Nasopharyngeal carcinoma (NPC), often referred to as the “Guangdong cancer,” is particularly prevalent in southern China. First-line treatment with gemcitabine plus platinum-based chemotherapy combined with a PD-1 inhibitor has become the standard of care. However, for patients with recurrent or metastatic (R/M) disease whose cancer progresses following immunotherapy and platinum-based chemotherapy, later-line treatment options remain limited. Treatment still relies primarily on single-agent chemotherapy, such as gemcitabine and docetaxel, with objective response rates (ORRs) of only 10%–30% and median progression-free survival (PFS) of approximately 3–4 months. An effective standard treatment for this setting has long been lacking.Antibody-drug conjugates (ADCs) have generated considerable expectations. Acting like “biological missiles,” they deliver highly potent payloads directly to tumor cells and can also kill neighboring heterogeneous tumor cells through the bystander effect. B7-H3 (CD276) is an attractive target in this regard: it is expressed at very low levels in normal tissues but is highly expressed in NPC and various other solid tumors. However, previous clinical studies of B7-H3-targeting monoclonal and bispecific antibodies have failed to achieve breakthroughs, leading this target to be considered difficult to drug.
At the 2026 European Society for Medical Oncology (ESMO) Congress, the TAISHAN-301 study, led by Professor Li Zhang and Professor Shaodong Hong’s team at Sun Yat-sen University Cancer Center, was presented as a late-breaking abstract (LBA) in the Proffered Paper session. The results demonstrated that tam-peli (YL201), a domestically developed B7-H3 ADC, increased the blinded independent central review (BICR)-assessed confirmed ORR in heavily pretreated patients with R/M NPC from 25.8% with chemotherapy to 50.8% (OR 2.9, one-sided P<0.0001), nearly doubling the response rate. This makes it the first B7-H3 ADC worldwide to report positive phase III results in later-line NPC treatment. Following the congress, Oncology Frontier interviewed the presenting investigator, Professor Shaodong Hong, who discussed the study findings, the mechanisms underlying its activity in patients previously treated with immunotherapy, and its differentiated positioning compared with the approved EGFR×HER3 ADC iza-bren.
Expert Interview
Oncology Frontier:
Could you introduce the main findings of the TAISHAN-301 study?
Professor Shaodong Hong: At this year’s ESMO Congress, we presented the results of the first global phase III clinical study of a B7-H3 ADC in later-line NPC treatment in a Proffered Paper session. The drug is tam-peli (Tam-Peli), with the development code YL201. It is a humanized monoclonal antibody-drug conjugate targeting B7-H3.
In our earlier phase I clinical study, we identified two patient populations with particularly promising responses: one with small cell lung cancer and the other with NPC. NPC is especially distinctive because it is highly prevalent in China and is commonly referred to as the “Guangdong cancer.” It is particularly common in southern China and Southeast Asia.
Regarding the treatment landscape, first-line NPC treatment consists of platinum-based chemotherapy combined with immunotherapy. In the second-line setting, single-agent chemotherapy is currently the main preferred option. After patients have received platinum-based chemotherapy and second-line chemotherapy, however, their treatment choices become extremely limited. They generally have to rely on single-agent chemotherapy such as gemcitabine, docetaxel, capecitabine, or vinorelbine. Response rates are generally around 10%–30%, and PFS is only approximately three to four months. This represents a substantial unmet medical need.
Based on our earlier exploration of efficacy and safety, we conducted this phase III study comparing YL201 with investigator’s choice of single-agent chemotherapy. The co-primary endpoints were BICR-assessed confirmed ORR and OS. A total of 431 patients were randomized (215 to the experimental group and 216 to the control group). The data presented at this congress came from a prespecified interim analysis involving the first 254 patients randomized (126 in the experimental group and 128 in the control group). At the data cutoff, the median follow-up was approximately five months.
The results were clear: the confirmed ORR was 25.8% in the control group, compared with 50.8% in the experimental group receiving this B7-H3 ADC, approximately twice the response rate (OR 2.9, one-sided P<0.0001). This means that B7-H3 ADC treatment achieved both clinically meaningful and statistically significant improvements in patients with NPC receiving third-line or later treatment.
It is important to note that this is still an interim analysis. The OS endpoint has not yet been reached, and the PFS data are not yet mature. Nevertheless, based on the stronger ORR, higher disease control rate (DCR; 93.7% vs. 75.8%), and longer duration of response (7.9 months vs. 6.4 months) observed so far, we believe these findings support B7-H3 ADC as a potential new treatment option for patients with NPC in the third-line or later setting. The National Medical Products Administration (NMPA) will also evaluate whether the drug may qualify for conditional marketing approval based on ORR as a primary endpoint.
Oncology Frontier:
The study enrolled patients with heavily pretreated R/M NPC. Had the vast majority already received PD-1 inhibitor combined with chemotherapy? What mechanisms explain the continued efficacy of B7-H3 ADCs in patients previously treated with immunotherapy? Could B7-H3 expression levels or previous responses to immunotherapy affect the treatment benefit?
