Atirmociclib

iStock, Marut Khobtakhob Pfizer showcased multiple late-breakers at the American Society of Clinical Oncology’s annual conference but its biggest data are expected later this year. Pfizer arrived in Chicago this weekend for the American Society of Clinical Oncology’s annual conference fresh off a $10.5 billion deal with China’s Innovent Biologics, as the company seeks to bolster its oncology pipeline. “It is not a big [ASCO] year from the vantage-point of stock-moving data,” Leerink Partners analyst David Risinger told BioSpace . “The focus is looking forward to the Pfizer readouts ahead.” Risinger noted that the company’s most anticipated updates from an investor standpoint are set for later this year. The New York pharma giant showcased data across more than 40 abstracts at ASCO 2026, plus three late-breakers and several oral presentations. All told, the data ranged from striking, long-term results for approved drugs to previews of what’s coming, including some assets out of China. “We want to go big and make impact,” Johanna Bendell, Pfizer’s chief development officer of oncology, told BioSpace prior to the conference. China Pfizer bets up to $10.5B in 12-candidate cancer collab with China’s Innovent Pfizer continues its dealmaking spree by striking a back-heavy partnership with China’s Innovent Biologics to assemble a pipeline of antibody-based therapies for cancer. May 29, 2026 · 2 min read · Tristan Manalac Read more Wins in lung, colorectal and prostate cancer In its late-breaking abstracts, Pfizer presented new data for drugs already in clinic, cementing them as strong treatment options or providing evidence for their use in earlier-stage disease. The company on Friday shared updated data from its Phase 3 CROWN trial , comparing ALK inhibitor Lobrena to its earlier-generation oral kinase inhibitor Xalkori in patients with previously untreated, ALK-positive advanced non-small cell lung cancer (NSCLC). At seven years, patients taking Lobrena saw an 81% drop in the risk of disease progression or death. These patients had a 55% likelihood of being alive without disease progression, compared to just 3% of those in the control arm. Overall survival (OS) data is not yet available, Bendell said. Pfizer is hoping to see this metric within the next year. “The durability of the benefit is unlike any trial we’ve seen,” Sarah Goldberg, chief of thoracic oncology at Yale Cancer Center, told BioSpace . “The CROWN data have looked good for a long time, but as we get longer-term follow-up, I think it’s more convincing that this should be our choice for first-line treatment.” Meanwhile, Bendell, who previously treated patients with gastrointestinal cancers, is particularly excited about new results from BREAKWATER . The trial evaluates Pfizer’s BRAF inhibitor Braftovi plus Eli Lilly’s Erbitux and the FOLFIRI chemotherapy regimen for previously untreated patients with BRAF V600E-mutant metastatic colorectal cancer, compared to FOLFIRI with or without bevacizumab. FOLFIRI and FOLFOX are common chemo regimens for patients with colorectal cancer, and earlier BREAKWATER data showed strong benefit for Braftovi plus Erbitux and mFOLFOX6. The FDA granted Braftovi full approval in first-line metastatic colorectal cancer in February. In this latest readout from BREAKWATER, the Braftovi/FOLFIRI combo also cut the risk of progression or death, this time by 56%, and PFS nearly doubled to 15.2 months versus 8.3 months in the comparator arm. Risk of death also declined by 44%, according to Pfizer’s Monday press release . “You can choose whichever of the chemotherapy backbones. You’re still going to have a significant impact by bringing Braftovi in for these patients,” Bendell said. Meanwhile, adding Pfizer’s PARP inhibitor Talzenna to the company’s Xtandi resulted in better outcomes for men with HHR-altered metastatic castration-sensitive prostate cancer, according to results from the Phase 3 TALAPRO-3 trial . The combination resulted in a 52% reduction in risk of radiographic progression or death, compared to placebo plus Xtandi. At three years, some 77% of patients on the combination still had radiographic PFS (rPFS), compared to 56% of those in the control arm. The results from TALAPRO-3 could move the combination earlier into the disease course, before castration resistance, Bendell said. “The earlier you move the therapy, the more impact that you can have for patients.” The results could help support the growth of Talzenna going forward, as Xtandi is soon set to face generic competition, Risinger said, adding that those were very important results. A look ahead—and a patent cliff Elsewhere at ASCO, Pfizer unveiled new data from assets designed to be the future