Nektar Therapeutics’ (NASDAQ:NKTR) NKTR-214 potential combination with Syndax Pharmaceuticals’ (NASDAQ:SNDX) entinostat has drawn mixed expert response on its potential to deliver efficacy impact in metastatic melanoma.
Although the combination has a reasonable complimentary mechanism, entinostat’s available data in melanoma is underwhelming, experts explained. They said the combination could stimulate an antitumour response by exaggerating an immune system reaction. However, latest Phase I/II data showing entinostat delivering 18% overall response rate (ORR) is low for melanoma, when the success bar is north of 50%.
On 30 May, Syndax and Nektar announced a nonexclusive, clinical collaboration to evaluate safety and efficacy of NKTR-214 with entinostat in metastatic melanoma. The Phase Ib portion of the trial will aim to establish safety and a recommended dose for the combination, while the Phase II is designed to assess efficacy, as defined by ORR and durability of response. A trial start date has yet to be disclosed.
Syndax’s earlier Phase Ib/II ENCORE 601 trial (NCT02437136) data release investigating entinostat with Merck's (NYSE:MRK) Keytruda (pembrolizumab) at ASCO in June led to shares dropping by 12%, with the Syndax/Nektar partnership announcement leading to shares increasing by 1%. Before ASCO data was released, analysts estimated entinostat to reach sales of USD 559m by 2020.