A roundup of the latest drug approvals, including from the pharmaceutical majors, featuring news from Pfizer, AstraZeneca, and Merck & Co.

Editor’s Note: This article was updated on a continuous basis for news announced from Wednesday August 16, 2017 to Tuesday August 22, 2017.

FDA Approves Pfizer’s ADC Leukemia Drug
The US Food and Drug Administration (FDA) has approved Pfizer’s Besponsa (inotuzumab ozogamicin), an antibody drug conjugate (ADC), for treating adults with relapsed or refractory B-cell precursor acute lymphoblastic leukemia (ALL).

Besponsa is composed of a monoclonal antibody targeting CD22, a cell-surface antigen expressed on cancer cells in almost all B-ALL patients, according to Pfizer, linked to a cytotoxic agent. When Besponsa binds to the CD22 antigen on B-cells, it is internalized into the cell, where the cytotoxic agent calicheamicin is released causing cell death, according to Pfizer.

Besponsa was reviewed and approved under the FDA’s breakthrough therapy designation and priority review programs.

Besponsa is one of two ADCs by Pfizer under recent regulatory review. In July 2017, the FDA’s Oncologic Drug Advisory Committee recommended for approval Pfizer’s ADC, Mylotarg (gemtuzumab ozogamicin), for treating acute myeloid leukemia (AML).

Mylotarg is an investigational ADC comprised of the cytotoxic agent calicheamicin, attached to a monoclonal antibody targeting CD33, an antigen expressed on the surface of myeloblasts in more than 90% of AML patients, according to Pfizer. When Mylotarg binds to the CD33 antigen on the cell surface, it is absorbed into the cell, and calicheamicin is released causing cell death, according to Pfizer.

Mylotarg was originally approved by the FDA in 2000 under an accelerated approval program for use as a single agent in first relapse patients with CD33-positive AML who were 60 years or older. In 2010, Pfizer voluntarily withdrew Mylotarg after a confirmatory Phase III trial at that time did not show a clinical benefit, and the fatal induction toxicity rate was significantly higher in the Mylotarg arm of the clinical trial.

Mylotarg and Besponsa originate from a collaboration between Pfizer and Celltech, now UCB. Pfizer has sole responsibility for all manufacturing and clinical development activities for Besponsa.

Currently, there are only two ADCs approved on the market, Seattle Genetics’/Takeda Pharmaceuticals’ Adcetris (brentuximab vedotin), indicated for treating classical Hodgkin lymphoma and systemic anaplastic large cell lymphoma, and Roche’s Kadcyla (trastuzumab emtansine), indicated for treating HER2-positive, metastatic breast cancer.

Source: Pfizer

AstraZeneca, Merck & Co. Get Additional Use for Cancer Drug Lynparza
The US Food and Drug Administration (FDA) has granted additional approvals for AstraZeneca’s and Merck & Co.’s cancer drug, Lynparza (olaparib), an oral poly ADP-ribose polymerase (PARP) inhibitor.

The FDA has granted a new use of Lynparza as a maintenance treatment for recurrent, epithelial ovarian, fallopian tube, or primary peritoneal adult cancer who are in response to platinum-based chemotherapy, regardless of BRCA status. Another new use of Lynparza tablets includes (2 tablets twice daily) as opposed to capsules (8 capsules twice daily).

Lynparza tablets are also indicated in treating patients with deleterious or suspected deleterious germline BRCA-mutated advanced ovarian cancer, who have been treated with three or more prior lines of chemotherapy.

It is approved by regulatory authorities in the European Union and US for treating women with BRCA-mutated ovarian cancer. Lynparza tablets are currently being tested in combinations in a range of tumor types including breast, prostate, and pancreatic cancers.

In July 2017, AstraZeneca and Merck & Co., entered into a global strategic oncology collaboration to co-develop and co-commercialize AstraZeneca’s Lynparza for multiple cancer types. The companies are jointly developing Lynparza and selumetinib, the active ingredient in another AstraZeneca’s cancer drug, in combination with other potential new medicines and as a monotherapy. Independently, the companies will develop Lynparza and selumetinib in combination with their respective PD-L1 and PD-1 medicines.

Source: Merck & Co. and AstraZeneca