekizumab and other biologics in moderate-to-severe plaque psoriasis: a systematic literature review and a network meta-analysis, Dermatology and Therapy (Heidelberg), 2022
3) IBD is moving towards combination regimens
In inflammatory bowel disease, the frontier is shifting from sequential cycling through therapies to combining mechanisms to achieve deeper remission and mucosal healing (i.e., aiming to control disease more completely, not just reduce symptoms).
Why it matters: combination strategies could reshape treatment sequencing, trial design and commercial strategy. However, their uptake may ultimately hinge on payer behaviour, specifically whether insurers and health systems will reimburse the higher total cost of multi‑drug regimens. It will also depend on whether “step therapy” policies (which require patients to try cheaper or standard options first) loosen or tighten, shaping how quickly and for whom combination treatments can be used.
4) TL1A: a potential new backbone mechanism — and a step towards precision
TL1A inhibition (immunology drug approach that aims to block a specific inflammatory signalling protein called TL1A) has emerged as one of the most important new mechanisms in IBD because it targets biology linked to chronic inflammation and fibrosis (scarring). The investment relevance is twofold:
- it could create a new branded growth vector in a crowded market;
- Over time, doctors may increasingly use measurable “biomarkers” (tests in blood, tissue, or genetics) to help choose the treatment most likely to work for a specific patient, rather than relying on trial and error. This tends to reward companies that can prove their medicine works best in a clearly defined patient subgroup and can support that claim with strong clinical evidence.
Industry interest is reflected in major deal activity (for example, Merck and Roche have both moved to secure TL1A assets), signalling the mechanism’s perceived strategic value.
5) CAR-T in autoimmune disease: early, but strategically disruptive
CAR‑T is being explored as an “immune reset” concept in severe autoimmune disease, the opposite of chronic suppression. Evidence is still early and scalability, safety, durability and cost are unresolved. But even limited success would introduce a new value model: high upfront cost in exchange for durable, drug-free control in selected patients.
Why it matters: it may not disrupt mainstream immunology revenues tomorrow, but it creates a credible long-term question over the ceiling for chronic maintenance economics in the most severe segments.
Conclusion
Immunology is still a big and profitable market, but the investment case is changing. It’s no longer just about backing companies with long-lasting blockbuster injection drugs. It’s about backing companies that can protect today’s profits and build the next generation of treatments that become the new standard of care. Winners are more likely to be those with (1) late-stage breadth across major indications, (2) credible oral and/or combination strategies, and (3) the commercial capability (and partnering discipline) to compete in a more segmented, payer-managed environment. Losers are those over-exposed to ageing mechanisms with weakening differentiation and increasing substitution risk.
Securities/sectors/regions mentioned are for illustrative purposes only and not a recommendation to buy or sell any security.
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