Payload-Linker 'Very Tight', Peptides Sold Out for 2027, Antibodies Just Cleared PAI: Asymchem Lays Out Its Capacity Gaps

At a 23 October investor call with more than 500 attendees (18 institutions filed records), Asymchem addressed capacity line by line: existing peptide capacity will run at high utilisation in 2027 with new build planned; payload-linker capacity is "very tight" and expansion is accelerating; antibody and fusion-protein orders surged in Q3, the site cleared a PAI inspection and enters commercial production in 2027 with a two-year capacity gap; Q3 new orders grew about 30% on a high base, with full-year guidance of 19%–22% unchanged.

On 23 October Asymchem hosted a specific-object investor call attended by CICC, Guojin Securities, Zheshang Securities, Huatai Securities, Guosheng Securities and others, with more than 500 participants; 18 institutions filed records. The value of the session was not financial — the Q3 report had already been published on the evening of 22 October — but that for the first time the company laid out, line by line, exactly where capacity is short.

Split the answers by business line and a fairly precise gap table appears.

The gap table: four lines, four degrees of tightness

Peptides: existing capacity will operate at relatively high utilisation in 2027, and new peptide capacity will be planned based on backlog and business development, with details to follow in the annual report. This is the language of "tight, but with headroom".

Payload-linker: the company used the words "very tight" and confirmed it is accelerating construction of new capacity. This is the strongest wording of the four lines and the most typical bottleneck in the ADC chain — toxin and linker capacity is jointly constrained by high-potency (OEB) suites, containment infrastructure and safety approvals, so the expansion cycle is far longer than for an ordinary small-molecule plant.

Antibodies and fusion proteins: orders growing rapidly, with Q3 particularly strong; the site cleared a PAI (pre-approval inspection) dynamic inspection in Q3, meaning commercial production begins in 2027; capacity will remain short for the next two years and expansion is required. This is the most informative line, because clearing PAI is not a quality event but a revenue event: it upgrades a line from "can take clinical batches" to "can take commercial launch volumes".

Drug product: capacity needs to increase further as formulation business commercialises and overseas projects multiply. Over the past two years the company has added substantial commercial fill-finish capacity — cartridges, prefilled syringes, blow-fill-seal — and has begun taking late-stage projects.

Taken together, Asymchem's capacity structure has shifted from "small-molecule reactors" to "four non-interchangeable lines, each short in its own way". That explains how a CDMO can grow revenue around 20% while running capex in four directions at once: it is not operating in one capacity market but in four.

Integrated ADC: what one PAI clearance actually means

One fact from the call deserves separate recording: the project that cleared PAI in Q3 was itself an end-to-end ADC programme running from payload-linker through antibody to final drug product.

That single sentence connects two things. The first is a closed capability loop — the company entered ADC through payload-linker, and can now string toxin-plus-linker, antibody, conjugation and drug product into one delivery chain. The second is customer mix — overseas orders already account for more than 50% of the ADC segment, with more revenue to come from overseas; as antibody, conjugation and DC drug-product work advances, integrated programmes keep increasing, with both customer count and integrated deliveries growing quickly.

For customers, integration means fewer interfaces and shorter release cycles. For the CDMO, it means higher switching costs and capacity locked earlier. When a single line can take both payload-linker and DC drug product, a customer's cost of moving is not changing supplier but repeating a technology transfer and regulatory filing.

Order side: +30%, a heavy fourth quarter, a better 2027

The same call produced three statements on orders. First, Q3 new orders grew at a double-digit rate year on year — about 30% — against a high prior-year base; chemical macromolecule and biological macromolecule orders grew rapidly, and small-molecule new orders improved markedly over the first nine months. Second, the Q4 delivery load is very heavy, "genuinely challenging", and the company will do everything to protect delivery while remaining confident of hitting full-year reported revenue growth of 19%–22%. Third, looking to 2027, based on new order growth, backlog value and segment development, revenue growth is expected to accelerate from 2026.

