Conference Coverage

Combo emerges as bridge to transplant in rel/ref PTCL


 

REPORTING FROM TCLF 2019

– The combination of duvelisib and romidepsin is active and can provide a bridge to transplant in relapsed or refractory peripheral T-cell lymphoma (PTCL), according to researchers.

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In a phase 1 trial, duvelisib plus romidepsin produced an overall response rate (ORR) of 59% in patients with PTCL. Sixteen patients achieved a response, nine had a complete response (CR), and six complete responders went on to transplant.

“So we think that you can achieve remission deep enough to then move on to a potentially curative approach,” said study investigator Neha Mehta-Shah, MD, of Washington University in St. Louis.

She and her colleagues evaluated romidepsin plus duvelisib, as well as bortezomib plus duvelisib, in a phase 1 trial (NCT02783625) of patients with relapsed or refractory PTCL or cutaneous T-cell lymphoma (CTCL).

Dr. Mehta-Shah presented the results at the annual T-cell Lymphoma Forum.

She reported results in 80 patients­ – 51 with PTCL and 29 with CTCL. The patients’ median age was 64 years (range, 28-83), and 57% of the study population were men. Patients had received a median of 3 (range, 1-16) prior therapies, and 16% had received a prior transplant.

Treatment

Dr. Mehta-Shah noted that patients and providers could choose whether patients would receive romidepsin or bortezomib.

Patients in the romidepsin arm received romidepsin at 10 mg/m2 on days 1, 8, and 15 of each 28-day cycle. Patients in the bortezomib arm received bortezomib at 1 mg/m2 on days 1, 4, 8, and 11 of each cycle.

Duvelisib dosing was escalated, so patients received duvelisib at 25 mg, 50 mg, or 75 mg twice daily.

In the bortezomib arm, there was one dose-limiting toxicity – grade 3 neutropenia – in a patient who received duvelisib at the 25-mg dose. There were no dose-limiting toxicities in the romidepsin arm.

The researchers determined that the maximum tolerated dose (MTD) of duvelisib was 75 mg twice daily in the romidepsin arm and 25 mg twice daily in the bortezomib arm.

Lead-in phase

The study also had a lead-in phase during which patients could receive single-agent duvelisib.

“Because the original phase 1 study of duvelisib did not collect as many prospective tumor biopsies or on-treatment biopsies, we built into this study a lead-in phase so that we could characterize on-treatment biopsies to better understand mechanisms of response or resistance,” Dr. Mehta-Shah said.

Patients and providers could choose to be part of the lead-in phase, she noted. Patients who did not achieve a CR during this phase went on to receive either combination therapy, which was predetermined before the monotherapy began.

There were 14 patients who received duvelisib monotherapy at 75 mg twice daily. Four of them achieved a CR, and three had a partial response (PR). Ten patients went on to receive romidepsin as well. One of them achieved a CR, and three had a PR.

There were 12 patients who received duvelisib monotherapy at 25 mg twice daily. Three of them achieved a CR, and two had a PR. Nine patients went on to receive bortezomib as well. This combination produced one CR and two PRs.

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