Immunotherapy may improve HSCT outcomes

Based on Kaplan-Meier estimates, the 1-year OS was 64% in the HSCT + ATIR101 group and 20% in the historical control group (P=0.0026).

GVHD

None of the patients in this trial (0/23) developed grade 3-4 GVHD upon infusion of ATIR101.

However, 3 cases of grade 2 acute GVHD were reported. One case occurred before ATIR101 infusion, and the other 2 cases had a delayed onset, at day 173 and day 247 post-HSCT (145 and 219 days post-ATIR101 infusion).

In the patient who developed GVHD before ATIR101 infusion, GVHD resolved quickly. The patient then received ATIR101 and did not experience any further GVHD.

“With this latest data, we can confirm the safety of ATIR101, without any incidents of grade 3-4 GVHD, significant reduction in transplant-related mortality, low relapse rates, and very good event-free survival, which we believe confirms the efficiency of photodepletion-based elimination of allo-reactive T cells,” Dr Roy said.

“Indeed, the data of patients receiving transplants with a haploidentical donor and an ATIR101 infusion are very similar to those from patients with a matched donor. As a doctor, I am very excited about this development and its potential to change patient fates.”

Dr Roy and his colleagues will continue to follow patients in this trial to collect further long-term outcome data.

Kiadis Pharma is planning to proceed with the development of ATIR101 as an adjunctive immuno-therapeutic treatment to a haploidentical HSCT for patients with acute leukemia, initiating a randomized phase 3 trial in the second half of 2016.

*Information in the abstract differs from that presented at the meeting.