Curis (CRIS) early in August added two new cohorts to its ongoing Phase I study of CUDC-907 and increased target enrollment in the study from 36 to 117 patients. In mid-July, PropThink suggested owning CRIS almost exclusively for CUDC-907, a dual HDAC and PI3K inhibitor, and the news that the trial has been expanded to evaluate more patients and more treatment arms is encouraging. Particularly noteworthy is that the trial was expanded without including new trial sites, thus the supposition is that investigators at the existing sites are seeing encouraging activity and are interested in expansion of the trial.
The Phase I trial (NCT01742988) originally included a single arm. Patients received ascending doses (dosage doubled between cohorts) of CUDC-907, beginning with continuous, once-daily -907 at 30mg. The second cohort began dosing at 60mg, and a third cohort, given that no dose-limiting toxicities materialize, will begin at 120mg. The trial was designed to enroll 36 patients.
Now, Curis has added two more arms to the ongoing study: a 2x/week arm of -907 at 60-180 mg/day on Mondays and Thursdays; and a 3x/week arm of-907 at 60-180 mg/day on Mondays, Wednesdays and Fridays. Enrollment and dosing will increase in a 3+3 manner; in the absence of a dose-limiting toxicity, subjects will be treated for a minimum of 21 days before a new cohort begins at a higher dose.
Recall that Curis is now on the second treatment cohort (60mg) in the original, single arm of the study: one multiple myeloma patient in cohort 1 (30mg) continues to receive treatment (cycle 9) and one DLBCL patient in cohort 2 (60mg) is on cycle 5.
The full list of changes to the study protocol can be seen here.
Overall, the addition of new dosing regimens in the study is bullish for CRIS, suggesting that investigators are seeing activity in early cohorts. Our investment thesis is based almost exclusively on CUDC-907 given its differentiated profile as a dual HDAC and PI3K inhibitor. Read more in our prior report.