Acetylon Pharmaceuticals has begun patient enrolment in a new Phase 1b trial of rocilinostat (ACY-1215) in combination with Celgene’s revlimid (lenalidomide) and dexamethasone for patients with multiple myeloma.

The company also announced that the rocilinostat combination study with Millennium Takeda’s Velcade (bortezomib) and dexamethasone has advanced into Phase 1b.

Rocilinostat is an oral Class II histone deacetylase (HDAC) inhibitor selective for the intracellular enzyme HDAC6, leading to inactivation of the aggresome pathway for degradation of damaged proteins.

Acetylon president and chief executive officer and co-founder Walter Ogier said Celgene’s recent investment in Acetylon has allowed the company to expand its clinical development programme to evaluate the safety and potential anti-tumour activity of rocilinostat in a new Phase 1b trial in an all-oral combination regimen with Revlimid, plus dexamethasone.

"This new clinical trial will enable us to study whether selective HDAC6 inhibition, which triggers apoptosis in malignant cells, may have a synergistic effect when combined with Revlimid and dexamethasone to treat patients who are relapsed and relapsed/refractory with multiple myeloma," Ogier added.

The primary outcome of the Phase 1b trial of ACY-1215 in combination with revlimid (lenalidomide) and dexamethasone is to establish the optimal dose of rocilinostat over a 28-day treatment cycle.

Rocilinostat will initially be administered orally on days 1-5 and 8-12 of the 28-day dosing schedule and the additional regimens may be evaluated based on the outcome of the first schedule.

The Phase 1b trial of ACY-1215 in combination with velcade (bortezomib) and dexamethasone is enrolling patients with relapsed or relapsed/refractory multiple myeloma in a 21-day treatment cycle to determine the maximum tolerated dose of rocilinostat (ACY-1215) in combination with Velcade (bortezomib) and dexamethasone, followed by up to five additional sequential cycles of treatment.

To determine the maximum tolerated dose of rocilinostat as monotherapy, followed by up to five additional sequential cycles of treatment, the Phase 1a portion of the trial continues to enrol the same group of patients in a 21-day treatment cycle

Acetylon clinical development vice president Catherine Wheeler said, "Rocilinostat has been well-tolerated by patients in our ongoing Phase 1a monotherapy trial, which has allowed us to accelerate initiation of the Phase 1b portion of the trial, combining rocilinostat treatment with Velcade plus dexamethasone."