Therapeutic Peptide Vaccine for Fibrolamellar HCC – Phase 1 Trial
Here’s a breakdown of the key information from the provided text,focusing on patient P14 and the implications for their treatment:
* Initial Response & Recurrence: Patient P14 initially responded to nivolumab (an anti-PD-1 therapy) but experienced lung recurrence 2 years later.
* Resistance Mechanism: Tumor profiling after recurrence showed expression of DNAJ-PKAc and intact HLA class II expression. This suggests the tumor didn’t lose its ability to be seen by the immune system (HLA class II) and continued to express the target antigen (DNAJ-PKAc), indicating a mechanism other than antigen loss was driving resistance. The text suggests oligoprogression may have contributed.
* CD4 T Cell Response: cytof analysis revealed a CD4 T cell-driven response against DNAJ-PKAc. This is meaningful because CD4 T cells play a crucial role in coordinating the immune response.
* Rechallenge with combination Therapy: As nivolumab alone failed, the patient was retreated with a combination of nivolumab and ipilimumab.Ipilimumab is an anti-CTLA-4 therapy known to boost CD4 T cell activity (references 12 & 13).
* Successful Outcome: The combination therapy led to a complete response (as shown in Fig. 4f).
In essence, this case study suggests that resistance to anti-PD-1 therapy can develop without losing the target antigen. Boosting the CD4 T cell response with an anti-CTLA-4 agent (ipilimumab) was able to overcome this resistance and restore a complete response.