Wei Lin
Analyst · Guggenheim. Your line is now open
Thank you, Steve. I'll start by providing monotherapy updates across our portfolio. Beginning with daraxonrasib, our most advanced RAS(ON) inhibitor. This multi selective inhibitor has demonstrated compelling results across multiple tumors, including lung cancer, and is currently being evaluated in a Phase 3 registrational study for patients with previously treated non-small cell lung cancer. We're currently activating study sites for RASolve 301. The study randomized approximately four twenty patients to either daraxonrasib monotherapy or docetaxel. These patients must have received either one or two prior lines of therapy, including immunotherapy and platinum-based chemotherapy given either concurrently or sequentially. RASolve 301 incorporates a nested design with a primary analysis being performed in the core population of non-small cell lung cancer patients with RAS G12X mutations, excluding G12C. Extended population will incorporate all patients with RAS mutant non-small cell lung cancer, including those with tumors harboring G12C, G13 or Q61 mutations. The study has dual primary endpoints of progression free survival and overall survival. Moving to G12D non-small cell lung cancer. We've previously shown promising activity by daraxonrasib in patients with these tumors and the ongoing RASolve 301 recreational study includes such patients. Last month at AACR, initial clinical results were presented for zoldonrasib, our RAS(ON) G12D-Selective Covalent Inhibitor from a non-small cell lung cancer cohort. I'll walk you through these data. Zoldonrasib was well tolerated with manageable and predominantly low-grade treatment related adverse events as shown on the safety table. As of the December 02, 2024, data cutoff, at the 1200 mg once daily dose, two Grade 3 adverse events were reported among ninety patients with only two dose interruptions and no dose reductions. Zoldonrasib achieved a favorable mean dose intensity of 98%. Zoldonrasib monotherapy at the 1200 mg daily dose demonstrated encouraging antitumor activity. The waterfall plot shows the best percentage change in tumor size for patients with non-small cell lung cancer who received their first dose of zoldonrasib at least eight weeks prior to the data cutoff date. The objective response rate was 61%, including patients with a confirmed response or a response that was pending confirmation. The disease control rate was 89%. We'll continue following these patients to define durability. Now I'll move to our RAS(ON) G12C mutant selective covalent inhibitor, elironrasib, in non-small cell lung cancer. We reported the first clinical data on elironrasib in non-small cell lung cancer at the Triple meeting in 2023. And today, I'll share updated elironrasib monotherapy data that includes more patients and longer follow-up as a foundation for combination strategies to move into first-line metastatic and eventually earlier lines of non-small cell lung cancer. As of the April 07, 2025 data cutoff, 36 patients who had received prior treatment with standard care were treated with elironrasib monotherapy at 200 mg twice daily. Elironrasib was generally well tolerated with treatment related adverse events consistent with previously reported data. The most frequently observed treatment-related adverse events were gastrointestinal and asymptomatic QTc prolongation. Elironrasib achieved a favorable mean dose intensity of 94%. Here, we show the clinical activity in the same 36 patients treated with elironrasib monotherapy, the dose of 200 mg twice daily. The objective response rate in these patients was 56%. The disease control rate was 94%. The estimated median progression-free survival in these patients was 9.9 months. I'll now cover our combination of clinical development to enable our goal of improving treatment outcomes for patients with RAS mutant non-small cell lung cancer in the first-line metastatic setting. The need for improved treatment options for patients with metastatic non-small cell lung cancer remains high. In the first-line setting, two regimens are widely used globally. Pembrolizumab plus chemotherapy is the most commonly used treatment for all patients regardless of their tumor PD-L1 expression status as measured by Tumor Proportion Score or TPS. And pembrolizumab monotherapy is the preferred regimen in patients with TPS greater than or equal to 50%, which accounts for about 1/3rd of patients with non-small cell lung cancer. While the introduction of immunotherapy has been transformative for patients with non-small cell lung cancer, especially those with high PD-L1 expression. As the data in this table indicate, non-small cell lung cancer remains a disease with high unmet need. Because among the approximately 2/3rd of patients who have tumors with lower or no PD-L1 expression, even the best available standard care has not resulted in reported response rates above 40%. In RAS mutant non-small cell lung cancer in the second-line and beyond, treatment is generally either the chemotherapy docetaxel or a KRAS G12C(OFF) inhibitor. As illustrated in the table, reported response rates for docetaxel have been less than 15%, even with the commercially available KRAS