Troy Wilson
Analyst · Leerink Partners. Your line is now open
Thank you, Pete. At Kura, we are committed to realizing the promise of precision medicines and ultimately to helping patients with cancer lead better, longer lives. We set out to assemble a pipeline of small molecule drug candidates that target oncogenes and cancer signaling pathways then pair them with molecular or cellular diagnostics to identify those patients most likely to respond to treatment. Now less than 4 years from our founding, we are on the verge of our first registration directed study with our lead drug candidate, tipifarnib. Tipifarnib is potent, selective and orally bioavailable inhibitor of the farnesyl transferase enzyme that we licensed from Janssen. We are currently evaluating tipifarnib in multiple solid tumor and hematologic indications. Our most advanced indication is in HRAS mutant head and neck squamous cell carcinomas or HNSCC. In March, we provided a regulatory update following a successful end-of-Phase 2 meeting with the FDA. Based on the clinical activity we have observed in our ongoing Phase 2 RUN-HN study as well as encouraging feedback from the agency, we are now planning to conduct a global registration-directed trial of tipifarnib in at least 59 patients with HRAS mutant HNSCC, who have received prior platinum-based therapy. We are calling this our AIM-HN trial. The primary endpoint of AIM-HN is overall response rate. Our trial design has approximately 80% power to detect the difference between a no hypothesis of 15%, which is the point estimate of second line therapy ORR for recurrent and metastatic disease and 30%, an ORR considered of interest. Based on the feedback we have received from FDA, we believe this trial, if positive, could support an application for accelerated approval. In addition, we were encouraged that FDA did not require patients to have received second – sorry to have received prior second line therapy, including immune therapy, despite the fact that several agents are approved for use in the second line in the U.S. This allows us to enroll any post-platinum patients independently of line of treatment and gives us maximum flexibility in terms of enrolling patients both in the U.S. and abroad. Finally, given the extensive clinical data previously generated by Janssen and based on input from the agency, we believe our safety database should be adequate to support an NDA filing if the AIM-HN study is positive. We are planning to initiate our AIM-HN trial in the second half of this year. We anticipate the trial will require fewer than 100 clinical sites worldwide and take approximately 2 years to enroll. Pending a final statistical analysis plan, the trial could need as few as 15 confirmed responses in order to reject the null hypothesis and meet its primary efficacy endpoint. Thus although we are projecting a 2-year enrollment period, the trial has the potential to become positive prior to the completion of enrollment as was the case for our RUN-HN trial. In conjunction with the AIM-HN trial, we are also preparing to initiate SEQ-HN, a multi-center non-interventional screening and outcome study. There are two primary goals of SEQ-HN. The first is to facilitate the identification of patients with HRAS mutations for potential enrollment into our AIM-HN trial. The second goal is to characterize the natural history of patients with recurrent or metastatic HNSCC with HRAS mutations. We know, for example, that the response rates for the three agents currently approved for treatment of HNSCC in the second line are in the range of 13% to 16%, but the response rate for the HRAS mutant population is unknown. Although we are using a null hypothesis of 15% in our AIM-HN trial, none of the first 9 patients enrolled in our ongoing Phase 2 trial experienced a response on their last prior line of therapy. Thus, the response rate of HRAS mutant patients to the standard of care may be less than 15%. Data in the literature have already shown a lesser response rate to standard first line therapy and poor prognosis in HRAS mutant HNSCC patients as compared to HRAS wild-type patients and we expect to confirm those observations in our dataset. For that purpose, SEQ-HN is designed as a case-control study matching our AIM-HN patients with HRAS mutation against those who are HRAS wild-type using factors such as age, line of therapy and type of treatment. This will provide us with a better understanding of the natural history of patients with HRAS mutations and their medical need. We took this innovative, parallel design SEQ-HN and AIM-HN to the FDA and we were very encouraged by the feedback we received. If our AIM-HN trial is positive, the agency is willing to consider the totality of the data, including the results of AIM-HN, SEQ-HN and our ongoing RUN-HN trial to determine the appropriateness and nature of an approval and post-approval commitments. We received similar input in two national scientific advice meetings in Europe. Rather than conducting SEQ-HN and AIM-HN as two separate studies, we have now elected to run both studies under a single clinical protocol for operational efficiencies. We are currently in the process of finalizing the updated protocol and expect to initiate SEQ-HN concurrently with AIM-HN in second half of the year. An important element of our development strategy for tipifarnib in HNSCC is our ability to identify patients with HRAS mutations. This is the same challenge faced in the development of other targeted therapies, including inhibitors of track, Ross 1 and rat, namely the need to screen and identify relatively rare patients among the overall population. In order to avoid any delay as a result of the new study protocol, we are already triggering many of the HRAS sequencing activities included in SEQ-HN, including contracted academic laboratories and certainly tumor DNA sequencing facilities in the U.S., Europe and Asia and developing patient and physician directing materials in collaboration with the head and neck cancer alliance and academic groups. We are also developing a travel assistance program for patients, that is designed to support our ongoing RUN-HN and also support AIM-HN. We