Professor Shaodong Hong: This point is very clear: prior immunotherapy and platinum-based chemotherapy were mandatory prerequisites for enrollment. In other words, 100% of patients had received immunotherapy and platinum-based chemotherapy, and all had experienced treatment failure after at least second-line chemotherapy. This was truly a heavily pretreated population.
Why does the drug remain effective in this population? We need to start with B7-H3. B7-H3 is a member of the B7 immune superfamily and has both immunoregulatory and tumor-promoting functions. NPC in endemic regions is associated with viral infection and is generally considered a “hot tumor.” B7-H3 is broadly and highly expressed in this disease, which helps explain why patients can benefit from first-line immunotherapy combined with chemotherapy. However, once patients develop resistance to both immunotherapy and platinum-based chemotherapy, there are few clearly defined, actionable targets available.
This is precisely where ADCs have an advantage: they can use a target that is highly expressed on tumor cells and capable of internalization to achieve targeted tumor killing while also modulating the tumor microenvironment.
Regarding the question of whether B7-H3 expression levels predict treatment efficacy, we have not observed a significant association between expression and response so far. A comprehensive analysis of the relationship between expression and efficacy in this phase III study is still ongoing, but our earlier phase I data suggested that the association was not particularly strong.
The key reason is the bystander effect of ADCs. After the ADC is internalized following binding to B7-H3-positive cancer cells, the released payload can cross cell membranes and diffuse into neighboring tumor cells that do not express B7-H3, killing them as well.
This has considerable clinical value. It suggests that, in the future, we may not need to rely on testing B7-H3 expression levels to identify patients who could benefit from this drug, potentially allowing a broader eligible patient population.
Oncology Frontier:
In later-line NPC treatment, GP plus a PD-1 inhibitor has become the first-line standard, while the EGFR×HER3 bispecific ADC iza-bren has also demonstrated an ORR advantage in the later-line setting. As a B7-H3 ADC, what are the differentiated advantages of Tam-Peli, and how might it change the later-line treatment landscape for R/M NPC?
Professor Shaodong Hong: We know that the first ADC approved for later-line NPC treatment was actually the EGFR/HER3 ADC, iza-bren. It received conditional approval in June 2026 for R/M NPC following progression on a PD-(L)1 inhibitor and at least two lines of chemotherapy. This drug was also developed and approved through the efforts of Professor Li Zhang, the principal investigator of the present study.
Iza-bren is an EGFR×HER3 bispecific ADC with a drug-to-antibody ratio (DAR) of 8. Its characteristic features include bone marrow toxicity and deep tumor responses. In a similarly designed patient population, it also achieved an ORR approximately twice that of conventional chemotherapy (PANKU-NPC01: 54.6% vs. 27.0%). Significant PFS improvement has also been reported, with median PFS of 8.38 months versus 4.34 months.
Compared with iza-bren, the B7-H3 ADC Tam-Peli presented at this congress has two main distinguishing characteristics.
First, its dosing schedule is more convenient. It is administered once every three weeks (Q3W), meaning patients do not need to make two hospital visits within a three-week period, as is required with some ADC regimens. This can help improve patient management and treatment adherence.
Second, its bone marrow toxicity burden appears relatively lower. In this study, the incidence of grade ≥3 treatment-related adverse events was 49.3% in the Tam-Peli group, comparable to 51.7% in the chemotherapy group. The incidence of grade ≥3 neutropenia was 27.0%, and no cases of interstitial lung disease were observed in either group. By comparison, iza-bren has demonstrated more prominent myelosuppression. It is important to emphasize that this comparison is based on the separately reported data from two different studies, not a head-to-head trial, and should therefore be interpreted with caution. Nevertheless, this profile may make Tam-Peli easier to manage clinically, both in terms of primary and secondary prevention of bone marrow toxicity and the management of complications associated with myelosuppression.
Of course, an important distinction must be emphasized: Tam-Peli and iza-bren have each been independently compared with standard single-agent chemotherapy. There has been no direct comparison between the two drugs, and their relative efficacy and safety cannot currently be assessed against one another.
My personal view is that both drugs may become available treatment options for similar patient populations in the future. Clinicians will need to make individualized treatment decisions based on the different toxicity profiles and treatment management requirements of the two drugs, rather than simply ranking one as “better” than the other.
Summary
From a B7-H3 target once considered difficult to drug to the achievement of the first positive global phase III results, TAISHAN-301 has opened a new door for patients with R/M NPC who have exhausted immunotherapy and chemotherapy options and have very few remaining treatments available.
The combination of a nearly doubled ORR, the potential to avoid dependence on B7-H3 expression testing for patient selection, a convenient dosing schedule, and a relatively manageable bone marrow toxicity profile makes this a promising and potentially accessible later-line treatment option.
Of course, mature OS and PFS data will require further follow-up. Whether this drug will ultimately reshape the later-line treatment landscape as anticipated remains a question that only time and continued clinical evidence can answer.
