Troy Wilson
Analyst · Leerink Partners. Your line is open
Thank you, Robert, and good afternoon everyone, and thanks for joining us today. We are excited to update you on our pipeline progress and provide highlights of our financial results. At Kura we are committed to realizing the promise of precision medicines for the treatment of cancer. Our pipeline consists of small molecule product candidates that target oncogenes and cancer signaling pathways and we seek to pair our product candidates with companion diagnostics to identify those patients most likely to respond to treatment. We will touch on each of our development programs in turn, but let's start with an update on our progress with our lead program, tipifarnib or Tipi for short. We are evaluating tipi in four Phase 2 trials. We are taking a disciplined step wise approach with a goal to confirm clinical activity to identify and validate biomarkers of activity to optimize the dosing schedule and to build a data package supporting advancement to our pivotal study. I’ll start first with an update on our progress with tipi in HRAS mutant squamous cell head and neck patients. Our Phase 2 trial in HRAS mutant patients was originally designed as a signal seeking study with a goal to validate HRAS as an oncogene and to test the hypothesis that we could use tipi as an inhibitor of HRAS farnesylation to drive meaningful anti-tumor activity. Initially the trial was designed to enroll two cohorts each of 11 evaluable patients with HRAS mutations; the first comprising patients with thyroid cancer, the second comprising with solid tumors, other than thyroid cancer. As per the trial protocol, at least two responses must be observed in the first stage of each cohort in order to proceed to the second stage. The thyroid cohort is ongoing in the first stage. As we previously reported among the 11 evaluable patients in the first stage of the second cohort we observed two objective responses out of three patients with squamous head and neck cancer and as a result we amended the protocol to enroll an additional seven head and neck patients in the second stage. As of the data call out on July 27, 2017, among the three head and neck patients who were enrolled in the first stage of the trial we have one patient with a PR who remained on study through cycle 20, and then came off study in cycle 21 due to progressive disease. As a reminder each cycle is 28 days. The second patient with the PR is ongoing in cycle 18 of treatment. The third patient experienced tumor shrinkage and prolonged disease stabilization and withdrew from the trial at cycle eight. Turning to the second stage of the trial, we had enrolled an additional three patients as of the data cut-off. Of those three patients our preliminary data shows that the first patient has also experienced a PR according to the resist criteria. And that patient is currently in cycle four. The second patient is in cycle two and was reported as having stable disease and the third patient is pending objective response assessment. In order to appreciate the potential significance for these results, it's important to consider the prognosis of individual patients. As we consider the outcome of the therapies the patients on our study received prior to entering our trial it's notable that none of these five patients were reported to have experienced an objective partial response on their prior line of therapy. And three of the five patients experienced only progressive disease on their prior line of therapy including one patient receiving pembrolizumab. Thus we so far have three confirmed partial responses out of five evaluable HRAS mutant squamous cell head and neck cancer patients and one additional patient currently pending evaluation. Enrollment is ongoing. In brief patients on the study who had failed therapy with cetuximab, with or without chemotherapy or immune therapy have achieved objective partial responses upon treatment with tipifarnib. Tipifarnib also continues to exhibit a manageable safety profile. We believe our results thus far are particularly impressive when we consider the current standard of care for patients with squamous cell head and neck cancer. Response rates for the three agents approved by the FDA in the second line are in the range of 13% to 16% and median overall survival is up to 7.5 months. In contrast we have observed confirmed partial responses in three of five evaluable patients and two of the responses have demonstrated durability beyond one year. This is extremely uncommon in the relapsed refractory setting of squamous head and neck cancer. We are continuing to recruit patients in both the U.S. and Europe. With the three additional patients and the additional confirmed partial response we’re reporting today, I want to remind you that as the trial was initially designed we need one additional response for the trial to be positive for the study protocol. Given the totality of the clinical data we have observed thus far, we are internally discussing the next steps for the program. Since our last call we have continued to increase our outreach to and education of physicians and patients. In July we announced a collaboration with Foundation Medicine to support patient identification and enrollment for our ongoing Phase 2 trial. Foundation Medicine is a leader and an innovator in applying comprehensive genomic profiling to the development of precision medicines and we are excited to partner with them as we seek to identify