G12C(OFF) inhibitors of sotorasib and adagrasib. Reported patient outcomes have been modest with response rates of approximately 30%. Combinations are likely to remain a foundation of first-line metastatic treatment for non-small cell lung cancer. And our main objective is to determine the best way to bring targeted RAS inhibitors into combination with immunotherapy for the first-line treatment of RAS mutant non-small cell lung cancer. These figures from preclinical experiments illustrate two concepts that guide our clinical approaches. The first concept shown on the left is that 2 RAS(ON) inhibitors can be combined to increase anti-tumor activity. In this experiment with a KRAS G12C non-small cell lung cancer model, either elironrasib or daraxonrasib alone significantly increased progression-free survival compared to control as measured by time to tumor doubling. Notably, the combination of elironrasib plus daraxonrasib prolong progression free survival even further, indicating additive durability from the RAS(ON) inhibitor doublet. The second concept shown in the experiment on the right is that this RAS(ON) inhibitor doublet significantly synergizes with immunotherapy. In this experiment, we used an refractory KRAS G12C non-small cell lung cancer tumor that was unresponsive to anti PD-1 inhibitor alone and only partially responsive to anti PD-1 combined with either RAS(ON) inhibitor. Essentially, no progression was seen in this model during 100 days of treatment with anti PD-1 combined with the RAS(ON) inhibitor doublet. Encouraged by preclinical results of this sort, I will now describe new clinical data from our evaluation of pairwise combinations of daraxonrasib plus pembrolizumab, elironrasib plus pembrolizumab and elironrasib plus daraxonrasib that suggest these concepts may translate in patients with KRAS G12C non-small cell lung cancer. The first combination data set I'll review is daraxonrasib plus pembrolizumab with or without chemotherapy. Daraxonrasib plus pembrolizumab with or without chemotherapy has been generally well tolerated in patients with non-small cell lung cancer. Previously, we showed acceptable tolerability for the combination of daraxonrasib with pembrolizumab in later line patients. And with further follow-up, the tolerability profile in those patients has remained stable. Today, we're focusing on patients with first-line disease. While the follow-up is shorter for patients in the first-line setting, the tolerability profile of daraxonrasib plus pembrolizumab is consistent with what has been observed in the second-line setting with or without the addition of chemotherapy. No new safety signals were seen and the overall tolerability profile is consistent with that of daraxonrasib plus standard care agents. Rash, gastrointestinal toxicities and stomatitis mucositis remain the most commonly observed adverse events for daraxonrasib, and neutropenia and thrombocytopenia emerged with addition of chemotherapy. The tolerability profile supports the further development of daraxonrasib plus pembrolizumab with or without chemotherapy. Dose reductions and discontinuations of daraxonrasib or pembrolizumab in this combination were modest. Daraxonrasib achieved a favorable mean dose intensity of 93% in combination with pembrolizumab and 90% with additional chemotherapy. Only a limited number of first-line patients have had sufficient follow-up to have had a tumor assessment, we're encouraged by the antitumor activity seen to date. In the left figure, patients had tumors with TPS greater than or equal to 50% and were treated with daraxonrasib plus pembrolizumab, consistent with the population who would have received pembrolizumab monotherapy of standard care. Of these 7 efficacy valuable patients who had undergone at least one tumor assessment, 86% of these TPS greater than or equal to 50% patients had a RECIST response and all had achieved disease control and remained on treatment. While the data set will continue to evolve with addition of more patients and longer follow-up, this is a very encouraging start. In the figure on the right, patients with TPS less than 50% were treated with daraxonrasib plus pembrolizumab and chemotherapy, consistent with the roughly 2/3rd of first-line patients who would likely receive pembrolizumab plus chemotherapy of standard care. Of the 10 efficacy valuable patients who had undergone at least one scan, 60% of these TPS less than 50% patients had a RECIST response and 90% achieved disease control. These data support the continued development of daraxonrasib plus standard care in first-line RAS mutant non-small cell lung cancer. I'll now touch on the elironrasib plus pembrolizumab combination. Demonstrating the safety of this combination is important as we take a pairwise approach toward our goal of developing a chemotherapy sparing triplet combination of elironrasib, daraxonrasib and pembrolizumab in patients with first-line metastatic KRAS G12C non-small cell lung cancer. We previously showed acceptable tolerability for the elironrasib plus pembrolizumab combination in the second-line plus setting. With further follow-up of few of those patients, we have not observed an increase in additive toxicity. Today, we'll focus on initial