On September 12, 2022 Amgen (NASDAQ: AMGN) reported updated data from its Phase 1b CodeBreaK 101 study, one of the most comprehensive global clinical development programs in patients with KRAS G12C-mutated colorectal cancer (CRC) (Press release, Amgen, SEP 12, 2022, View Source [SID1234619406]). These data show that combining LUMAKRAS/LUMYKRAS (sotorasib) with Vectibix (panitumumab), Amgen’s monoclonal anti-epidermal growth factor receptor (anti-EGFR) antibody, demonstrated encouraging efficacy and safety. Overall, the confirmed objective response rate (ORR) was 30% in patients with chemo-refractory metastatic colorectal cancer (mCRC). These data were presented today during an oral session at the European Society for Medical Oncology (ESMO) (Free ESMO Whitepaper) Annual Meeting in Paris, France.

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"We are thrilled to see these CodeBreaK 101 results, which show that LUMAKRAS plus Vectibix achieved a 30% confirmed objective response rate in patients with KRAS G12C-mutated metastatic colorectal cancer. Treatment response rates can be as low as 2% in this patient population, and the current standard of care offers a median progression-free survival benefit of two months, so developing new treatment options is critically important for patients," said David M. Reese, M.D., executive vice president of Research and Development at Amgen. "These data are encouraging as we continue to focus on combination approaches in colorectal cancer, including advancing CodeBreaK 300, the Phase 3 LUMAKRAS plus Vectibix trial in the chemotherapy-refractory patient population."

In total, 40 patients with heavily pre-treated (median of two prior lines of therapy; range 1-7) KRAS G12C-mutated chemo-refractory mCRC were enrolled in the dose expansion cohort for the combination of LUMAKRAS and Vectibix. Disease control was seen in 37 patients for a total of 92.5% with a median progression free survival (PFS) of 5.7 months. There were no apparent differences found in the efficacy between left-sided and right-sided tumors. Tumor shrinkage of any magnitude was observed in 88% of patients, based on Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, and the median Duration of Treatment (DoT) was 5.9 months with 25% of patients remaining on treatment at the time of data cutoff. With a median follow up of 8.8 months, median overall survival (OS) was not yet reached. Treatment-related adverse events (TRAEs) reported with the combination were consistent with known safety profiles of the individual medicines, and no TRAEs resulted in discontinuation of either drug.

"These data are positive news for patients because they demonstrate encouraging efficacy and safety for sotorasib and panitumumab, as current treatments for chemo-refractory colorectal cancer provide limited survival benefits and can have notable safety issues," said Yasutoshi Kuboki, chief, Department of Experimental Therapeutics, National Cancer Center Hospital East, Japan. "There is a significant treatment gap for patients with KRAS G12C-mutated colorectal cancer and it is imperative that we continue to explore and develop precision therapies, like sotorasib, for these patients."

KRAS is a commonly mutated oncogene in CRC, with mutations in approximately 40% of all cases, with the KRAS G12C mutation present in approximately 3-5% of colorectal cancers. These patients face a dismal prognosis and have very limited treatment options.

*LUMAKRAS is marketed as LUMYKRAS (sotorasib) in the European Union, the United Kingdom and Switzerland.

About LUMAKRAS/LUMYKRAS (sotorasib)
Amgen took on one of the toughest challenges of the last 40 years in cancer research by developing LUMAKRAS/LUMYKRAS, a KRASG12C inhibitor.1 LUMAKRAS/LUMYKRAS has demonstrated a positive benefit-risk profile with rapid, deep, and durable anticancer activity in patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) harboring the KRAS G12C mutation with a once daily oral formulation.2

Amgen is progressing the largest and broadest global KRASG12C inhibitor development program with unparalleled speed and exploring more than 10 sotorasib combination regimens, with clinical trial sites spanning five continents. To date, over 6,500 patients around the world have received LUMAKRAS/LUMYKRAS through the clinical development program and commercial use.

In May 2021, LUMAKRAS was the first KRASG12C inhibitor to receive regulatory approval with its approval in the U.S., under accelerated approval. LUMAKRAS/LUMYKRAS is also approved in the European Union, Japan, United Arab Emirates, South Korea, Hong Kong, Switzerland, Taiwan, Qatar, and in Australia, Brazil, Canada, Great Britain, Singapore, and Israel under the FDA’s Project Orbis. Additionally, Amgen has submitted MAAs in Argentina, Colombia, Kuwait, Macao, Malaysia, Mexico, Russia, Saudi Arabia, Thailand and Turkey.