patients in the U.S. who may benefit from treatment with tipifarnib. Another important aspect of building value in drug discovery and development is the ability to maximize potential commercial value of product candidates. In July we announced the issuance of a U.S. patent directed to the use of tipifarnib in the treatment of patients with relapsed and/or refractory HRAS mutant squamous cell carcinomas of the head and neck. That patent has an expiration date of August 2036 and provides a significant increase to the protection that maybe offered by orphan exclusivity. We continue to pursue additional patent protection in the U.S. and other countries based on our clinical and preclinical data and our novel insights in the biomarkers of tipifarnib activity. The issuance of the patent illustrates the potential of that broader strategy to generate intellectual property related to tipifarnib and its use in human diseases. Now let me shift gears and talk briefly about what we are doing with tipifarnib in patients with peripheral T-cell Lymphoma or PTCL. In June we presented clinical and preclinical data for our PTCL trial at the Lymphoma meeting in Lugano -- Lugano and at EHA in Madrid. The data presented showed that seven out of the eighteen or almost 40% of patients in an unselected population with a median of four prior therapies, who were treated with tipifarnib, received clinical benefit in terms of either partial response or disease stabilization. Importantly we identified CXCL12 as a potential biomarker of tipifarnib activity in PTCL. Patients with elevated levels of CXCL12 gene expression had higher rates of objective response and experienced a median progression free survival of 190 days, a doubling of the expected PFS in this very advanced patient population. Having identified the CXCL12 chemokine as a potential biomarker we are now working to validate it as a biomarker of tipifarnib's activity in PTCL. We have extended our Phase 2 study to enroll 12 additional patients with angioimmunoblastic T-cell lymphoma or AITL, a subtype of PTCL characterized by high CXCL12 expression, with a goal to confirm these observations and validate the biomarker. We aim to release additional data on our efforts to validate the CXCL12 biomarker later this year. I want to turn now to our third Phase 2 trial in patients with Myelodysplastic Syndromes or MDS. We were motivated to investigate tipifarnib in MDS based on the previous Phase 2 clinical trial sponsored by Johnson and Johnson that demonstrated an encouraging level of activity for tipifarnib in patients with intermediate and high risk MDS. As just discussed data from our PTCL study identified CXCL12 as the potential biomarker of the activity of tipifarnib. CXCL12 is a chemokine known to induce homing of myeloid cells in the bone marrow. In the most extreme cases such as rare conditions with activating mutations in the CXCL12 pathway, patients course [ph] with persistent neutropenia. We hypothesized that the observation of isolated nuetropenia or neutropenia without myelo-suppression could be employed as a surrogate marker of high CXCL12 activity in the bone marrow and consequently sensitivity to tipifarnib. We retrospectively analyzed data from the previous Phase 2 clinical trial in MDS sponsored by Johnson and Johnson and observed that the majority of responders to tipifarnib were patients with neutropenia at study entry. Based on these data and the relationship between CXCL12, neutropenia and the activity of tipifarnib we are modifying our MDS study to test prospectively whether neutropenia at study entry could enrich the responses to tipi. We plan to enroll two cohorts of up to 18 patients each with a Simon two-stage design similar to our other trials. We will open the inclusion criteria to MDS patients of any risk group and modify the primary endpoint from transfusion independence to objective response which may provide a more rapid read out. The trial will enroll patients who have failed up to two prior therapies. Two responses are needed to move from the second stage of each cohort and the trial is positive with four or more responses in either cohort. We continue to anticipate having data from this trial in the first half of 2018. Our fourth Phase 2 trial with tipifarnib is in patients with Chronic Myelomonocytic Leukemia or CMML, a disorder of bone marrow stem cells, where an increase in white blood cells or monocytosis is a key feature of the disease. We continue to expect to have data from this trial to share in the first half of 2018. Now let me turn briefly to our other pipeline programs. We're developing KO-947 our small molecule ERK inhibitor as a potential treatment for tumors with disregulated activity of the mytogene activated protein kinase signaling pathway. We're currently conducting a Phase 1 dose escalation study for KO-947. The trial design includes the dose escalation, maximum tolerated dose expansion and one or more tumor specific extension cohorts. The trial is ongoing and we anticipate data in 2018. For our menin-MLL inhibitor program, we continue to assess potential of KO-539 in hematologic malignancies and solid tumor indications. We're excited about the novel mechanistic approach and the therapeutic opportunities that this innovative program may be able to pursue. That covers the update on our product candidate development programs. I'll now turn the call over to Heidi for a discussion of the financial results for the second quarter of 2017. Heidi?