Eleven months, US$32.5 million turned into US$382.5 million

Three things must be made clear. The US$1.013 billion is the milestone cap, not an expected value; the announcement discloses neither how it is split nor the triggers. The cash actually received is only US$32.5 million, about 3% of the headline. The other half of the upfront is equity — and the number, percentage and lock-up of the shares Hengrui holds are likewise undisclosed, so one cannot assume that portion has appreciated just because the licensee priced above its range.

Key numbers per Hengrui’s announcement of 2025-09-05.

Line the dates up and the shape of the deal becomes clear.

Both readouts came after signing, about seven and eight months later respectively.

A fair word is needed here. At signing, public clinical evidence went only as far as Phase 1; the licensee bore the full risk that Phase 2 might disappoint, and that risk is anything but hypothetical in this class — BMS’s mavacamten Phase 3 ODYSSEY-HCM in the non-obstructive population announced on April 14, 2025 that it had missed its 48-week dual primary endpoints. Risk transfer has a price. Saying “it was sold too cheaply” after seeing good data is classic hindsight.

Set the deal structure aside and look at the molecule first.

Its mechanism risk has already been cleared by others. The cardiac myosin inhibitor class has been validated through two registrations: mavacamten is the world’s first, aficamten the second, the latter approved in China in December 2025 and in the EU in February 2026. The buyer doesn’t need to pay for “can this mechanism become a drug” — the layer of value most easily underestimated for this kind of Chinese asset overseas.

Its clinical execution is also genuinely fast. In the Phase 1 study presented at ESC Congress 2025, by day 5 of dosing obstructive patients’ resting LVOT gradient fell by an average of 91.0%, from 71.2 mmHg to 6.0 mmHg; the Valsalva gradient fell 87.4%, from 66.6 mmHg to 8.0 mmHg. Pharmacokinetically, steady state was reached by day 8. Dose-related ejection fraction declines were observed in healthy subjects, on which basis the investigators set 60 mg as the starting dose for patients.

By August 2026 the molecule had accumulated in China 76 patients in Phase 1, 42 in the obstructive Phase 2, 84 in the non-obstructive Phase 2, 216 in Phase 3 and 300 in a long-term safety study, plus four pharmaceutics and clinical pharmacology studies: verapamil interaction, food effect and relative bioavailability, human mass balance, and bioequivalence between two formulations. This package is on the solid end for a domestic Class 1 innovative drug, and explains why the buyer dared to sign with only public Phase 1 data.

The differentiation claim is “fast onset, little or no dose titration”. The claim holds up pharmacokinetically, but so far no head-to-head study supports it being better than the two incumbents. It is more a selling point awaiting validation than an established advantage.

One thing deserves separate attention: the bioequivalence study between the two formulations only started on April 14, 2026, with 58 subjects and expected primary completion in July. This indicates a change between the formulation used in clinical studies and the one intended for commercialization, with bridging scheduled before the Phase 3 readout. This is standard practice, but it is still unfinished homework.

The license territory has only one dividing line: mainland China, Hong Kong, Macau and Taiwan versus the rest of the world. The US, Europe, Japan and emerging markets are not separated, no self-commercialization option is reserved for any region, and there is no split by indication. The announcement likewise makes no mention of reversion clauses, diligence obligations or joint governance.

This means that from the day of signing, Hengrui has only three passive channels in the molecule’s ex-China part: milestones, sales royalties and its equity stake. How development is paced, how the dosing regimen is set, which indication goes first, when to file — none of these are decisions it can take part in anymore.

What bundling bought was speed and the execution certainty of a single counterparty. The cost was that the chance of a second pricing went to zero.

There is another easily overlooked consequence. The license scope explicitly includes manufacturing, and a technology transfer payment of up to US$10 million is arranged — a direct signal that the supply relationship may move outside. “The licensee has manufacturing rights” does not equal “finished product will necessarily be made by Hengrui”; once technology transfer is complete, Hengrui’s irreplaceability in the overseas supply chain will decline. Long-term income from this cannot be taken for granted.

Another open question is indications. The announcement splits by territory, not by indication. The heart failure with preserved ejection fraction line — the Chinese Phase 2 only started on March 30, 2026, with 48 patients and registered primary completion in March 2027 — hadn’t even begun when the deal was signed. This indication’s patient population is an order of magnitude larger than hypertrophic cardiomyopathy, and no molecule in this class has yet staked a claim there. Who holds its ex-China rights must be determined from the agreement text, and cannot be assumed from the single phrase “global rights outside Greater China”.

Hengrui itself said in the announcement that this was its “second collaboration with international investment institutions in less than 18 months”. Lining up its going-global track record makes it more interesting.

Amounts in US dollars. “Upfront” is the consideration at signing as disclosed in the announcement (including any equity portion); “milestone cap” is the disclosed cap, not an expected value, and most triggers are undisclosed.

Aiolos is the extreme reference: it took the license in August 2023, and on January 9, 2024 GSK announced it would acquire the company for US$1 billion upfront plus up to US$400 million in regulatory milestones, closing on February 14. About five months in between.

Kailera is the positive example: Hengrui received an initial 19.9% equity stake, the core asset has entered global Phase 3, and the licensee priced its IPO at US$16 in April 2026, raising about US$625 million.

By comparison, the main drivers of the upfront differences are data maturity and the nature of the buyer, not molecule quality. The deal with a multinational carried a US$500 million upfront; the deals with newly founded companies were all in the tens of millions. And on the NewCo route, what really determines the seller’s long-term return is not the upfront but the equity stake — the only part that can appreciate along with the asset.

On May 5, 2026, Cytokinetics announced that aficamten’s Phase 3 ACACIA-HCM in non-obstructive hypertrophic cardiomyopathy met its dual primary endpoints: 516 patients, at week 36, a between-group difference of +3.0 in the Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (p=0.021) and +0.67 mL/kg/min in peak oxygen uptake (p=0.003).

That was six days before HRS-1893’s non-obstructive Phase 2 results were released.

The non-obstructive indication was once seen as the biggest open space in this class. Mavacamten failed there; aficamten succeeded. This means the position of “first to prove efficacy” is now taken, and from that day any description of non-obstructive disease as a gap this asset could fill no longer holds.

That, conversely, is the challenger’s only remaining opportunity — but it must be proven by a precisely designed Phase 3, not by one attractive Phase 2.

Hengrui kept Greater China, and that part is entirely its own. But the math must be clear.

Mavacamten was approved in China in 2024 and entered the NRDL, effective January 1, 2025. Aficamten was approved on December 17, 2025 for adult obstructive patients in New York Heart Association class II to III, and its Greater China rights were acquired by Sanofi from Everest Medicines in December 2024. HRS-1893’s Chinese Phase 3 has a registered primary completion date of September 2026; on a normal timeline, launch would land around 2028.

Two things can still be played. The cost structure of an oral small molecule supports trading price for volume; and Hengrui’s cardiology team has already been built for recaticimab (Aixin’an®), so a network of more than 25,000 hospitals can be reused directly, with very low marginal selling cost for adding another small-population product. That is not enough to retake first place, but it is enough to hold a sustainable share.

There are three real validation points ahead, all observable from public information: