YL201: the world’s only Phase 3 in nasopharyngeal carcinoma

MediLink Therapeutics was founded in 2020, headquartered in Suzhou, with R&D bases in Shanghai and Boston. The TMALIN® platform (Tumor Microenvironment Activable LINker) built by founder and CEO Dr. Xue Tongtong uses a dual-cleavage mechanism — the first cleavage in the extracellular tumor microenvironment and the second in the lysosome — paired with a novel topoisomerase inhibitor-class payload (same class as Daiichi Sankyo’s DXd, with a differentiated chemical structure), emphasizing DAR homogeneity and therapeutic window.

As of May 2026, MediLink has three clinical-stage ADCs:

• YL201 · B7-H3 ADC, China retained + Roche ex-China (2026-01)
• YL202 / BNT326 · HER3 ADC, exclusive global license to BioNTech (2023-10)
• YL211 · c-Met ADC, exclusive global license to Roche (2024-01)

The three BD deals total more than US$3 billion cumulatively (including milestones). Add the TMALIN platform multi-target option deal BioNTech signed in May 2024 (US$25M upfront / up to US$1.8B), and MediLink has in effect become one of the Chinese ADC platform companies most favored by MNCs during 2023–2026. Seen in this context, YL201 is MediLink’s first, and so far only, asset for which it retains China rights and runs the China NDA itself.

YL201’s key supporting data were published in Nature Medicine in June 2025 (Ma Y et al., 31:1949-1957), with a Phase 1/1b total N=312 spanning multiple B7-H3-high tumor types including SCLC, NPC, NEC, NSCLC, endometrial cancer, sarcoma, CRPC and ESCC.

On safety, trilineage hematologic suppression was the dominant event across N=312 — decreased white blood cells 66.3% (≥G3 29.5%), anemia 64.7% (≥G3 25.0%), decreased neutrophils 61.5% (≥G3 31.7%). Notably, overall ILD (interstitial lung disease) was only 1.3%, significantly below the 3–7% range for DXd-platform peers. This is crucial for future NSCLC expansion cohorts — Chinese patients have smoking histories and smog-affected lung baselines, and ILD has become one of the safety signals physicians are most sensitive to in the PD-1 + chemotherapy era; a low baseline of 1.3% leaves room for YL201 in combinations in NSCLC 1L/2L.

YL201’s two current registrational studies:

The strategic implications of the two indications are completely different.

SCLC is the engine of ex-China global value. FDA Breakthrough Therapy Designation has landed, and once Roche upgrades to a global MRCT after taking over ex-China, SCLC is the indication most likely to enter an accelerated review channel first. But SCLC is also YL201’s most crowded race: Hansoh’s HS-20093 is already running the ARTEMIS-008 Phase 3 (with GSK taking it global), expected primary completion September 2026; Daiichi Sankyo/Merck’s ifinatamab deruxtecan (I-DXd) IDeate-Lung01 also received FDA BTD in August 2025; plus Amgen’s tarlatamab (a DLL3 BiTE, IMDELLTRA) received full FDA approval in SCLC 2L in November 2025 — meaning the value ceiling for YL201 in SCLC 2L is squeezed by contemporaneous assets, and differentiation must come from effect size and safety (especially low ILD).

NPC is the cleanest moat for MediLink’s China rights. Globally, YL201 is the only B7-H3 ADC in a registrational NPC study; more than 60% of global nasopharyngeal carcinoma patients are concentrated in South China and Southeast Asia, the EBV-positive proportion in South China is >95%, and B7-H3 expression in NPC is 70–85%; the current SoC has almost nothing standard after failure of PD-1 + chemotherapy — a baseline single-agent chemotherapy ORR of 10–20% leaves significant differentiation room for YL201’s 48.6% response. Once the NPC Phase 3 reads out positive, MediLink will in effect hold, exclusively in China, an NDA for a globally new mechanism.

In 2025–2026, B7-H3 suddenly became one of the most crowded new hotspots for global ADCs. The reason: B7-H3 is highly expressed in multiple tumor types including SCLC, NPC, CRPC, neuroblastoma, sarcoma and endometrial cancer, with limited expression in normal tissue and no clear evidence of resistance mechanisms — a nearly perfect ADC target of “standardized antigen + multiple tumor types + large space”. There are currently four main players:

The four players differentiate along three dimensions:

Effect size: YL201’s ORR of 67.7% in SCLC at 2.0 mg/kg is the highest in currently public data (albeit with a small sample and short follow-up); HS-20093’s 71.4% at 10 mg/kg is close but at a higher dose, with toxicity needing longer follow-up to validate; I-DXd’s 48.2% already comes with a more mature mOS of 10.3 months, the “landed” benchmark for SCLC ADCs.