LUMAKRAS/LUMYKRAS is also being studied in multiple other solid tumors.3

About Advanced Colorectal Cancer and the KRAS G12C Mutation
Colorectal cancer (CRC) is the second leading cause of cancer deaths worldwide, comprising 10% of all cancer diagnoses.4 It is also the third most commonly diagnosed cancer globally.5

Patients with previously treated metastatic CRC need more effective treatment options. For patients in the third-line setting standard therapies yield median PFS times of about two months and patients’ response rates are less than 2%.6,7

KRAS mutations are among the most common genetic alterations in colorectal cancers, with the KRAS G12C mutation present in approximately 3-5% of colorectal cancers. 8,9,10

About CodeBreaK
The CodeBreaK clinical development program for Amgen’s drug sotorasib is designed to study patients with an advanced solid tumor with the KRAS G12C mutation and address the longstanding unmet medical need for these cancers.

CodeBreaK 100, the Phase 1 and 2, first-in-human, open-label multicenter study, enrolled patients with KRAS G12C-mutant solid tumors.11 Eligible patients must have received a prior line of systemic anticancer therapy, consistent with their tumor type and stage of disease. The primary endpoint for the Phase 2 study was centrally assessed objective response rate. The Phase 2 trial in NSCLC enrolled 126 patients, 124 of whom had centrally evaluable lesions by RECIST at baseline.2 The Phase 2 trial in colorectal cancer (CRC) is fully enrolled and results have been published.12

CodeBreaK 200, the global Phase 3 randomized active-controlled study comparing sotorasib to docetaxel in KRAS G12C-mutated NSCLC completed enrollment of 345 patients. Eligible patients had previously treated, locally advanced and unresectable or metastatic KRAS G12C-mutated NSCLC. The primary endpoint is progression-free survival and key secondary endpoints include overall survival, objective response rate, and patient-reported outcomes.13

Amgen also has several Phase 1b studies investigating sotorasib monotherapy and sotorasib combination therapy across various advanced solid tumors (CodeBreaK 101) open for enrollment.14 A Phase 2 randomized study will evaluate sotorasib in patients with stage IV KRAS G12C-mutated NSCLC in need of first-line treatment (CodeBreaK 201).15

For information, please visit www.hcp.codebreaktrials.com.

LUMAKRAS (sotorasib) U.S. Indication
LUMAKRAS is indicated for the treatment of adult patients with KRAS G12C-mutated locally advanced or metastatic non-small cell lung cancer (NSCLC), as determined by an FDA-approved test, who have received at least one prior systemic therapy.

This indication is approved under accelerated approval based on overall response rate (ORR) and duration of response (DOR). Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial(s).

LUMAKRAS (sotorasib) Important U.S. Safety Information
Hepatotoxicity
LUMAKRAS can cause hepatotoxicity, which may lead to drug-induced liver injury and hepatitis.
Among 357 patients who received LUMAKRAS in CodeBreaK 100, hepatotoxicity occurred in 1.7% (all grades) and 1.4% (Grade 3). A total of 18% of patients who received LUMAKRAS had increased alanine aminotransferase (ALT)/increased aspartate aminotransferase (AST); 6% were Grade 3 and 0.6% were Grade 4. In addition to dose interruption or reduction, 5% of patients received corticosteroids for the treatment of hepatotoxicity.
Monitor liver function tests (ALT, AST and total bilirubin) prior to the start of LUMAKRAS every 3 weeks for the first 3 months of treatment, then once a month or as clinically indicated, with more frequent testing in patients who develop transaminase and/or bilirubin elevations.
Withhold, dose reduce or permanently discontinue LUMAKRAS based on severity of adverse reaction.
Interstitial Lung Disease (ILD)/Pneumonitis
LUMAKRAS can cause ILD/pneumonitis that can be fatal. Among 357 patients who received LUMAKRAS in CodeBreaK 100, ILD/pneumonitis occurred in 0.8% of patients, all cases were Grade 3 or 4 at onset, and 1 case was fatal. LUMAKRAS was discontinued due to ILD/pneumonitis in 0.6% of patients.
Monitor patients for new or worsening pulmonary symptoms indicative of ILD/pneumonitis (e.g., dyspnea, cough, fever). Immediately withhold LUMAKRAS in patients with suspected ILD/pneumonitis and permanently discontinue LUMAKRAS if no other potential causes of ILD/pneumonitis are identified.
Most Common Adverse Reactions
The most common adverse reactions occurring in ≥ 20% were diarrhea, musculoskeletal pain, nausea, fatigue, hepatotoxicity and cough.
Drug Interactions
Advise patients to inform their healthcare provider of all concomitant medications, including prescription medicines, over-the-counter drugs, vitamins, dietary and herbal products.
Inform patients to avoid proton pump inhibitors and H2 receptor antagonists while taking LUMAKRAS.
If coadministration with an acid-reducing agent cannot be avoided, inform patients to take LUMAKRAS 4 hours before or 10 hours after a locally acting antacid.
Please see LUMAKRAS full Prescribing Information. 

