RMC-9805

Revolution Medicines' zoldonrasib (RMC-9805) is an oral, covalent, mutant-selective KRAS G12D(ON) inhibitor - a first-in-class small molecule that grabs the active 'on' form of mutated KRAS and shuts it down [1]. KRAS G12D is the single most common oncogenic mutation in pancreatic cancer, accounting for roughly 40% of cases, and shows up in meaningful slices of colorectal and lung cancers, so the addressable patient population dwarfs the G12C niche that Amgen's sotorasib and Mirati/Bristol Myers Squibb's adagrasib opened up. The drug has advanced into Phase 3 with RASolute 305 (NCT07621718), a randomized trial against investigator's-choice chemotherapy in first-line metastatic G12D-mutant pancreatic adenocarcinoma, while a Phase 1/2 monotherapy study (NCT06040541) continues to recruit across G12D-mutant solid tumors [2][1]. The Phase 1 PDAC expansion data presented at ASCO GI 2025 showed a 30% confirmed-or-pending ORR and 80% disease control rate at 1200 mg QD or 600 mg BID, with 86% of evaluable patients showing >50% ctDNA reduction and 39% achieving complete ctDNA clearance [11]. FDA granted Breakthrough Therapy Designation for zoldonrasib in previously treated KRAS G12D-mutant NSCLC in 2026 [12]. Revenue data not available - zoldonrasib is investigational. Revolution Medicines (RVMD) is a pure-play RAS franchise built around this drug and the pan-RAS(ON) agent daraxonrasib (RMC-6236).

Zoldonrasib is a novel compound. No drug targeting KRAS G12D has been approved in any indication. The lead Phase 3 trial RASolute 305 (NCT07621718) is recruiting against an enrollment target of 670 patients, comparing zoldonrasib monotherapy (1200 mg QD oral) to investigator's-choice chemotherapy in first-line metastatic KRAS G12D-mutant pancreatic ductal adenocarcinoma, with progression-free survival as the primary endpoint and overall survival as a key secondary endpoint [2]. The Phase 1/2 monotherapy study (NCT06040541) is enrolling 604 patients across G12D-mutant solid tumors and is the source of the dose-finding and early efficacy data that supported the Phase 3 commitment, including the ASCO GI 2025 PDAC expansion readout [1][11]. Zoldonrasib also appears in Revolution Medicines' RAS(ON) basket protocols across GI tumors (NCT06445062, n=1,130) and RAS-mutant NSCLC (NCT06162221, n=616), and in a Tango Therapeutics-sponsored combination with TNG462 (NCT06922591) [3][4][5]. FDA granted Breakthrough Therapy Designation in previously treated KRAS G12D-mutant NSCLC in 2026; orphan drug designation for PDAC has not been publicly confirmed [12]. Revolution Medicines has used a string of 2025-2026 8-K filings to disclose program updates, including the RASolute 305 launch [6].

KRAS is a protein that acts like an on/off switch for cell growth. In its normal state it flips on briefly when growth signals arrive, then turns itself off. The G12D mutation, a single amino-acid swap from glycine to aspartate, breaks the off switch - so KRAS stays in the 'on' position and the cell keeps dividing. About 40% of pancreatic cancers, 13% of colorectal cancers, and 4% of non-small cell lung cancers carry this exact mutation, which makes KRAS G12D the largest oncogenic driver in human cancer by total patient count [7]. For 40 years the field treated KRAS as undruggable because the active 'on' form has no obvious pocket for a small molecule to bind. Revolution Medicines' approach borrows what they call the 'RAS(ON)' tri-complex strategy: the drug recruits cyclophilin A, a common cellular chaperone, and uses it to wedge against the active KRAS surface, locking the mutant protein into a non-functional complex. Zoldonrasib forms a covalent bond to the mutant aspartate residue itself, which gives it selectivity for G12D over wild-type KRAS, important because wild-type KRAS is essential for normal tissue. The validation case is solid: approved KRAS G12C inhibitors (sotorasib, adagrasib) proved the broader RAS-locked approach works in patients [8], and Mirati/BMS's MRTX1133 showed preclinical proof that G12D-selective inhibition produces tumor regression [9].

