NEW YORK - The US Food and Drug Administration (FDA) on Monday granted accelerated approval to Pfizer’s therapy for treating patients with a type of blood cancer that is difficult to treat, the company said.

The health regulator’s decision allows use of the therapy, branded as Elrexfio, in patients with multiple myeloma that is hard to treat or has come back after receiving four or more prior lines of certain classes of treatments.

Elrexfio, or elranatamab, is administered under the skin and belongs to a class of therapies known as bispecific antibodies, which help the body’s immune system kill cancerous cells by bringing a cancer cell and an immune cell together.

Elrexfio will be sold in the United States at a list price of US$7,556 (S$10,300) and US$13,051 for the 44mg and the 76mg vial respectively, Pfizer said.

The list price of the therapy is expected to be US$41,500 a month, the company said, adding that it expects the monthly price to be lower at about US$26,000 as patients move to bi-weekly dosing.

Pfizer has said the therapy could have more than US$4 billion in potential peak revenue.

Elrexfio’s average treatment duration was eight months in the mid-stage trial, and the company expects the therapy will be available in the weeks following approval.

Multiple myeloma is a common type of blood cancer, which develops in the bone marrow and can spread throughout the body.

Several patients see a relapse after stopping treatment, making it an area of unmet need that drugmakers can tap into.

Other similar antibody therapies in the market include Roche’s Columvi, Abbvie’s Epkinly and Johnson & Johnson’s Talvey, which was approved last week.

Elrexfio can be used “off the shelf” and can be delivered on an ongoing basis by healthcare providers in hospitals and clinics, the company said on Monday.

The FDA approval is based on data from a mid-stage study that showed that 58 per cent of patients treated with Pfizer’s therapy had no signs of cancer or had seen a significant decrease in cancer cells in the body.

Pfizer said it will continue testing the therapy in ongoing late-stage trials to expand its use in earlier lines of treatment for patients.

The therapy’s approval comes with a boxed warning for neurologic toxicity and cytokine release syndrome, a condition where the immune system reacts more aggressively. REUTERS