About Vectibix (panitumumab)
Vectibix is the first fully human monoclonal anti-EGFR antibody approved by the FDA for the treatment of mCRC. Vectibix was approved in the U.S. in September 2006 as a monotherapy for the treatment of patients with EGFR-expressing mCRC after disease progression after prior treatment with fluoropyrimidine-, oxaliplatin-, and irinotecan-containing chemotherapy.

In May 2014, the FDA approved Vectibix for use in combination with FOLFOX, as first-line treatment in patients with wild-type KRAS (exon 2) mCRC. With this approval, Vectibix became the first-and-only biologic therapy indicated for use with FOLFOX, one of the most commonly used chemotherapy regimens, in the first-line treatment of mCRC for patients with wild-type KRAS mCRC.

In June 2017, the FDA approved a refined indication for Vectibix for use in in patients with wild-type RAS (defined as wild-type in both KRAS and NRAS as determined by an FDA-approved test for this use) mCRC.

INDICATION AND LIMITATION OF USE 
Vectibix is indicated for the treatment of patients with wild-type RAS (defined as wild-type in both KRAS and NRAS as determined by an FDA-approved test for this use) metastatic colorectal cancer (mCRC): as first-line therapy in combination with FOLFOX, and as monotherapy following disease progression after prior treatment with fluoropyrimidine-, oxaliplatin-, and irinotecan-containing chemotherapy.

Limitation of Use: Vectibix is not indicated for the treatment of patients with RAS mutant mCRC or for whom RAS mutation status is unknown.

IMPORTANT SAFETY INFORMATION
BOXED WARNING: DERMATOLOGIC TOXICITY
Dermatologic Toxicity: Dermatologic toxicities occurred in 90% of patients and were severe (NCI-CTC grade 3 and higher) in 15% of patients receiving Vectibix monotherapy [see Dosage and Administration (2.3), Warnings and Precautions (5.1), and Adverse Reactions (6.1)].

