Recently, the 2026 European Society of Medical Oncology (ESMO) was held in Madrid, Spain. It received widespread attention from the international academic community, and investors in the global secondary market are also actively exploring investment opportunities.
The Zhitong Finance App observed that on October 23, Zaiding Pharmaceutical's stock price surged, with the highest intraday share price increase of 11.12% on the same day; the stock trading volume reached 3.6915 million shares on the same day, a new high in the past 2 months, with a corresponding turnover of 86.931 million US dollars, reflecting a significant increase in trading enthusiasm in the market.
The reason for the positive response from the secondary market is that the company announced the first data from a global phase Ib clinical study evaluating zocilurtatug pelitecan (Zoci, formerly ZL-1310) combined with atilizumab (with or without carboplatin) for first-line treatment of extensive small cell lung cancer (ES-SCLC) at the ESMO conference on the same day.
Its impressive data results have been widely recognized by academia and capital markets around the world, and investors are looking forward to the future global commercialization prospects of this product. Investment bank Cantor released a research report that the data released by Zaiding DLL3 ADC zoci in first-line widespread small-cell lung cancer has reached the “Home Run (home run)” level. Thoracic oncologists at New York University Grossman School of Medicine who also participated in the discussion are optimistic that zoci will replace first-line chemotherapy, which has the potential to change the first-line treatment pattern and gradually grow into a cornerstone therapy (Backbone Therapy) for small cell lung cancer treatment.
Remarkable clinical data, one more step towards “de-chemotherapy”
As a DLL3 targeted ADC drug developed in-house by Zaiding Pharmaceutical and independently promoting global clinical trials, and is also one of the fastest progressing DLL3 ADCs in the world, Zoci has been highly exposed at international authoritative conferences since entering phase I clinical trials, and has shown broad treatment prospects in the field of small cell lung cancer and neuroendocrine tumors.
In less than two years, Zaiding advanced zoci from the first human trial (FIH) application for a new drug clinical trial (IND) to the global phase III registration study stage, and obtained orphan drug qualification and fast track qualification from the US FDA, orphan drug qualification by the European EMA, and breakthrough therapy qualification by the China National Drug Administration, fully demonstrating that it has received unanimous recognition from the global industry and authoritative regulators, and also reflects the Zaiding global team's excellent collaborative ability and clinical development efficiency.
In this context, Zaiding Pharmaceutical and Zoci's latest research results on first-line treatment of small cell lung cancer appeared at this year's eSMO annual conference, which undoubtedly became the focus of the industry's attention.
According to the Zhitong Finance App, the data released by Zaiding this time comes from a global Phase Ib study to evaluate the first-line treatment of extensive small cell lung cancer (ES-SCLC) with Zoci and atilizumab. There are two options: a “double drug plan” (Zoci+ atirizumab) without chemotherapy, and a “three-drug plan” with carboplatin added on this basis.
The dual-drug solution is the core of this data. At the recommended phase III study dose (RP3D) of 1.6 mg/kg (n=33), the confirmed objective response rate (ORR) of the dual-drug regimen reached 81.8%, and the 6-month progression-free survival rate was 81.9%.
Relief not only came quickly, but also lasted a long time. Of the 15 patients who were followed for at least 6 months, median progression-free survival (mPFS) and median duration of remission (MdOR) had not been achieved at a median follow-up of 10 months. Of these, 10 patients (66.7%) still had no disease progression.
Safety is also a highlight of the dual-drug solution. At a dose of 1.6 mg/kg, most of the adverse events associated with Zoci were grade 1 or 2; the incidence of grade 3 or higher adverse events (TRAE) associated with Zoci was only 9.1%, there were no treatment-related discontinuation or treatment-related deaths, and only 1 case of interstitial lung disease (ILD) /noninfectious pneumonia was grade 1.
As a control, the three-drug regimen (n=13, combined with multiple dose levels) confirmed ORR of 92.3%, MPFs of 8.4 months, and MDor of 7.7 months. However, toxicity increased markedly after adding carboplatin: the incidence of adverse events (TEAE) during grade 3 or higher treatment increased from 21.2% to 76.9% in the dual-drug regimen, mainly hematologic toxicity.
