SELLAS Life Sciences Group has received orphan drug designation (ODD) from the US Food and Drug Administration (FDA) for SLS009, a new CDK9 inhibitor aimed at treating relapsed/refractory Peripheral T-cell Lymphomas (PTCL).
Currently, SLS009 is under evaluation in a Phase Ib/II trial for patients with r/r PTCL. The study, which is open-label and single-arm, plans to enrol up to 95 patients to assess the drug’s safety and efficacy.
If successful, the results may lead to a registrational study. This PTCL trial is fully funded by GenFleet Therapeutics and is being carried out in China.
The Phase I trial’s dose-escalation segment for r/r haematological malignancies has shown SLS009 to be safe and potentially effective.
Notably, clinical responses were seen in 36.4% of PTCL patients, including one with a complete metabolic response ongoing for over 62 weeks, and another with a complete response by CT scan ongoing for over 24 weeks.
These results are particularly encouraging as the current standard of care, belinostat, had a 25.8% response rate in its pivotal Phase II study for a similar patient group.
Moreover, patients who achieved a complete response in the SLS009 study had previously undergone treatment with HDAC inhibitors.
SELLAS president and CEO Angelos Stergiou said: “In the recently completed dose-escalation portion of the Phase I trial in r/r haematological malignancies, SLS009 achieved clinical responses in PTCL including two patients reaching complete response.
“We are excited to see a favourable safety profile, strong initial efficacy signals, and evidence of anti-tumour activity across the Phase 1 study as well as the ongoing Phase II studies.
“With both designations in hand, we look forward to advancing the development of SLS009 and continuing to work closely with regulators with the goal of delivering this treatment to those who may benefit from it.”