G1 Therapeutics’ Drug Reduces Chemo Related Side Effects, Nabs FDA OK

Chemotherapy is effective at killing cancer cells, but it comes at a price. Most of the chemotherapies are accompanied by well-known side effects that can weigh down the drug’s effect. G1 Therapeutics aims to change that with its CDK4/6 inhibitor, trilaciclib (Cosela), that got FDA’s OK on February 12th. This approval comes after the drug snagged a breakthrough designation in 2019.

“The most serious and life-threatening side effect of chemotherapy is myelosuppression, or damage to the bone marrow, resulting in reduced white blood cells, red blood cells, and platelets. This may lead to increased risk of infection, severe anemia, and/or bleeding,” Jeffery Crawford, Geller Professor for Research in Cancer in the Department of Medicine and Duke Cancer Institute, said in a statement.

Patients suffering from these side effects may be vulnerable to infections and, in severe cases, may need to be taken off the therapy. This delays the treatment and increases the burden on healthcare services that get consumed in controlling the side effects.

Now, Trilaciclib can help these patients as it becomes the first therapy to gain FDA approval that offers proactive “multilineage protection” from myelosuppressive side effects of the chemotherapy. The drug is currently approved for administration in extensive-stage small-cell lung cancer patients prior to platinum/etoposide or topotecan containing chemotherapies. This approval is welcome news for many patients who have to leave chemotherapy for fear of succumbing to side effects.

This drug is a proactive treatment and not a rescue treatment. The difference is that the rescue drug controls the side effects after chemotherapy, and the proactive drug protects from the possible occurrence of side effects during chemo treatment before chemo is administered. According to the company statement, “the drug is given intravenously as a 30-minute infusion within four hours ahead of the start of chemotherapy.”

Phase 2 Data

The approval of trilaciclib is based on three randomized placebo-controlled Phase 2 trials that showed “meaningful and statistically significant reduction in” the severity and duration of neutropenia- a condition that leads to a reduction in the count of neutrophils, a type of white blood cells.

Half of the people who receive chemotherapy have some level of neutropenia. Compared to placebo, administration of trilaciclib reduced the mean duration of severe neutropenia from 4 days to 0 days and occurrence of SN from almost 50% to 2%. The drug also demonstrated a positive impact on red blood cell transfusions and other myeloprotective measures. The drug’s protective effects were evaluated in combination with carboplatin/etoposide with or without atezolizumab immunotherapy and topotecan chemotherapy regimens.

Although trilaciclib treatment prevented chemotherapy-associated side effects, it brought about its own side effects, which commonly included fatigue, hypocalcemia, hypokalemia, hypophosphatemia, increased aspartate aminotransferase, headache and pneumonia. Serious adverse events occurred in 30% of patients, which included respiratory failure, hemorrhage, and thrombosis.

G1’s Future Plans

G1 started laying out the marketing plans for its drug when it snagged priority review from the FDA. The company inked a co-promotion deal last year in June with Boehringer Ingelheim to market the drug in the US and Puerto Rico as a treatment for small cell lung cancer and simultaneously made a pact with Simcere Pharma to promote and market the drug in Greater China, which includes China, Hong Kong, Macau, and Taiwan. The drug is expected to generate $500 million to $1 billion in revenues per year, considering it treats all 69,000 patients worldwide annually.

Besides lung cancer, the biotech is working on other indications, including colorectal cancer. It is expected to initiate a Phase3 trial in about 300 patients soon, which would produce data in 2023. Meanwhile, G1 will conduct post-approval rituals as any breakthrough-designated products commonly perform.

“G1 will conduct certain post-marketing activities, including in vitro drug-drug interaction and metabolism studies, and a clinical trial to assess the impact of trilaciclib on disease progression or survival in patients with ES-SCLC with chemotherapy-induced myelosuppression treated with a platinum/etoposide-containing or topotecan-containing regimen with at least a two year follow up.”

Related Article: FDA Approval of Tepotinib Sets Stage for Merck Versus Novartis Showdown in Metastatic NSCLC Space

References

1. http://investor.g1therapeutics.com/news-releases/news-release-details/fda-approves-g1-therapeutics-coselatm-trilaciclib-first-and-only

Author

Ruchi Jhonsa