RASolute 305 (NCT07621718) is the lead Phase 3: a randomized study of zoldonrasib monotherapy (1200 mg oral once daily, the dose selected from the Phase 1 expansion) versus investigator's-choice chemotherapy - gemcitabine/nab-paclitaxel or FOLFIRINOX - as first-line treatment in metastatic KRAS G12D-mutant pancreatic adenocarcinoma. Primary endpoint is progression-free survival; overall survival is a key secondary endpoint, which matters because PDAC regulators have historically required OS evidence and a PFS-only label is not assured [2]. Target enrollment 670 patients across global sites. The design is reasonable for the setting. Median PFS in 1L PDAC sits around 5.5-6 months on standard chemo, so a clean hazard ratio against an active comparator gives a defined regulatory path. The strategic question is whether single-agent G12D inhibition can outperform combination chemotherapy in 1L. Most precision oncology agents in PDAC have moved to combination first; Revolution Medicines is betting the biomarker-selected signal is strong enough to win as monotherapy. The parallel Phase 1/2 monotherapy study (NCT06040541) enrolling 604 patients provides dose-expansion efficacy data that contextualize the Phase 3 readout, particularly ORR and duration of response in the 1L PDAC expansion cohort - the most recent disclosure was 30% ORR and 80% DCR at ASCO GI 2025 [1][11]. The Tango-sponsored TNG462 combination study (NCT06922591) is a separate combo-PRMT5 program and not the primary efficacy readout for zoldonrasib [5].

Our model estimates a 40% chance this drug is eventually approved. It starts from the historical base rate for Phase 3 drugs in this area (about 48%), then adjusts using ten facts about the trial and sponsor. What moves the number most: it is helped by a non-randomized design and an unusually multi-arm design (8 arms); it is held back by the sponsor's thin or weak approval record and weak or limited earlier-phase results. The other facts land near average for this stage, so they leave the estimate roughly where the base rate put it.

Efficacy risk is the biggest one. PDAC has crushed nearly every targeted-therapy and novel-agent bet of the last decade - erlotinib+gemcitabine cleared FDA but produced <2 weeks OS benefit, masitinib failed Phase 3, and ERYTECH's eryaspase missed its Phase 3 primary endpoint in 2022. Monotherapy zoldonrasib must beat a moving chemo benchmark, and KRAS G12D inhibition in PDAC may face adaptive resistance through RTK reactivation, MAPK pathway rewiring, or wild-type RAS isoform compensation - the same resistance patterns that cap G12C inhibitor durability in NSCLC. Safety: on-target wild-type KRAS inhibition would drive GI and skin toxicity similar to MEK or EGFR inhibitors. Zoldonrasib's mutant-selective design should mitigate this, and the Phase 1 safety profile is consistent with that thesis - predominantly low-grade nausea (27%), diarrhea (20%), vomiting (15%), and rash (10%) - but covalent inhibitors carry idiosyncratic hepatic and immune risks, and long-term tolerability across many months of dosing remains unproven [11]. Execution: the Phase 3 requires 670 patients in a biomarker-defined population where G12D testing is not routine at all centers. Screen failure rates and site activation pace will set timeline. Commercial: even with approval, payers will price-anchor to gem/nab-pac and FOLFIRINOX; meaningful OS benefit is needed to justify premium pricing. Financing: Revolution Medicines ended Q1 2026 with approximately $4.0B in cash following a $2.1B April 2026 raise, with company guidance indicating multi-year runway through RASolute readouts - financing risk for the Phase 3 program is low [13]. Competitive: Astellas/Astex's ASTX295, Hengrui's HRS-4642, and Verastem/GenFleet's VS-7375 are all working the same target. If a competitor lands first with a better tolerability or durability profile, the commercial window narrows fast.

Worth watching closely. KRAS G12D is the largest unaddressed oncogenic driver by patient count, and zoldonrasib is the most clinically advanced selective G12D drug in development. The Phase 1 PDAC expansion data - 30% ORR, 80% DCR, 86% ctDNA reduction in evaluable patients [11] - clears the threshold that supported the Phase 3 commitment and is roughly comparable to what sotorasib delivered in G12C NSCLC (ORR ~37%, mPFS ~6.8 months in CodeBreaK 100). FDA Breakthrough Therapy Designation in KRAS G12D NSCLC adds regulatory tailwind [12]. The next signals that matter: Phase 1/2 PDAC and NSCLC expansion updates at ASCO GI January 2027 and ASCO 2027, and the RASolute 305 PFS readout estimated H2 2027 - 2028 pending enrollment completion (Phase 3 trials in PDAC typically read out 12-18 months after last patient enrolled). If those numbers hold or improve, Revolution Medicines has a real shot at the PDAC indication and a credible follow-on path into 1L colorectal. If responses shorten or OS does not separate, the monotherapy bet weakens and combination strategies will dominate. With ~$4.0B cash and runway through RASolute readouts [13], the company can execute without dilutive pressure. Revolution Medicines also runs daraxonrasib (RMC-6236, pan-RAS(ON)) in parallel - RASolute 302 plenary readout at ASCO 2026 is the proximal franchise catalyst - so the company's RAS readthrough extends beyond zoldonrasib alone, but G12D is the single most valuable individual asset given its market size.