Conference Coverage

Getting hematologic cancer drugs on the fast track


 

EXPERT ANALYSIS FROM TCLF 2018

– The words “rapid approval” and “Food and Drug Administration” rarely appear in the same sentence. But despite that perception, the pace of hematologic drug development has been accelerating over the last several years, according to an agency staffer.

“FDA is committed toward the expedited development of safe and effective therapies for serious and life-threatening diseases,” R. Angelo de Claro, MD, of the FDA’s Office of Hematology and Oncology Products said at the annual T-cell Lymphoma Forum. Dr. de Claro outlined his agency’s efforts to accelerate approval of drugs for treatment of T-cell malignancies.

Hematologic drug bonanza

In 2017 alone, the FDA approved 17 agents for new or expanded indications for hematologic malignancies, including brentuximab vedotin (Adcetris) for anaplastic large cell lymphoma (ALCL) and CD30-positive mycosis fungoides (MF).

Approval was based on a 56% objective response rate for brentuximab vedotin versus 12% for physician’s choice in a phase 3 trial (ALCANZA) of 131 patients with mycosis fungoides or primary cutaneous ALCL. All patients had received one prior systemic therapy and were randomized (1:1) to receive either brentuximab vedotin or the physician’s choice of methotrexate or bexarotene.

Dr. de Claro noted that in the ALCANZA trial, patients were required to have one or more biopsy samples with at least 10% CD30 expression, but among 184 patients with MF screened for the trial, 32% were ineligible because of less than 10% CD30 expression. The FDA therefore requested additional efficacy data for patients with MF with less than 10% CD30 expression and accepted data from two investigator-sponsored trials showing that 35 patients with MF expressing CD30 on 1%-9% of cells had a 31% overall response rate, whereas two patients with no CD30 expression did not have responses.

Who minds the store

Hematology products are under the aegis of the FDA’s Oncology Center of Excellence. Oversight includes benign hematology products, as well as products for hematologic cancers and hematologic support. Hematology and oncology toxicology is monitored by pharmacologists and toxicologists in a separate division, he explained.

“The Oncology Center of Excellence was formally launched in 2017 as part of the 21st century CURES Act. The mission of the Oncology Center of Excellence is to achieve patient-centered regulatory decision making through innovation and collaboration,” he said.

Getting the nod

To get approved, a new therapy requires “substantial” evidence of efficacy and safety. Regular approvals are based on either direct measures of clinical benefits – how a patient “feels, functions, or survives” – or a measure of the effect of a drug on an established surrogate endpoint.

For an accelerated approval, developers must be able to show evidence on either a surrogate or intermediate clinical endpoint that the agent is reasonably likely to offer a benefit and be a meaningful improvement over available therapies. Postapproval trials may be needed to verify the proposed benefits.

FDA accelerated approval programs include:

  • Fast track. The pathway requires nonclinical or clinical data demonstrating the potential for addressing an unmet need.
  • Breakthrough therapy. This pathway requires preliminary clinical evidence demonstrating substantial improvement over existing available therapies.
  • Priority review. These are agents that, if approved, would provide significant improvements in safety or effectiveness.
  • Accelerated approval. The drug must demonstrate an effect on an “endpoint reasonably likely to predict clinical benefit over available therapies.”

Dr. de Claro is employed by the FDA. The T-Cell Lymphoma Forum is held by Jonathan Wood & Associates, which is owned by the same company as this news organization.

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