remain squarely focused on enrollment and will continue to pursue opportunities to support patient identification and screening as we prepare for the initiation of AIM-HN and SEQ-HN. Meanwhile, development activities are underway to expand the potential opportunity for tipifarnib in solid tumor indications with HRAS mutations beyond HNSCC. We have expanded our ongoing Phase 2 clinical trial of tipifarnib in HRAS mutant solid tumors to include an exploratory cohort of patients with other HRAS mutant squamous cell carcinomas. Given that the majority of investigators in our ongoing RUN-HN trial specialized in head and neck cancers, we expect this third cohort to enroll primarily patients with cutaneous squamous cell carcinomas that are also seen in head and neck clinics. We also recognized the potential opportunity for tipifarnib in HRAS mutant long squamous cell carcinoma a histology with a similar genetic pattern as HNSCC. Just last month at AACR, we presented new data showing that tipifarnib is highly active in preclinical models of HRAS mutant lung squamous cell carcinoma. To evaluate this opportunity, we are collaborating with the Spanish Lung Cancer Group, a cooperative group that consist of more than 150 public and private oncology centers in Spain on a proof-of-concept trial of tipifarnib in HRAS mutant lung squamous cell carcinoma. We anticipate this investigator-sponsored trial to initiate later this year. We continue to be very encouraged by the clinical and preclinical data we have generated supporting the potential of tipifarnib as a treatment for solid tumors characterized by HRAS mutations. Our goal is to generate a data package to support an application for marketing approval in HRAS mutant HNSCC as soon as possible while we work to broaden its potential use to include other diseases of high unmet need. Now, let’s turn our attention to the opportunity for tipifarnib in hematologic malignancies, which represents an important and exciting second major focus of our development strategy with tipifarnib. At ASH in December, we presented new findings that identified activation of the CXCL12 pathway and bone marrow homing of myeloid cells as potential biomarkers of tipifarnib’s activity in certain hematologic malignancies, including PTCL, MDS and myeloid neoplasias CML and AML. Based on these observations, we are now working to prospectively validate potential biomarkers in each of our three ongoing Phase 2 trials. In PTCL, we are evaluating tipifarnib in patients with angioimmunoblastic T-cell lymphoma, or AITL as well as patients with PTCL who have the absence in a single nucleotide variation in the 3-prime untranslated region of the CXCL12 gene. Our MDS study includes the cohort of patients with neutropenia at study entry and is evaluating CXCL12 pathway biomarkers as a method of patient enrichment. Finally, you may recall, we announced at ASH, our Phase 2 study of tipifarnib in CMML has achieved its primary efficacy endpoint. Although the results were preliminary, we observed a signal that supported the use of CXCL12 pathway biomarkers to stratify CMML patients who may benefit from treatment with tipifarnib. On the basis of that data as well as our retrospective analysis of previous studies of tipifarnib and AML conducted by Janssen, we have amended our Phase 2 trial in CMML to comprise MDS/MPN overlap syndrome, a group of myeloid disorders that include CMML and the cohort of relapsed refractory AML patients with CXCL12 pathway biomarkers. Our strategy for tipifarnib in hematologic malignancies is to replicate the approach that has served us well in our ongoing trial in HRAS mutant HNSCC. Specifically, we are looking to confirm the clinical activity of tipifarnib, validate our biomarker hypotheses, secure patent and/or regulatory exclusivity, optimize dosing schedule for each disease and generate clinical data that supports advancement to one or more registration-enabling studies. In keeping with that strategy, we recently announced the issuance of U.S. patent 9,956,215 methods of treating cancer patients with farnesyl transferase inhibitors. Similar to our recently issued patent covering the use of tipifarnib in HRAS mutant HNSCC, the 215 patent provides coverage of the use of tipifarnib as a method for treating patients with CXCL12 expressing PTCL or AML. Moreover, issuance of the 215 patent reinforces our commitment to unlock the value of tipifarnib in genetically defined patient populations. Our goal is to provide initial data in one or more biomarker enriched hematological indications by the end of 2018. Now, let’s quickly turn our attention to our two emerging pipeline programs beginning with our ERK inhibitor KO-947. We are advancing KO-947 as a potential treatment for patients with tumors that have dysregulated activity due to mutations or other mechanisms in the MAP kinase pathway. Our Phase 1 dose escalation trial of KO-947 in solid tumors is ongoing. We are working to define a dose in schedule that will enable us to evaluate KO-947 in genetically selected patients whose tumors are sensitive to ERK inhibition. In that regard, last month at AACR, we presented preclinical data for KO-947, including the identification of 11q13 amplification as a potential biomarker of activity for KO-947 in squamous cell carcinomas. Amplification of chromosomal region 11q13 is a common genetic alteration in squamous cell carcinomas comprising approximately 20% of HNSCC and approximately 50% of esophageal squamous cell carcinoma. We are also advancing KO-539, a potent in selective small molecule inhibitor of the menin-MLL interaction that has demonstrated potential anti-tumor activity in genetically defined subsets of acute leukemia, including those with oncogenic driver mutations in NPM1 and DNMT3A. Together with the mixed lineage leukemias, these mutations represent approximately half of diagnosed cases of AML. Pending successful completion of IND-enabling studies, we expect to submit an IND application for KO-539 in late 2018 or early 2019. This covers the update on our development programs. I will now turn the call over to Heidi for a discussion of the financial results for the first quarter of 2018.