In Study 20020408, dermatologic toxicities occurred in 90% of patients and were severe (NCI-CTC grade 3 and higher) in 15% of patients with mCRC receiving Vectibix. The clinical manifestations included, but were not limited to, acneiform dermatitis, pruritus, erythema, rash, skin exfoliation, paronychia, dry skin, and skin fissures.
Monitor patients who develop dermatologic or soft tissue toxicities while receiving Vectibix for the development of inflammatory or infectious sequelae. Life-threatening and fatal infectious complications including necrotizing fasciitis, abscesses, and sepsis have been observed in patients treated with Vectibix. Life-threatening and fatal bullous mucocutaneous disease with blisters, erosions, and skin sloughing has also been observed in patients treated with Vectibix. It could not be determined whether these mucocutaneous adverse reactions were directly related to EGFR inhibition or to idiosyncratic immune- related effects (e.g., Stevens Johnson syndrome or toxic epidermal necrolysis). Withhold or discontinue Vectibix for dermatologic or soft tissue toxicity associated with severe or life-threatening inflammatory or infectious complications. Dose modifications for Vectibix concerning dermatologic toxicity are provided in the product labeling.
Vectibix is not indicated for the treatment of patients with colorectal cancer that harbor somatic RAS mutations in exon 2 (codons 12 and 13), exon 3 (codons 59 and 61), and exon 4 (codons 117 and 146) of either KRAS or NRAS and hereafter is referred to as "RAS."
Retrospective subset analyses across several randomized clinical trials were conducted to investigate the role of RAS mutations on the clinical effects of anti-EGFR-directed monoclonal antibodies (panitumumab or cetuximab). Anti-EGFR antibodies in patients with tumors containing RAS mutations resulted in exposing those patients to anti-EGFR related adverse reactions without clinical benefit from these agents. Additionally, in Study 20050203, 272 patients with RAS-mutant mCRC tumors received Vectibix in combination with FOLFOX and 276 patients received FOLFOX alone. In an exploratory subgroup analysis, OS was shorter (HR = 1.21, 95% CI: 1.01-1.45) in patients with RAS-mutant mCRC who received Vectibix and FOLFOX versus FOLFOX alone.
Progressively decreasing serum magnesium levels leading to severe (grade 3-4) hypomagnesemia occurred in up to 7% (in Study 20080763) of patients across clinical trials. Monitor patients for hypomagnesemia and hypocalcemia prior to initiating Vectibix treatment, periodically during Vectibix treatment, and for up to 8 weeks after the completion of treatment. Other electrolyte disturbances, including hypokalemia, have also been observed. Replete magnesium and other electrolytes as appropriate.
In Study 20020408, 4% of patients experienced infusion reactions and 1% of patients experienced severe infusion reactions (NCI-CTC grade 3-4). Infusion reactions, manifesting as fever, chills, dyspnea, bronchospasm, and hypotension, can occur following Vectibix administration. Fatal infusion reactions occurred in postmarketing experience. Terminate the infusion for severe infusion reactions.
Severe diarrhea and dehydration, leading to acute renal failure and other complications, have been observed in patients treated with Vectibix in combination with chemotherapy.
Fatal and nonfatal cases of interstitial lung disease (ILD) (1%) and pulmonary fibrosis have been observed in patients treated with Vectibix. Pulmonary fibrosis occurred in less than 1% (2/1467) of patients enrolled in clinical studies of Vectibix. In the event of acute onset or worsening of pulmonary symptoms interrupt Vectibix therapy. Discontinue Vectibix therapy if ILD is confirmed.
In patients with a history of interstitial pneumonitis or pulmonary fibrosis, or evidence of interstitial pneumonitis or pulmonary fibrosis, the benefits of therapy with Vectibix versus the risk of pulmonary complications must be carefully considered.
Exposure to sunlight can exacerbate dermatologic toxicity. Advise patients to wear sunscreen and hats and limit sun exposure while receiving Vectibix.
Keratitis and ulcerative keratitis, known risk factors for corneal perforation, have been reported with Vectibix use. Monitor for evidence of keratitis or ulcerative keratitis. Interrupt or discontinue Vectibix for acute or worsening keratitis.
In an interim analysis of an open-label, multicenter, randomized clinical trial in the first-line setting in patients with mCRC, the addition of Vectibix to the combination of bevacizumab and chemotherapy resulted in decreased OS and increased incidence of NCI-CTC grade 3-5 (87% vs 72%) adverse reactions. NCI-CTC grade 3-4 adverse reactions occurring at a higher rate in Vectibix-treated patients included rash/acneiform dermatitis (26% vs 1%), diarrhea (23% vs 12%), dehydration (16% vs 5%), primarily occurring in patients with diarrhea, hypokalemia (10% vs 4%), stomatitis/mucositis (4% vs < 1%), and hypomagnesemia (4% vs 0).
NCI-CTC grade 3-5 pulmonary embolism occurred at a higher rate in Vectibix-treated patients (7% vs 3%) and included fatal events in three (< 1%) Vectibix-treated patients. As a result of the toxicities experienced, patients randomized to Vectibix, bevacizumab, and chemotherapy received a lower mean relative dose intensity of each chemotherapeutic agent (oxaliplatin, irinotecan, bolus 5-FU, and/or infusional 5-FU) over the first 24 weeks on study compared with those randomized to bevacizumab and chemotherapy.
Vectibix can cause fetal harm when administered to a pregnant woman. Advise pregnant women and females of reproductive potential of the potential risk to a fetus. Advise females of reproductive potential to use effective contraception during treatment, and for at least 2 months after the last dose of Vectibix.
In monotherapy, the most commonly reported adverse reactions (≥ 20%) in patients with Vectibix were skin rash with variable presentations, paronychia, fatigue, nausea, and diarrhea.
The most commonly reported adverse reactions (≥ 20%) with Vectibix + FOLFOX were diarrhea, stomatitis, mucosal inflammation, asthenia, paronychia, anorexia, hypomagnesemia, hypokalemia, rash, acneiform dermatitis, pruritus, and dry skin. The most common serious adverse reactions (≥ 2% difference between treatment arms) were diarrhea and dehydration.