Troubled Immunomedics now hit with CRL for breast cancer drug candidate

The troubles for troubled Immunomedics keep piling up. The New Jersey-based biotech, which has gone through a failed tie-up deal, boardroom cleansing and FDA Form 483 issues, today reported it has received a complete response letter from the FDA related to manufacturing concerns around its antibody-drug conjugate for breast cancer.

The company emphasized that the CRL was tied to Chemistry, Manufacturing and Control issues and would not require new clinical data. Immunomedics is seeking accelerated approval of sacituzumab govitecan as a third line treatment of patients with metastatic triple-negative breast cancer.  

"The issues related to approvability in the CRL were exclusively focused on Chemistry, Manufacturing and Control matters and no new clinical or preclinical data need to be generated," CEO Michael Pehl said in a statement. "We are going to request a meeting with the FDA as soon as possible to gain a full understanding of the agency’s requirements and timelines for approval and we will work closely with the FDA with the goal of bringing this important medicine to patients as soon as possible."

In a conference call, execs kept repeating those claims and shed little other light on the matter, evading questions on whether the issues stemmed from a Form 483 issued to the drugmaker during a preapproval inspection in August or even if they were tied to the company’s manufacturing site in Morris Plains, New Jersey.

Pehl called the CRL "unexpected," saying execs believe all issues are addressable for the breakthrough cancer treatment but refused to provide any details about specifics until they meet with the FDA.

It was just another in a string of upsets at the company. In May 2017, Seattle Genetics terminated a potential $2 billion development and licensing deal for sacituzumab govitecan after a shareholder revolt over the value of the deal. The fight led to the ouster of the company’s CEO Cynthia Sullivan and founder David Goldenberg.

The company responded by hiring biotech veteran Michael Pehl—formerly of Celgene—as its CEO, who in turn brought on several former Celgene colleagues for key roles.

But last month FDANews reported the FDA had issued a Form 483 for the company’s New Jersey facility during an inspection in August. It included a host of issues including "manipulated bioburden samples, misrepresentation of an integrity test procedure in the batch record, and backdating of batch records, such as dates of analytical results," FDANews reported. These are all serious concerns to the FDA.

Sacituzumab govitecan is an antibody-drug conjugate of SN-38—the active metabolite of the chemotherapy drug irinotecan—and Immunomedics’ anti-TROP2 asset hRS7. The ADC is designed to target the TROP-2 receptors that are found in certain tumors and hustle the payload into cells.

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