Simply put, the dual-drug regimen without chemotherapy has achieved a better balance between efficacy, durability, and safety; adding platinum chemotherapy in exchange for a higher remission rate, but it also poses a significantly heavier burden of hematologic toxicity. This is also the reason why the dual-drug solution became the focus of subsequent development.
In fact, the current standard treatment plan for first-line small cell lung cancer is immune checkpoint inhibitors combined with chemotherapy. The remission rate is 60-70%, the median progression-free survival period is about 5 months, and it is accompanied by about 60% of adverse events related to grade 3 and above treatment.
Compared with this (indirect cross-trial comparison, non-head-to-head), the data performance of the Zoci combined with atilizumab without chemotherapy at all conveyed a key signal: the chemotherapeutic plan with Zoci as the cornerstone is expected to bring better safety and longer lasting disease control while not inferior in efficacy to platinum-containing chemotherapy, and push ES-SCLC first-line treatment to take another step towards “de-chemotherapy”.
This idea also extends to joint development. The Zhitong Finance App learned that this year, Zaiding Pharmaceutical and Amgen have reached a global clinical research collaboration to evaluate the combined use of ZOCI and ImdellTra® (taratumab, a DLL3/CD3 bispecific TCE) for broad-stage small cell lung cancer; and reached a clinical research collaboration with Boehringer Ingelheim to evaluate the joint use of Zoci and Tamig (a DLL3/CD3 bispecific TCE) for small cell lung cancer and other neuroendocrine cancers.
Two multinational pharmaceutical companies with DLL3 TCE have successively chosen to use it in combination with Zoci. There is a mechanistic basis behind Zoci: Zoci directly kills tumor cells through ADC endocyte release payload, does not rely on T cells, and complements the killing pathway of T cell connectors. This also reflects from the side that ZOCI is leading the development in the DLL3 ADC field and has the potential to be a cornerstone drug for combination therapy.
Leading global development and continuing to expand clinical value boundaries
From a market perspective, the current global lung cancer treatment market continues to expand and is expected to grow to 76.6 billion US dollars by 2030, of which small cell lung cancer accounts for about 15% of confirmed cases of lung cancer worldwide. Of the approximately 250,000 new cases of SCLC worldwide each year, about 2/3 are already widespread (ES-SCLC) when diagnosed, and they are still facing serious brain metastasis problems.
Although first-line immunotherapy combined chemotherapy has raised the median overall survival (OS) of ES-SCLC to 12-15 months, the long-term survival rate is still extremely low, with the 5-year survival rate hovering around 5% to 10%. It can be seen from this that there is still a lot of room for improvement in the treatment of small cell lung cancer, especially widespread small cell lung cancer, and clinical needs are very urgent.
In recent years, targets with high expression in SCLC tumor cells, such as DLL3, B7-H3, and SEZ6, have been discovered one after another, and have become an important direction for ADC development, and have also spawned a number of promising ADC drug candidates. Among them, DLL3 is highly expressed in SCLC and low in normal tissues, and is considered one of the targets with strong specificity. Zoci is one of the ADCs with the world's leading development schedule for this target.
Judging from the development progress, Zoci took less than two years from the first human trial IND to the global Phase III study. Both second-tier and first-tier research have entered or are about to enter global registration research, and the R&D and registration progress is in the first tier of global SCLC competition.
According to the Zhitong Finance App, Zaiding Pharmaceutical plans to submit the first marketing application for Zoci to the US FDA in 2027. If all goes well, ZOCI is expected to become the world's first approved DLL3 ADC.
epilogue
Data released at the ESMO annual conference showed that Zoci's chemotherapy-free regimen combined with atilizumab had a high remission rate, positive long-lasting signals, and outstanding safety, providing strong early evidence that it has entered the ES-SCLC frontline and promoted “de-chemotherapy.”
Whether it can become a first-line “cornerstone therapy” for small cell lung cancer ultimately depends on phase III overall survival data to answer. But ESMO data this time at least shows that replacing first-line chemotherapy with a safer ADC is no longer just an idea. From second-line to first-line, from single drug to combined use, Zoci's development path is gradually being clarified.