Competitive window: I-DXd’s IDeate-Lung01 already has a full Phase 2 readout + FDA BTD; HS-20093’s ARTEMIS-008 Phase 3 has primary completion in 2026-09, a year earlier than YL201’s SCLC Phase 3 (2027-12). This means YL201’s ex-China SCLC launch will come after 2028 at the earliest, by which time I-DXd and HS-20093 may already have divided most of the SCLC 2L market.

Tumor-type exclusivity: this is YL201’s real moat — the NPC Phase 3 is the only one in the world; none of the other three has a registrational NPC study. In LELC, a globally rare EBV-related tumor type, YL201 also holds the first response data exclusively at Phase 1. Together, these two tumor types form a combination unique to MediLink’s China rights: “globally new mechanism + regionally scarce patient pool”.

So YL201’s global value story can in fact be split into two lines: in SCLC, holding ground in a highly competitive race on effect size and safety (especially low ILD), and in NPC + LELC, a differentiated narrative in which MediLink alone takes a B7-H3 ADC to a global first position. Roche’s choice to take ex-China rights 13 months after both the NPC and SCLC Phase 3 trials started clearly shows it valued this combination, not just SCLC alone.

Of MediLink’s four out-licensing deals, the first three were exclusive global licenses; only YL201 keeps China and gives ex-China to Roche. This difference is not accidental — it shows how a biotech, in the frenzy of ADCs going global, finely separates the two actions of “realizing value” and “accumulating value”.

The cumulative upfronts plus near-term milestones across the four deals exceed US$700 million; add the US$70 million Series B, and MediLink, without listing, has stretched its runway through the “R&D cash-burn phase” to more than 5 years. That is why YL201 can “retain China rights”: MediLink doesn’t need China sales of YL201 to keep itself alive, and can deploy cash and time to build a China commercial team gradually.

Even more worth unpacking is the granularity of the rights split. Roche took all rights “worldwide except mainland China, Hong Kong and Macau” — note that Taiwan goes to Roche, meaning MediLink’s China sales network covers only the mainland, Hong Kong and Macau, and Roche takes on the Taiwan NDA. The split has no co-promotion and no co-development; the structure is clean:

• MediLink independent in China: the full set of China IND/Phase 3/NDA/NMPA/commercialization, 100% autonomous
• Roche independent ex-China: the full set of global MRCTs, FDA/EMA registration and ex-China commercialization
• Cash flow: US$570M upfront + subsequent development/regulatory/commercial milestones + ex-China tiered royalties
• No room for future BD (global rights fully allocated); the next BD window must come from new tumor-type combinations or add-on new indications

This structure has a hidden tension: FDA BTD was obtained before Roche took over, and Roche will use it to push the global launch pace to the maximum, while CDE BTD has not yet been publicly listed. If SCLC launches globally before China, the China market narrative (especially with KOLs and payers) needs proactive management — “approved in the US first, China later” must not become a reverse negative signal for domestic innovative drugs.

2023–2026 is the window for Chinese ADCs going global. Putting the MediLink–Roche YL201 deal into the sequence of contemporaneous Chinese ADC out-licensings helps to understand the true worth of the US$570 million upfront:

Several points in this chart are worth unpacking:

The pricing gap between retaining regional rights and exclusive global rights. Biokin’s BL-B01D1 was an exclusive global license with an US$800M upfront; MediLink’s YL201 is an exclusive ex-China license with a US$570M upfront. Adjusting back for “regional scope”, YL201’s unit price per square meter of global rights is in fact higher than BL-B01D1’s — reflecting MNCs’ high valuation of MediLink’s TMALIN platform + the multi-tumor potential of B7-H3.

Cumulative bets by the same MNC. After signing YL211 in 2024, Roche signed YL201 in 2026, returning to the same platform twice within two years. Such “cumulative bets by the same MNC” have only been achieved in the sequence of Chinese ADC out-licensings by a few companies: MediLink (Roche ×2), BeiGene (historical collaborations with Pfizer/Novartis) and Innovent (Lilly). The implicit meaning is: Roche has chosen TMALIN as a long-term platform entry point in its ADC strategy, and there may be more follow-on deals.

The ceiling implications of the US$570M figure. For an unlisted biotech with a US$70M Series B, a single US$570 million upfront means: (1) financially, it no longer needs to raise money for the YL201 project, and can shift its IPO valuation anchor from “cash needs” to “global narrative”; (2) on valuation, given MediLink’s current pipeline depth (three BD deals for YL202/YL211/YL201 + the TMALIN platform option + 5+ early pipelines), a reasonable Hong Kong IPO valuation range should be US$3–5 billion; (3) strategically, MediLink has in effect upgraded from a “NewCo-style selling pipelines” model to a hybrid model of “retain China + deep global collaboration”.