On quarterly phasing the company offered a modellable detail: both of the past two years showed a very high Q4 revenue share; in 2025 the first three quarters swung widely, while in 2026 they were relatively stable at roughly RMB 1.8B each, with a heavier fourth quarter. On the nine-month numbers, Q4 has to come in well above RMB 1.8B to land inside the 19%–22% range — which makes Q4 delivery execution a capacity stress test in its own right.

"Ticket" is the word to remember

Asked how the supply-demand relationship will evolve as domestic peers pile into ADC and oligonucleotides, the company gave the most substantive answer of the call: peptides, DC and oligonucleotides are technically harder and process-wise more complex than small molecules, and demand more of the quality system and technical service capability; taking large-pharma orders requires more than hardware capacity, it requires accumulated soft capability; the company has secured the "ticket" in these fields, and globally those tickets are scarce, so supply will continue to lag demand growth for several years.

The word "ticket" captures the 2026 dividing line precisely: the shift from who owns reactors to who has been qualified by a major customer. Qualification is not one audit but a chain of events — quality agreements, PAI inspections, commercial batch release history, change-control records. It cannot be shortened with capex, nor bought with a low price. It also explains why the industry simultaneously contains companies with capacity but no qualification and companies with qualification but no capacity, and why the two should not trade on the same multiple.

Placing the four lines on a timeline

Q4 2026 is the delivery peak. Quarterly revenue must come in well above the roughly RMB 1.8B run rate of the first three quarters, while all four lines are simultaneously expanding or ramping — delivery and construction in parallel.

2027 is the first year capacity lands. Existing peptide capacity runs full, new peptide capacity comes online; antibodies and fusion proteins enter their first commercial year; new payload-linker capacity ramps; drug product takes more late-stage work in cartridges, prefilled syringes and blow-fill-seal. The company also expects 2027 growth to exceed 2026 — a guidance that only holds if capacity arrives on schedule.

From 2028 onward, the antibody gap persists. That implies expansion demand continues for another two years and capex does not peak in 2027.

Put that timeline beside peers and the whole industry is doing the same thing in the same window. Jiuzhou Pharmaceutical: 2026 fixed-asset investment capped at RMB 1B, Suzhou small-molecule commercial line commissioning in H2 2027, a Taizhou ADC line built in 2027, peptide growth constrained by capacity and oligonucleotides still in platform validation. WuXi AppTec: solid-phase peptide capacity moving from 100,000 to 130,000 litres, plus a RMB 10.1B, 800-tonne API programme in Changzhou. Samsung Biologics: PolyPeptide tender accepted at 87.92%, with Bio Campus II plants 6 to 8 at 180,000 litres each taking total capacity to 1.385 million litres.

Editorial note: three pricing implications of tight capacity

For CDMOs, tightness restores pricing power. Asymchem speaks of reasonable cost plus reasonable margin; Apeloa says order prices have stayed stable — two companies at different scales and in different niches pointing at the same fact: there is no price war at this tier in 2026. But tightness also means delivery risk, and the heavy fourth quarter is itself a stress test whose result will show up in 2027 renewals.

For customers, dual sourcing, reserved capacity and earlier order locking will become standard. Section 232 then adds an origin variable on top: the same "very tight" payload-linker capacity carries a different tariff identity depending on whether it sits in the US, the EU or China. ADCs are inside the exemption list, but commercial imports beyond clinical and R&D use still need to be checked category by category and jurisdiction by jurisdiction. Site selection has stopped being purely a cost decision.

For investors, the dispersion in utilisation will exceed the dispersion in revenue growth. If the premise holds — scarce tickets, supply lagging demand — then what is scarce is not litres but qualified litres. The next metric for a CDMO may not be construction in progress but the number of PAI-cleared lines and the commercial batch release record. Neither can be replicated inside a quarter.