of its oncology business. One such drug is the company’s CDK4 inhibitor atirmociclib, the heir apparent to its blockbuster breast cancer drug Ibrance, which loses patent protection next year. Breast cancer Pfizer’s Ibrance Heir Reduces Risk of Death in Phase 2 Breast Cancer Test Pfizer has a lofty goal for the CDK4 inhibitor atirmociclib, the New York pharma’s answer to Ibrance’s loss of patent protection next year. In 2025, Ibrance led Pfizer’s oncology portfolio with $1.04 billion in sales. March 17, 2026 · 1 min read · Annalee Armstrong Read more The Phase 2 FourLight-2 trial evaluated neoadjuvant atirmociclib plus letrozole vs. letrozole alone among 121 patients with HR+/HER2- breast cancer. Based on Ki-67 biomarker data, the proportion of patients taking atirmociclib who achieved complete cell cycle arrest at two weeks was 88.2% compared to 17.9% in the comparator group. Patients on atirmociclib also had more side effects, with nearly 20% experiencing diarrhea. The efficacy was compelling, but the gastrointestinal toxicity is a key question going forward, Risinger said . Pfizer also put up data in the competitive PD-1/VEGF bispecific antibody space, where Summit Therapeutics and its Chinese biopharma partner Akeso made headlines with their candidate ivonescimab. BioNTech and Bristol Myers Squibb also presented solid data for their asset pumitamig. Immuno-oncology ASCO: Summit reached with China lung data but new climb begins to prove global benefit “King Keytruda’s reign continues,” analysts at BMO Capital Markets declared after Chinese data for Summit Therapeutics’ ivonescimab were revealed at the American Society for Clinical Oncology in Chicago. June 1, 2026 · 3 min read · Annalee Armstrong Read more In updated results from a Phase 2 trial of Pfizer’s bispecific PD-1/VEGF antibody SSGJ-707 (PF’4404), the confirmed objective response rate was 75.0% for patients with squamous-cell NSCLC and 63.6% for non-squamous cell NSCLC, with a median PFS of 8.9 months and 12.4 months, respectively. “The data were encouraging, but the jury is still out with respect to which agents will differentiate,” Risinger said. The compound also showed promise in endometrial cancer in a different Phase 2 trial . Among 29 patients with advanced or recurrent endometrial cancer, the confirmed objective response rate was 85.7% at a 5-mg/kg dose and 80.0% at 10 mg/kg. Pfizer paid $1.25 billion upfront to license the bispecific from 3SBio in 2025, and the company has since launched 12 clinical trials in the program and plans to start five more. As for key upcoming data, Risinger pointed to several readouts, including one around the middle of this year for Pfizer’s investigational antibody-drug conjugate (ADC) sigvotatug vedotin (SV) versus docetaxel in second-line NSCLC. Last week, Pfizer amended the primary endpoint to OS only, with the change likely to mildly increase the chance of success, analysts at BMO Capital Markets wrote in a note to investors last Wednesday. PFS will now be a descriptive secondary endpoint, the firm noted. “While such a change reduces our confidence in the robustness of PFS, OS remains the highest importance in NSCLC, making this change rationale for increasing SV’s chances to demonstrate clinically meaningful results,” the analysts wrote. “SV is expected to be a blockbuster for NSCLC,” Risinger said. Also awaited in the second half of 2026 are results from the Phase 3 MEVPRO-1 trial , evaluating the EZH2 inhibitor mevrometostat plus enzalutamide in patients with previously treated metastatic castration-resistant prostate cancer. Plus, this upcoming weekend, Phase 2 data will be presented for Pfizer’s monthly, long-acting injectable GLP-1 that it acquired from Metsera at the 2026 American Diabetes Association ’s Scientific Sessions, as the company builds out its obesity assets. As Risinger said, “there’s a broad pipeline at Pfizer that is needed to offset the patent cliffs ahead.” .responsive-container { display: flex; flex-wrap: wrap; border: 1px solid #ededed; font-family: Helvetica, Arial, Sans-Serif; padding: 20px 20px 10px 20px; } .column-left { flex: 1; max-width: 45%; padding: 20px 20px 10px 20px; } .column-right { flex: 2; padding: 20px 20px 10px 20px; } @media (max-width: 768px) { .column-left, .column-right { max-width: 100%; flex: 100%; padding: 10px 0; } } Subscribe to ClinicaSpace! Clinical trial results, research news, the latest in cancer, cell and gene therapy hbspt.forms.create({ region: "na1", portalId: "4413123", formId: "674f4dc0-7371-4190-86cc-e1afd00b08ea", onFormSubmitted: function($form, data) { window.dataLayer = window.dataLayer || []; window.dataLayer.push({ 'event': 'GTMevent', 'event_name': 'newsletter_sign_up' }); } });