The US Food and Drug Administration's Oncologic Drugs Advisory Committee (ODAC) has delivered significant setbacks to two major pharmaceutical companies, voting against new indications for cancer treatments from both Genentech and Pfizer.
In the first decision, the committee voted 8-1 against recommending approval for a new indication of Genentech's Columvi (glofitamab). The panel expressed concerns about whether the pivotal trial data could be appropriately applied to the US patient population. The specific details of the proposed indication were not fully disclosed, but the overwhelming negative vote suggests substantial issues with the trial design or results.
Columvi, a CD20xCD3 bispecific antibody, was previously granted accelerated approval by the FDA in June 2023 for relapsed or refractory diffuse large B-cell lymphoma after two or more lines of systemic therapy. This current rejection represents a significant obstacle to Genentech's efforts to expand the drug's approved uses.
Unanimous Rejection for Pfizer's Combination Therapy
In a separate but equally decisive vote, the same advisory committee unanimously rejected Pfizer's application for Talzenna (talazoparib) in combination with Xtandi (enzalutamide) as a first-line treatment for adults with metastatic castration-resistant prostate cancer (mCRPC). The 8-0 vote against approval indicates serious concerns about the efficacy or safety profile of this combination therapy.
Talzenna is a PARP inhibitor currently approved for certain BRCA-mutated breast cancers, while Xtandi is an androgen receptor inhibitor widely used in prostate cancer treatment. The combination was being evaluated as a potential advancement in the treatment paradigm for prostate cancer patients who have limited options after developing resistance to initial hormone therapy.
Implications for Clinical Trial Design and Regulatory Strategy
These rejections highlight the FDA's increasing scrutiny of oncology drug applications, particularly regarding the applicability of clinical trial data to diverse patient populations. The specific concern about Genentech's trial not being applicable to US patients raises questions about international trial designs and the importance of ensuring appropriate demographic representation.
Dr. Richard Pazdur, director of the FDA's Oncology Center of Excellence, has previously emphasized the importance of trial populations that reflect the diversity of patients who will ultimately use the medications in clinical practice.
"These votes reflect our commitment to ensuring that approved cancer therapies demonstrate clear benefits for the specific patient populations they aim to treat," said one committee member who requested anonymity due to the sensitive nature of the deliberations.
Next Steps for the Companies
While advisory committee recommendations are not binding, the FDA typically follows their guidance, especially when votes are so decisive. Both Genentech and Pfizer now face difficult decisions about their regulatory strategies.
Options for the companies include conducting additional clinical trials with revised designs, submitting additional analyses of existing data, or potentially narrowing their proposed indications to more specific patient populations where the benefit-risk profile might be more favorable.
Industry analysts suggest these setbacks could delay potential approvals by years and significantly impact the commercial prospects for these therapies in their proposed new indications.
Market and Patient Impact
For patients with difficult-to-treat cancers who might have benefited from these therapies, these rejections mean continued reliance on existing treatment options. Particularly in advanced prostate cancer, where new treatment approaches are urgently needed, the unanimous rejection of the Talzenna-Xtandi combination represents a disappointment for the clinical community.
The FDA is expected to make final decisions on both applications in the coming months, taking into consideration the advisory committee's recommendations along with all available data.