Nasopharyngeal carcinoma is the tumor type with the best story in YL201’s China rights. China has ~60,000 new cases and ~34,000 deaths a year, concentrated in Guangdong in South China (30.3 per 100,000 in men, 13.1 per 100,000 in women) and in Guangxi, Fujian, Hainan and elsewhere. The EBV+ proportion in South China is >95%, while EBV+ NPC is actually rare in Western populations — meaning NPC is an unusual combination of “a locally scarce tumor type unique to China + a globally exclusive Phase 3 asset”.

The eligibility criteria of YL201’s NCT06629597 are precisely “after failure of PD-(L)1 + ≥2L chemotherapy” — a typical 3L+ population with extremely unmet need; the improvement from single-agent chemotherapy’s 10–20% ORR to 48.6% could, in CDE’s eyes, constitute the clinical benefit basis for accelerated approval of a monotherapy (with reference to the accelerated pathway precedent of trastuzumab deruxtecan in HER2-low BC). There is no precedent anywhere in the world for a single-agent ADC after second line in NPC; once YL201 reads out positive, MediLink will in effect hold, exclusively in China, an NDA for a globally new mechanism — a narrative with enormous support for a Hong Kong IPO valuation.

On the leading PI network, Professor Ma Jun of Sun Yat-sen University Cancer Center (SYSUCC) is the globally recognized leader in NPC, which is why the Phase 3 chose Sun Yat-sen as its first site. But enrolling 400 patients at the Sun Yat-sen site alone would take far too long, and it must quickly expand to Guangdong Provincial People’s Hospital, Fudan University Shanghai Cancer Center, Fujian Cancer Hospital, Guangxi Medical University Cancer Hospital, West China Hospital and others.

The ADC process is far more complex than for a monoclonal antibody: antibody production + payload synthesis + conjugation + purification, any step of which can affect DAR homogeneity. The TMALIN platform’s dual-cleavage linker + Topo-I payload adds another layer of difficulty in payload containment and safe handling (the payload is highly potent, placing high demands on protection of production staff and contained facility design).

MediLink has not disclosed its own commercial GMP facility and is very likely highly dependent on external CDMOs — domestic capacity for commercial ADC manufacturing is concentrated in three companies: WuXi XDC, TOT Biopharm and Mabplex. Clinical batches during Phase 3 have most likely already been produced at CDMOs, but process performance qualification (PPQ) of commercial batches, release criteria for critical quality attributes (CQA) and stability data are must-check items for the China NDA, and core disclosures in a Hong Kong IPO prospectus.

A potential coupling issue: will Roche’s ex-China commercial supply use MediLink’s CDMO chain, or will Roche transfer the technology to its own global plants? This affects the COGS split, IP control and supply stability. Roche will certainly do tech transfer during Phase 3, and MediLink’s process transfer capability (already proven in the YL202 and YL211 deals) is a scarce capability.

This timetable has two hidden points of contention. First, the Hong Kong IPO will very likely happen before the Phase 3 data read out — the valuation anchor is the four-piece set of “completed BD + the world’s only NPC Phase 3 + FDA BTD + Roche endorsement”, not Phase 3 clinical results. This means the 2026 Hong Kong prospectus will be an exam of MediLink management’s narrative skills. Second, the HS-20093 ARTEMIS-008 readout in 2026-09 may change valuations — if HS-20093’s SCLC data are strong and it gets FDA BTD, YL201’s uniqueness in SCLC is immediately weakened; if HS-20093 fails or disappoints, YL201’s ex-China value in SCLC will be quickly re-rated upward.

The YL201 story is one of the most worthwhile cases to unpack among Chinese domestic ADC biotechs in 2026. It is neither simple BD-first (like many NewCo models) nor simple China-first (like traditional import substitution), but an “actuarial dual track” that discounts ex-China global rights to Roche for a US$570 million upfront with one hand, and retains China rights and builds its own commercialization capability with the other. The downside of this path has already been cushioned by Roche’s upfront; the upside depends on whether the two Phase 3 trials read out on schedule + whether the China commercial team can truly land in 2028–2029.

For an unlisted biotech, the granularity of this structure matters more than any single number. It tells the market: Chinese ADCs have moved past the stage of “sell it for cash” and are entering the next stop — “sell half, keep half, and grow your own commercial capability”.