Are GLP-1s on the verge of becoming pharma’s biggest segment?
Yes and no. It depends whether you’re watching products or categories. And in terms of individual drugs, it likely depends on the year. Oncology is still on top for now.
On the product level, according to Evaluate’s 2028 projections, Keytruda will maintain its lead at approximately $30 billion, with Mounjaro and Ozempic each reaching about $17 billion. However, the crossover, the year when it draws even and later ahead, could happen by 2030. Evaluate projects Mounjaro will become the world’s top-selling drug at $36 billion that year, while Keytruda drops to $17 billion as it faces U.S. IRA price negotiations (effective January 1, 2028) and a patent cliff in December 2028. EU market exclusivity is expected to end in 2031, according to Reuters.
As a class, the top five GLP-1s are already bigger than oncology heavyweights Keytruda and Darzalex, the second-largest oncology drug. In 2024, the five leading GLP-1s generated $46.1 billion, surpassing Keytruda’s $29.5 billion by $16.6 billion, and topping the combined $41.2 billion from those two oncological therapies.
Oncology still bigger, but GLP-1 growth faster
Oncology still dwarfs GLP-1s overall. According to Fortune Business Insights, the oncology drug market was valued at around $220 billion in 2024 and is projected to hit $518 billion by 2032. Meanwhile, according to Grand View Research, the GLP-1 market stood at roughly $53 billion in 2024 and is forecast to reach $157 billion by 2030.
Unsurprisingly, GLP-1s are growing faster: 17.5% annually versus 11.3% for oncology, but from a much smaller base. More telling: the GLP-1 surge is concentrated in a handful of products—chief among them are Ozempic, Wegovy, Mounjaro, Zepbound, and Rybelsus.
Oncology, by contrast, has broad depth. Dozens of brands clear $1B annually; in 2024, according to Merck, Keytruda generated about $29.5B in revenue. Genmab reported Darzalex reached about $11.7B, and according to Bristol Myers Squibb, Opdivo achieved $9.3B.
Oncology’s breadth is its strength. Modalities span checkpoint inhibitors, ADCs, CAR-T and targeted small molecules, with pipelines in protein degraders and bispecifics. Big Pharma is still piling in: Pfizer closed its 2023 $43B Seagen deal to expand its ADC platform, and PD-1 biosimilars are expected to arrive late-decade, expanding access rather than collapsing the category, as CRA Insights noted.
GLP-1 growth cooling though
GLP-1s, meanwhile, face headwinds. Goldman Sachs now models a $95B 2030 market (down from $130B), citing pricing pressure, uncertain Medicare coverage and persistence questions.
According to JAMA Health Forum, average net costs reach $700–$800/month and current prices exceed cost-effectiveness thresholds.
Persistence remains mixed: a 2024 real-world study found 32% on therapy at 1 year among non-diabetic users, and according to Prime Therapeutics, only 1 in 12 remain at 3 years. Supply has improved and the FDA has scaled back compounding; at the same time, cash-pay options have emerged (e.g., Wegovy $499/month via NovoCare; Lilly’s Zepbound self-pay vials at $499), while list prices remain around $1,000+.
The oral wave could change the math, but it’s not a lock. Lilly’s orforglipron, a once-daily pill, posted Phase 3 wins in T2D and obesity: according to the New England Journal of Medicine, in a head-to-head T2D study, orforglipron cut A1C by 2.2% vs 1.4% for oral semaglutide; a separate obesity study showed approximately 12.4% weight loss at 72 weeks.
Oral GLP-1s could fuel more growth
Lilly has signaled regulatory filings beginning 2025–2026, with a global rollout that includes markets like India where tablet preference could widen access, according to Reuters. Orforglipron’s no-cold-chain logistics may push more starts through primary care and expand ex-U.S. uptake (not just cannibalize injectables).
Street estimates cluster around $10–$13.5B by 2030 (Reuters/consensus about $10B; according to FiercePharma citing Evaluate, approximately $12.7B; Visible Alpha consensus around $10B; Leerink $13.5B). An illustrative ramp might show $2–$4B (2026), $6–$9B (2027), $9–$12B (2028), with upside if adherence and pricing cooperate.
Next-gen GLP-1s could raise the ceiling. According to Reuters, Novo’s amycretin (GLP-1+amylin) showed up to 22–24% weight loss (inj.) and 13% in an oral study, with Phase 3 slated for 2026. According to Evaluate, Lilly’s retatrutide (GLP-1/GIP/glucagon) hit 23–24% in Phase 2, with 2030 sales modeled around $5.6B.
What all of this could mean for the Keytruda crossover
According to Evaluate’s consensus forecast, Keytruda maintains its crown through 2028 at approximately $30 billion, with Mounjaro trailing at $17 billion. The inflection point arrives in 2029-2030, when Mounjaro surges to $36 billion while Keytruda drops to $17 billion due to biosimilar competition and IRA pricing pressures. Oral GLP-1 launches and stronger-than-expected persistence could accelerate the timeline slightly; payer resistance or manufacturing constraints could extend it.
When Mounjaro overtakes Keytruda around 2029-2030, that’s a product-versus-product milestone driven as much by Keytruda’s U.S. loss of exclusivity as GLP-1 velocity. By 2030, Evaluate projects five GLP-1s in the top 10 (Mounjaro $36B, Zepbound $25.5B, Ozempic $24.4B, Wegovy $18.1B, plus Cagrisema $15.2B), reshaping metabolic disease with concentrated mega-blockbusters. Meanwhile, oncology remains the largest therapy area in 2030, with over $370 billion in forecast product sales across dozens of $1B-plus drugs, diverse mechanisms, and deep pipelines. It’s a rebalancing, not a regime change.
Filed Under: Metabolic disease/endicrinology, Oncology
