1. Cliff timing | Lilly's nearest exclusivity losses are
small and legacy. Trulicity (dulaglutide, $4.3B and already declining as patients migrate to Mounjaro) faces its main US patent expiry around
2027; Jardiance (empagliflozin, partnered with Boehringer Ingelheim) around
2029; and Cyramza (ramucirumab) is the single nearest event at
2026, but it is a mature, sub-scale oncology biologic. None of these is franchise-defining. The assets that actually drive the equity, tirzepatide-based Mounjaro and Zepbound, hold composition-of-matter and formulation protection to roughly
2036 in the US, 2037 in the EU and 2040 in Japan. On ABI's cliff axis, the share of revenue genuinely at risk inside the next three years is in the
low-single-digit percent range, an unusually clean profile for a company this size.
2. Concentration is the real exposure | The mirror image of the long runway is intensity. Roughly
65% of total revenue and a far larger share of the growth rides a single molecule class (the incretins), and within that, effectively one molecule (tirzepatide) plus its oral successor. The 2036 cliff is distant, but because it is so concentrated, the eventual event is
franchise-level rather than product-level: there is no portfolio of mid-size drugs to cushion it. Equally, the risk between now and 2036 is less "patent" and more
competitive and clinical, a Novo efficacy leapfrog, an obesity-share loss, a safety signal, or manufacturing slippage would impair the franchise long before any patent does. The cliff signal here should be read alongside the concentration flag, not in isolation.
3. The IRA / pricing overlay | A patent table understates the erosion calendar because US drugs now face a second, earlier clock: Medicare price-setting under the Inflation Reduction Act, plus the negotiated Most-Favored-Nation package. Jardiance is already in the first negotiated-price cohort (effective 2026); Trulicity and, prospectively, Verzenio sit in the at-risk set for subsequent cycles. The practical effect is that Lilly's older cardiometabolic and oncology lines see a
low-to-mid-teens price headwind that bites several years ahead of the formal patent date, while the incretins themselves carry a structural self-pay and access debate. ABI treats this as a soft cliff layered on top of the hard one.
4. Oncology read-across | In ABI's
Biosimilar Cliff (Oncology) signal, Lilly screens
clean, low biosimilar exposure against a high multiple. Its oncology franchise is largely small-molecule (Verzenio to 2031, Jaypirca to 2037, olomorasib in development) or long-dated, so it is not a near-term biosimilar target the way a large antibody portfolio would be. The one legacy biologic, Cyramza, is small. This is the segment where Lilly looks
least like the cliff universe and most like a durable grower.
5. Replacement optionality | The defining feature is that the pipeline is engineered to
push the cliff out, not just backfill it. Orforglipron (oral GLP-1, launched obesity-first as Foundayo) opens a manufacturing-scalable, ex-US-addressable leg; retatrutide (triple agonist, ~25-28% weight loss) and eloralintide (amylin) deepen efficacy; and the Lp(a) program (lepodisiran, muvalaplin) opens an entirely new cardiovascular category. Each of these is patent-protected into the late 2030s and beyond. This is the rare name where the cliff signal is dominated by
replacement upside rather than erosion risk.
