The GEM-P chemotherapy regimen composed of gemcitabine, Platinol (cisplatin), and the corticosteroid methylprednisolone failed to improve response rates of peripheral T-cell lymphoma patients who have not received prior treatment, according to Phase 2 trial results.
The study, “CHOP versus GEM-P in previously untreated patients with peripheral T-cell lymphoma (CHEMO-T): a phase 2, multicentre, randomised, open-label trial,” was published in The Lancet Haemotology.
Currently, the front-line treatment for patients with peripheral T-cell lymphoma is a combination of cyclophosphamide, doxorubicin, vincristine, and prednisolone, also called CHOP chemotherapy.
However, for most patients, outcomes with CHOP are poor, with only 33-43% achieving complete remission and 38.5% living for five years or longer.
The regimen of gemcitabine, Platinol, and methylprednisolone (GEM-P) has shown promising response rates — 69-100% — in peripheral T-cell lymphoma patients who had failed to respond or relapsed after prior treatments.
The UK National Cancer Research Institute (NCRI) set out to investigate the potential benefits of GEM-P compared to CHOP in untreated patients with peripheral T-cell lymphoma.
The CHEMO-T trial (NCT01719835) started in March 2012, enrolled a total of 87 patients with peripheral T-cell lymphoma not otherwise specified (PTCL-NOS), angioimmunoblastic T-cell lymphoma, anaplastic lymphoma, kinase-negative anaplastic large cell lymphoma, enteropathy-associated T-cell lymphoma, or hepatosplenic gamma-delta T-cell lymphoma.
Patients were randomly assigned to receive the standard six cycles of CHOP chemotherapy every 21 days or four cycles of GEM-P every 28 days.
After a median follow-up of 27.4 months, 62% of patients in the CHOP group achieved complete or unconfirmed complete response, while only 46% of those receiving GEM-P reached the same outcome.
“Recruitment to the trial was closed early as there was strong evidence that the primary endpoint — to detect superiority of GEM-P over CHOP by a comparison of the CT-based complete responses and unconfirmed complete responses at end of treatment — would not be met,” investigators wrote.
The most common side effects in both chemotherapy regimens included reduced neutrophil levels, low platelet count, and fever. Two patients from the GEM-P regimen died during the study, both from lung infections.
“A superior upfront induction regimen is urgently required for patients with treatment-naive peripheral T-cell lymphoma, and future incorporation of novel drugs could enhance the efficacy of front-line therapy in this indication,” researchers wrote.
Ongoing trials (NCT01777152, NCT01796002, and NCT02561273) are already addressing this issue.
“In conclusion, although further studies are warranted, our Phase 2 randomised trial suggests that CHOP should, for the time being, remain the reference regimen for previously untreated patients with peripheral T-cell lymphoma and that GEM-P is best reserved for the relapsed and refractory setting at present,” researchers concluded.
