1375P SHR-1701, a novel bifunctional anti-PD-L1/TGF-βRII agent, for pretreated recurrent/refractory (r/r) gastric cancer (GC): Data from a first-in-human phase I study

Development of pharmacological immunoregulatory anti-cancer therapeutics: current mechanistic studies and clinical opportunities

Immunotherapy represented by anti-PD-(L)1 and anti-CTLA-4 inhibitors has revolutionized cancer treatment, but challenges related to resistance and toxicity still remain. Due to the advancement of immuno-oncology, an increasing number of novel immunoregulatory targets and mechanisms are being revealed, with relevant therapies promising to improve clinical immunotherapy in the foreseeable future. Therefore, comprehending the larger picture is important. In this review, we analyze and summarize the current landscape of preclinical and translational mechanistic research, drug development, and clinical trials that brought about next-generation pharmacological immunoregulatory anti-cancer agents and drug candidates beyond classical immune checkpoint inhibitors. Along with further clarification of cancer immunobiology and advances in antibody engineering, agents targeting additional inhibitory immune checkpoints, including LAG-3, TIM-3, TIGIT, CD47, and B7 family members are becoming an important part of cancer immunotherapy research and discovery, as are structurally and functionally optimized novel anti-PD-(L)1 and anti-CTLA-4 agents and agonists of co-stimulatory molecules of T cells. Exemplified by bispecific T cell engagers, newly emerging bi-specific and multi-specific antibodies targeting immunoregulatory molecules can provide considerable clinical benefits. Next-generation agents also include immune epigenetic drugs and cytokine-based therapeutics. Cell therapies, cancer vaccines, and oncolytic viruses are not covered in this review. This comprehensive review might aid in further development and the fastest possible clinical adoption of effective immuno-oncology modalities for the benefit of patients.

SHR-1701, a Bifunctional Fusion Protein Targeting PD-L1 and TGFβ, for Recurrent or Metastatic Cervical Cancer: A Clinical Expansion Cohort of a Phase I Study

PURPOSE

Patients with recurrent or metastatic cervical cancer have limited treatment options after platinum-containing treatment. We initiated a phase I study to assess SHR-1701, a novel bifunctional fusion protein composed of a mAb against programmed death ligand 1 (PD-L1) fused with the extracellular domain of TGFβ receptor II, in solid tumors (NCT03774979). Here, results from the cervical cancer cohort are presented.

PATIENTS AND METHODS

Patients with recurrent or metastatic cervical cancer who progressed during or after platinum-based therapy were enrolled to receive SHR-1701 at 30 mg/kg every 3 weeks. Primary endpoint was objective response rate (ORR) per RECIST v1.1.

RESULTS

In total, 32 patients were recruited. ORR was 15.6% [95% confidence interval (CI), 5.3-32.8], and disease control rate was 50.0% (95% CI, 31.9-68.1). Responses were still ongoing in 80.0% of the responders; 6-month duration of response rate was 80.0% (95% CI, 20.4-96.9). Median progression-free survival (PFS) was 2.7 months (95% CI, 1.4-4.1). Of note, as assessed by immune-modified RECIST, median PFS was 4.1 months (95% CI, 1.6-4.3). Overall survival rate at 12 months was 54.6% (95% CI, 31.8-72.7). Treatment-related adverse events of grade 3 or 4 were reported in 11 (34.4%) patients. No treatment-related deaths occurred. No difference in ORR was found between patients with PD-L1 combined positive score ≥1 or <1; patients with high phosphorylated SMAD2 level in immune cells or tumor cells had numerically higher ORR.

CONCLUSIONS

SHR-1701 exhibits encouraging antitumor activity and controllable safety in patients with recurrent or metastatic cervical cancer after platinum-based regimens, and therefore might provide another treatment option for this population. See related commentary by Miller and Friedman, p. 5238.

Therapeutic targeting of VEGF and/or TGF-β to enhance anti-PD-(L)1 therapy: The evidence from clinical trials

Normalizing the tumor microenvironment (TME) is a potential strategy to improve the effectiveness of immunotherapy. Vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-β pathways play an important role in the development and function of the TME, contributing to the immunosuppressive status of TME. To inhibit VEGF and/or TGF-β pathways can restore TME from immunosuppressive to immune-supportive status and enhance sensitivity to immunotherapy such as programmed death protein-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) inhibitors. In this review, we described the existing preclinical and clinical evidence supporting the use of anti-VEGF and/or anti-TGF-β therapies to enhance cancer immunotherapy. Encouragingly, adopting anti-VEGF and/or anti-TGF-β therapies as a combination treatment with anti-PD-(L)1 therapy have been demonstrated as effective and tolerable in several solid tumors in clinical trials. Although several questions need to be solved, the clinical value of this combination strategy is worthy to be studied further.