Published in Annals of Oncology: Disitamab Vedotin Combined with PD-1 Inhibitor is a Promising Treatment for Locally Advanced or Metastatic Urothelial Carcinoma

Rhea-AI Summary

RemeGen's phase 1b/2 clinical trial results for Disitamab Vedotin (DV) combined with Toripalimab in treating locally advanced or metastatic urothelial carcinoma (la/mUC) were published in Annals of Oncology. The nearly three-year follow-up data showed impressive results with a 73.2% objective response rate (ORR) and 33.1 months median overall survival (OS).

The study enrolled 41 patients between August 2020 and December 2021. Key findings include: 9.8% complete response rate, 63.4% partial response rate, 90.2% disease control rate (DCR), 9.3 months median progression-free survival (PFS), and 8.6 months median duration of response (DOR). The 36-month OS rate was 49.2%.

Notably, patients with HER2 expression (IHC 1+/2+/3+) showed better outcomes with 76.3% ORR compared to 33.3% in HER2 IHC 0 patients. The therapy demonstrated efficacy across various subgroups, including chemotherapy-naïve patients (76.0% ORR) and those who progressed on platinum-based chemotherapy (68.8% ORR).

Positive

• High objective response rate of 73.2% in clinical trial
• Strong median overall survival of 33.1 months
• 90.2% disease control rate achieved
• Effective across multiple patient subgroups, including chemotherapy-naïve (76.0% ORR) and post-platinum therapy (68.8% ORR)
• Better outcomes in HER2-expressing patients (76.3% ORR vs 33.3% in non-expressing)

Negative

• None.

YANTAI, China, Jan. 8, 2025 /PRNewswire/ -- On Janurary 7th, 2025, Annals of Oncology (IF: 56.7), a top oncology journal globally, published remarkable long-term follow-up results of a phase 1b/2 clinical trial on Disitamab Vedotin (DV) (developed by Remegen Co., Ltd) combined with Toripalimab in treating locally advanced or metastatic urothelial carcinoma (la/mUC) (NCT04264936, study ID: RC48-C014). This trial was supervised by Professor Jun Guo and Professor Xi'nan Sheng's teams from Peking University Cancer Hospital.

It is the first time that long-term follow-up data has been released for a HER2-targeted antibody-drug conjugate (ADC) and PD-1 inhibitor combination therapy in treating la/mUC, marking it a significant milestone. The nearly-three-year follow-up data revealed an objective response rate (ORR) of 73.2% and median overall survival (OS) of 33.1 months, superior to data published from any other prospective clinical studies on ADC plus PD-1 combination therapies for la/mUC.

New Treatment Options for Patients with La/mUC

UC is the sixth most common cancer worldwide. GLOBOCAN 2022 estimated the year 2021 saw 614,298 new cases and 220,596 deaths of UC. In recent years, the prognosis for patients with la/mUC has significantly improved with new drugs and combination therapies approved, among which ADCs demonstrated outstanding potential.

As a HER2-targeted ADC, DV has been approved in China for patients with HER2-overexpressing (defined as immunohistochemistry [IHC] test results of 2+ or 3+) la/mUC previously treated with platinum-containing chemotherapy. The approval is based on the pooled results of two studies (NCT03507166 and NCT03809013, study IDs: RC48-C005 and RC48-C009) where the ORR registered 50.5% and the median duration of response (DOR) registered 7.3 months.

Multiple clinical studies on la/mUCin recent years have confirmed the synergistic antitumor effects of ADC combined with immunotherapy. NCT04264936 offered stronger evidence as its long-term follow-up results published in the Annals of Oncology demonstrated the high response rate, significant survival benefits, and manageable safety profile of the DV and Toripalimab combination therapy.

DV Combined with Toripalimab: High Response Rate and Prolonged Survival

NCT04264936 is an open-label, multicenter, investigator-initiated phase 1b/2 clinical trial investigating the safety and efficacy of DV in combination with Toripalimab for the treatment of patients with HER2-expressing la/mUC. The dose-escalation study (phase 1b) assessed two dose levels of DV (1.5 and 2.0 mg/kg) combined with Toripalimab (3.0 mg/kg) to determine the recommended phase 2 dose which was then evaluated in the dose-expansion stage (phase 2).

From August 2020 to December 2021, 41 patients were enrolled with a median age of 66 years. 53.7% of the participants were male, 70.7% had an ECOG performance status score of 1, 17 (41.5%) had lung metastasis, and 10 (24.4%) had liver metastasis.

As of March 1, 2024, among all participants, the ORR was 73.2% with 4 (9.8%) achieving complete response and 26 (63.4%) achieving partial response, the DCR was 90.2%, the median progression-free survival (PFS) was 9.3 months, the median DOR was 8.6 months, the median OS was 33.1 months and the 36-month OS rate was 49.2%.

Subgroup analysis revealed ORR benefits across all subgroups regardless of the number of prior lines of systemic treatments, HER2 expression (IHC 1+/2+/3+), and PD-L1 expression status. The ORRs for chemotherapy-naïve patients and those who progressed on platinum-based chemotherapy were 76.0% (19/25) and 68.8% (11/16), respectively. The ORRs for patients with HER2 IHC 3+, 2+, 1+, or 0 were 80.0%, 84.2%, 64.3%, and 33.3%, respectively. Compared with the three HER2 IHC 0 participants (one of whom achieved partial response), those with HER2 expression (IHC 1+/2+/3+) had a higher ORR (76.3% vs 33.3%) and longer PFS (median PFS: 9.3 vs 1.7 months).

In summary, the DV and Toripalimab combination therapy has preliminarily demonstrated promising efficacy and manageable safety profile among patients with la/mUC, wherein those with HER2 expression (IHC 1+/2+/3+) achieved high response rates and long-term survival benefits. These findings support the further exploration and validation of the benefits of DV combined with PD-1 inhibitors in treating la/mUC.

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SOURCE RemeGen Co., Ltd

FAQ

What are the key efficacy results of RemeGen's DV and Toripalimab combination therapy for la/mUC?

The combination therapy showed a 73.2% objective response rate, 33.1 months median overall survival, 9.3 months median progression-free survival, and 8.6 months median duration of response.

How does HER2 expression affect the treatment outcomes in the REGMY clinical trial?

Patients with HER2 expression (IHC 1+/2+/3+) showed better outcomes with 76.3% ORR and 9.3 months median PFS, compared to 33.3% ORR and 1.7 months PFS in HER2 IHC 0 patients.

What is the response rate for chemotherapy-naïve patients versus those who had prior platinum therapy?

Chemotherapy-naïve patients showed a 76.0% ORR, while patients who progressed on platinum-based chemotherapy achieved a 68.8% ORR.

What is the 36-month overall survival rate for patients treated with DV and Toripalimab?

The 36-month overall survival rate was 49.2% for patients treated with the combination therapy.