results in patients with first-line non-small cell lung cancer. As of the February 10, 2025 data cutoff, the combination of elironrasib with pembrolizumab showed a well-tolerated profile with few Grade 3 or higher treatment related adverse events. No new safety signals were observed. This tolerability profile translated to an acceptable dose modification rate in either the second-line or first-line setting. And elironrasib maintained a favorable mean dose intensity of 85%. The combination of elironrasib with pembrolizumab showed encouraging preliminary antitumor activity. Among 5 efficacy valuable patients with first-line non-small cell lung cancer and a TPS greater than or equal to 50%, all achieved a RECIST response. Our development strategy in the first-line RAS G12C mutant non-small cell lung cancer is to replace the standard care with the triplet regimen of elironrasib, daraxonrasib and pembrolizumab as a chemo sparing regimen. I've just shown data supporting the combinability and anti-tumor activity of daraxonrasib plus pembrolizumab and elironrasib plus pembrolizumab. The third pairwise combination needed to support this triplet regimen is the RAS(ON) inhibitor doublet of elironrasib plus daraxonrasib. This RAS(ON) inhibitor doublet concept is supported by strong results in preclinical models, including models that refractory to monotherapy approaches. In these preclinical models, deep and durable responses are seen in RAS(ON) inhibitor doublets. In December 2024, we shared initial clinical data for the RAS(ON) inhibitor doublet of elironrasib plus daraxonrasib to establish the mechanistic proof of principle for this combination. We evaluated a challenging population of colorectal cancer patients who had been previously treated with not only standard care chemotherapy, but also with KRAS G12C(OFF) inhibitors and anti-EGFR antibodies. These early results demonstrated an acceptable tolerability profile along with encouraging antitumor activity in a very difficult to treat patient population. These results provided strong rationale for continued development of this RAS(ON) inhibitor doublet approach across tumor types and lines of therapy. Today, I'll share initial dose finding data from this RAS(ON) inhibitor doublet in patients with non-small cell lung cancer. The data in this table demonstrate the combinability of elironrasib with daraxonrasib with a tolerability profile that is largely consistent with that of daraxonrasib itself. Even with longer follow-up, hepatotoxicity did not emerge as a safety signal in this larger cohort of lung cancer patients. QT prolongation of ECG was not symptomatic and is not common with a Grade 3 rate of only 3%. This tolerability profile translated to no treatment discontinuations and a favorable mean dose intensity of 95% for elironrasib and 85% for daraxonrasib. The combination of elironrasib plus daraxonrasib showed encouraging preliminary antitumor activity in 26 patients with previously treated KRAS G12C non-small cell lung cancer, who had been previously treated with a KRAS G12C(OFF) inhibitor. Because dose optimization of the RAS(ON) inhibitor doublet is ongoing, we're sharing daraxonrasib at doses ranging from 100 mg to 200 mg. On the left, we're showing the elironrasib monotherapy data in patients who were previously treated with a KRAS G12C(OFF) inhibitor. Response rate and disease control rate for elironrasib monotherapy were 42% and 79%, respectively. On the right, for the combination of elironrasib and daraxonrasib, the response rate was 62% and the disease control rate was 92%, well above the activity seen in this population with elironrasib monotherapy. The majority of patients on the combination remained on treatment of the February 10, 2025 data cutoff date. Taking a step back and looking at our data driven lung cancer strategy, we believe we have a clear path to pursuing our ambition to change the standard care for patients with RAS mutant lung cancer, both in first-line metastatic and in earlier lines of treatment. We launched our initiative in non-small cell lung cancer with our registrational study for daraxonrasib monotherapy in previously treated patients with RAS mutant lung cancer. The emerging zoldonrasib data point to clear opportunities to continue evaluating zoldonrasib in patients with RAS G12D mutant non-small cell lung cancer as monotherapy and in combination. The three pairwise combinations of daraxonrasib plus pembrolizumab, elironrasib plus pembrolizumab and the RAS(ON) inhibitor doublet of elironrasib plus daraxonrasib all acceptable tolerability and encouraging antitumor activity and create options in the first-line treatment setting. For patients with tumors harboring RAS G12C, we plan to pursue a chemo therapy sparing RAS(ON) inhibitor doublet treatment, including the elironrasib plus daraxonrasib along with checkpoint inhibitor. For patients with non-G12C disease, we plan to develop daraxonrasib in combination with standard care chemotherapy along with checkpoint inhibitor. We believe each compound in our clinical stage RAS(ON) inhibitor portfolio has the potential to transform treatment for patients living with RAS mutant non-small cell lung cancer. With that, I'll turn the call over to Jack.