Incyte dramatically ups the immuno-oncology combo ante

Incyte has propelled itself into the immuno-oncology premier league by revealing plans to initiate eight new phase III studies with its IDO1 inhibitor epacadostat and an anti-PD-1 antibody, bringing the total of such registration trials to nine. The plan covers six new studies with Merck & Co’s Keytruda and two new trials with Bristol-Myers Squibb’s Opdivo, and represents the most ambitious registrational expansion for any novel IO agent.

Although only the indications and settings have been disclosed at this point, it is possible that in two cases Incyte could find itself with parallel registration studies of Merck’s and Bristol’s agents. And, in a third case, it could end up conducting the first study that compares a combination with one anti-PD-1/PD-L1 agent with single-agent use of another (see tables below).

The ambitious move clearly cements epacadostat as the go-to IDO inhibitor for combining with checkpoint blockers, which has implications for companies with competing agents. Bristol even seems to have passed over its own early clinical-stage IDO inhibitor, BMS-986205, in favour of epacadostat.

Merck collaboration

Incyte and Merck are to initiate two studies of their combo in first-line NSCLC – in PD-L1-high and unselected patients; two in urothelial bladder cancer, and one each in renal cell carcinoma (RCC) and squamous cell carcinoma of the head and neck (SCCHN). The two companies already have one phase III under way (Keynote-202) in metastatic melanoma, as well as the large phase I/II study Keynote-037 in solid tumours.

Meanwhile, Incyte and Bristol are starting studies with Opdivo in first-line NSCLC and first-line SCCHN. In addition, an existing phase I/II study (Echo-204) in solid tumours will be expanded to include an anti-PD-1/PD-L1-relapsed/refractory melanoma cohort. All of the new studies will be 50/50 co-funded and run with the big pharma partner.

In NSCLC it seems logical that the study in PDL-1-high patients will test the combo against Keytruda monotherapy, which is indicated for first-line use at PD-L1 expression >50%. For Opdivo in this indication the new study will recruit “across the spectrum of PD-L1 expression”, suggesting that at least at high levels the comparison will also be made with Merck’s agent, although chemo could be appropriate for those with lower expression levels.

The design of the NSCLC studies, once revealed, will be particularly closely examined, given the pending readout of high profile IO-IO combo trials like AstraZeneca’s Mystic, and IO-chemo combos, such as Roche’s Impower-150.

Both Merck and Bristol have selected first-line SCCHN for new trials, so it is possible for similar trials with the two PD-1 agents to be conducted in parallel, testing perhaps against chemo plus Erbitux.

Meanwhile, the study in second-line bladder cancer might provide an opportunity to test the Keytruda combo directly against Roche’s Tecentriq, which is now a new standard of care in this setting. Of course, Merck might shortly obtain approval for Keytruda as monotherapy here on the basis of Keynote-045, so it could chose not to do this.

Leerink analysts said the expanded collaboration with Bristol was surprising since Merck had an exclusivity period as a result of its earlier phase III initiation in melanoma. However, they said this might have been circumvented by agreeing to examine different clinical questions in the two companies’ studies, which would be achieved through differences in the comparator arms.

One of the key factors that Merck and Bristol alike will have considered is potential changes in standards of care that could occur while the trials are under way. In all five indications targeted by the new studies there are many competing trials with anti-PD-1/PD-L1s, including Keytruda and Opdivo.

Incyte has several earlier phase I/II trials under way with epadocastat and other checkpoint inhibitors, including Astrazeneca’s durvalumab and Roche’s Tecentriq. It will be interesting to see if it can extend its portfolio of phase III partnerships to accommodate future phase III trials with other anti-PDL-1 companies.

To contact the writer of this story email Robin Davison in London at [email protected] or follow @RobinDavison2 on Twitter