Genetic factors
Additional research presented in that ESMO session offered insights into the genetic factors that may play key roles in either response or resistance to anti-PD-1 therapy in peripheral T cell lymphoma (PTCL), of which extranodal NK/T cell lymphoma is a subtype.
The findings are from a genetic analysis of a phase 2 trial that demonstrated benefits the PD-1 inhibitor geptanolimab in patients with PTCL who failed initial chemotherapy.
Specifically, geptanolimab treatment was associated with an objective response rate of 40.4%, a complete response rate of 14.6%, and partial response rate of 25.8%.
Of 44 patients who had been treated with geptanolimab and had next-generation sequencing genetic data available, PD-L1 expression was found to be significantly elevated among those who had a complete or partial response, whereas PD-L1 expression was lower among those who had disease progression, which is consistent with previous research suggesting that low PD-L1 expression is linked to poorer response to anti-PD-1 therapies.
Tumor mutation burden did not exhibit significant prognostic value. However, the authors noted that this may be confounded by variation across PTCL subtypes.
Among other key findings were that JAK3 and EZH2 mutations, which are among the top genes frequently mutated in PTCL and extranodal NK/T cell lymphoma, were consistently associated with low PD-L1 expression (P < .05) and shorter progression-free survival (HR 5.97; P = .027, JAK3, and HR 4.76; P = .027 EZH2).
“Notably, we found JAK3 mutations, which are vital and prevalent in PTCL, reduced PD-L1 levels in vivo and in vitro, which are of great clinical and biological sense,” said the study’s first author, Ning Lou, MD, of the Cancer Hospital Chinese Academy of Medical Sciences & Peking Union Medical College, in Beijing.
Commenting on the study, discussant Olivier Casasnovas, MD, PhD, of the department of hematology, University Hospital Francois Mitterrand in Dijon, France, said that the findings are especially notable in relation to extranodal NK/T cell lymphoma.
“The clinical relevance of anti PD1 is mainly observed in relapsing/recurrent extranodal NK/T cell lymphoma, and much less in other T-cell lymphoma subtypes,” he told this news organization.
“So identifying molecular events associated with the chance of response to a PD1 blocker in relapsing extranodal NK/T cell lymphoma is important as PD1-blockers are recommended to treat [those] patients,” Dr. Casasnovas added.
Furthermore, “the interest of next-generation sequencing to identify JAK3 mutations associated with low level of PDL1 expression and weak response to anti PD1 blockers is important as JAK3 mutated tumors are potentially targetable by JAK inhibitors such as tofacitinib,” he said.
“Obviously this assumption has to be tested in clinical trials but it’s an interesting lead.”
The research on toripalimab additionally shows that “the combination of radiotherapy and PD1 blockers provides a high response rate in patients who are nonresponders to asparaginase-based chemotherapy on the basis of PET evaluation and could be a new option for optimizing the first line treatment of extranodal NK/T cell lymphoma patients,” Dr. Casasnovas added.
The authors and Dr. Casasnovas had no disclosures to report.