Ali Fattaey
Analyst · Roth Capital Partners
Thank you, Dan. I also would like to reiterate our excitement with the R&D progress that we've been making. I believe this is the first time that Curis has had 2 drugs in the clinic at the same time. And this is an exciting time for us. And as Dan indicated, our partners as well making great strides with Erivedge and Debio 0932. So at the moment, we really look forward to all 4 of these programs, 2 our own and 2 from our partners, progressing in the clinic, which is very exciting for us. I'd like to start today with an update on our fully owned IAP antagonist drug candidates, CUDC-427, which as we've discussed before, targets mechanisms of evasion from programmed cell death or apoptosis. During the second quarter, we presented the results of the Phase I trial of CUDC-427 that was conducted by Genentech at the ASCO Annual Meeting in June. In this trial, encouraging clinical activity was seen, including complete responses in 1 ovarian cancer patient and 1 multi-lymphoma patient. We also believe this is the first time that responses, certainly complete responses, have been seen with monotherapy of any IAP antagonist that has gone into the clinic. In addition to the responses, stable disease was experienced by 8 of the 42 patients that were enrolled. Four of those patients have stable diseases longer than 3 months and 1 patient with upwards of 10 months of disease stabilization. CUDC also -- CUDC-427 also demonstrate a very favorable safety profile and was tolerable in the study. The PK profile of the drug was linear across all doses that was tested from 500 to 600 milligram dose on a daily basis, and biomarker modulation was also seen at nearly all doses in blood cells from patients and the available tumor tissue specimens that were examined. These results and the extensive preclinical data package that we got from Genentech are the basis for our development plans for CUDC-427, which includes trials focused on the ovarian and fallopian tube cancers, breast cancer and lymphoma, including evaluation of mild lymphomas. In this regard, we recently announced the initiation of a Phase I single-agent study in advanced malignancies to determine the maximum tolerated dose and the recommended Phase II dose of CUDC-427 using a continuous twice-daily regimen. Importantly, this trial is designed to enroll ovarian and fallopian tube cancer patients in its expansion cohort. Supported by the extensive preclinical data, we are also projecting initiation of the Phase Ib2 study with CUDC-427 in combination with gemcitabine or Xeloda in patients with HER2-negative breast cancer during this third quarter. This trial is expected to enroll patients that are both triple negative breast cancer, as well as estrogen receptor positive breast cancer patients. Lastly, we expect to initiate a third trial with this drug using the CUDC-427 to treat advanced lymphomas, which will include patients with known alterations in the IAP pathway, such as certain MALT lymphomas, as well as certain forms of aggressive lymphomas. We look forward to providing further updates regarding the study designs and specific subpopulations of patients for the upcoming trials in the coming months. Now I'd like to turn to our second proprietary drug candidate, CUDC-907, which by design is a dual targeted agent with potent PI3 kinase alpha, delta and to some extent beta inhibitory activity, but spares PI3 kinase gamma. The drug also targets the key HDAC enzymes 1, 2, 3, specifically 6 and HDAC10. CUDC-907 is being tested in an ongoing Phase I dose escalation trial in patients with advanced lymphomas and multiple myelomas. We've seen very encouraging drug exposure and also a unique metabolism profile of CUDC-907 in patients. This profile is very similar to what we observed in rodent animal models but we did not observe in dog models. Namely in all patients, the dual inhibitory parent molecule, CUDC-907, is metabolized into 2 forms, M1 and M2 forms, with the M2 metabolite retaining potent PI3 kinase inhibitory activity. Interestingly, whereas the parent CUDC-907 molecule appears to be relatively short-lived in the plasma from patients, with a half-life in order of a few hours, the M2 metabolite appears to have a rather long half-life, in the order of at least a day, possibly longer. Based on this PK and metabolism profile, the current emerging picture for us is that the administration of CUDC-907 orally to patients should result in a potent but relatively brief period of HDAC inhibition, which could provide prolonged PD effect, and at the same time, a sustained inhibition of PI3 kinase activity through the buildup of the potent and stable M2 metabolite. In this trial, so far, from the safety perspective, common adverse events that we've observed have included reversible thrombocytopenia and gastrointestinal effect, including diarrhea, which are known side effects associated with HDAC and some PI3 kinases as well. There's been no unexpected toxicity thus far in the trial. In terms of preliminary clinical activity, one patient each from the initial 2-dose escalation cohorts continue on treatment with disease stabilization, and this includes 1 patient with multiple myeloma in treatment cycle 9 that's beyond 6 months of treatment at this point, and a patient with diffuse large B-cell lymphoma or DLBCL in treatment cycle 5. I would like to caution that these are early PK, safety and activity results represented by a small number of patients and also indicates that multiple myeloma and DLBCL were predicted as potential cancer indications of interest for us based on our preclinical results prior to the trial start, and they fit very nicely with the mechanism of action of this drug as well. As I indicated earlier, drug exposure is very encouraging for us and the half-life of the M2 metabolite is relatively long. Therefore, based on this observed PK profile of the M2 metabolite and parent and some of the observed side effect profile, we've now implemented certain modifications to the trial protocol. This includes examination of other dosing schedules to fit the M2 metabolite's half-life better and in parallel, with the original continuous dosing regimen. Therefore, the study will now also enroll patients on either 3x or twice-weekly dosing regimens, and all 3 regimens will be ongoing in parallel. The PK profile of the parent CUDC-907 drug and the M2 metabolite, as we indicated, appear to be well-suited for intermittent dosing and may also allow us to maximize the dual activity of the drug and hence, provide greater anticancer activity while minimizing the potential occurrence of adverse events. Given the current status of enrollment, we expect to report preliminary data from this trial at a scientific conference later this year. I would, once again, like to caution that all the clinical observation we discussed today are based on a very small number of patients enrolled in the Phase I trial thus far and they need to be further analyzed in larger groups of patients. Also as a reminder, CUDC-907 is being developed in collaboration with the Leukemia & Lymphoma Society, or LLS, and during the second quarter, we earned a $550,000 milestone under our collaboration for the achievement of clinical development objective. Finally, we are also planning to start another Phase I trial with CUDC-907 in solid tumor patients in the coming months. We will provide additional details regarding this trial as we get closer to its initiation. I'll now turn the call back to Dan, to provide an update on our partnered programs. Dan?