A randomized phase II study of the MEK1/MEK2 inhibitor trametinib (GSK1120212) compared with docetaxel in KRAS-mutant advanced non-small-cell lung cancer (NSCLC)†

BACKGROUND

KRAS mutations are detected in 25% of non-small-cell lung cancer (NSCLC) and no targeted therapies are approved for this subset population. Trametinib, a selective allosteric inhibitor of MEK1/MEK2, demonstrated preclinical and clinical activity in KRAS-mutant NSCLC. We report a phase II trial comparing trametinib with docetaxel in patients with advanced KRAS-mutant NSCLC.

PATIENTS AND METHODS

Eligible patients with histologically confirmed KRAS-mutant NSCLC previously treated with one prior platinum-based chemotherapy were randomly assigned in a ratio of 2 : 1 to trametinib (2 mg orally once daily) or docetaxel (75 mg/m(2) i.v. every 3 weeks). Crossover to the other arm after disease progression was allowed. Primary end point was progression-free survival (PFS). The study was prematurely terminated after the interim analysis of 92 PFS events, which showed the comparison of trametinib versus docetaxel for PFS crossed the futility boundary.

RESULTS

One hundred and twenty-nine patients with KRAS-mutant NSCLC were randomized; of which, 86 patients received trametinib and 43 received docetaxel. Median PFS was 12 weeks in the trametinib arm and 11 weeks in the docetaxel arm (hazard ratio [HR] 1.14; 95% CI 0.75-1.75; P = 0.5197). Median overall survival, while the data are immature, was 8 months in the trametinib arm and was not reached in the docetaxel arm (HR 0.97; 95% CI 0.52-1.83; P = 0.934). There were 10 (12%) partial responses (PRs) in the trametinib arm and 5 (12%) PRs in the docetaxel arm (P = 1.0000). The most frequent adverse events (AEs) in ≥20% of trametinib patients were rash, diarrhea, nausea, vomiting, and fatigue. The most frequent grade 3 treatment-related AEs in the trametinib arm were hypertension, rash, diarrhea, and asthenia.

CONCLUSION

Trametinib showed similar PFS and a response rate as docetaxel in patients with previously treated KRAS-mutant-positive NSCLC.

CLINICALTRIALSGOV REGISTRATION NUMBER

NCT01362296.

Abstract PD10-05: HLA-DQA1*02:01/DRB1*07:01 as a biomarker for lapatinib-induced hepatotoxicity: prospective confirmation in a large randomised clinical trial (TEACH, EGF105485)

Hepatotoxicity is associated with small molecule tyrosine kinase inhibitors (TKI) in use for the treatment of a variety of cancers. Retrospective studies have identified and confirmed that specific Class II Human Leukocyte Antigen (HLA) alleles are strongly associated with ALT elevation in women treated with the TKI lapatinib for breast cancer. This study aimed to further evaluate and validate the role of the specified HLA alleles as predictors of elevated ALT in a pre-defined analysis of a large, randomized, double-blind, placebo-controlled study of lapatinib monotherapy in early stage HER2 positive breast cancer, the TEACH study (Tykerb Evaluation After Chemotherapy, EGF105485).

This prospectively defined pharmacogenetic study compared the frequency of hepatobiliary adverse events between pre-specified Major Histocompatibility Complex (MHC) genetic variants, including the HLA alleles DQA1*02:01 and DRB1*07:01. The primary focus was on elevated ALT, as well as rare cases of concurrent ALT (>3x ULN) and bilirubin (>2x ULN) elevation, which represent possible Hy's Law cases and a high risk of acute liver failure, among 1194 patients randomized to lapatinib treatment from whom pharmacogenetic data was available.

This study prospectively validated prior reports of the association of the specified MHC variants with elevated ALT among women treated with lapatinib. The strongest effects were observed for carriers of the HLA alleles DQA1*02:01 and DRB1*07:01, with odds ratios of 20 (95% CI: 8–40) between cases (n = 34) and controls (n = 807–808). These two HLA alleles are highly correlated, inherited together in most individuals and are consistent with a single genetic association. The overall risk of patients having an ALT (>3xULN) elevation was 3.0% and 0.7% during treatment with lapatinib and placebo respectively. Carriers of either HLA allele had a 12% chance (positive predictive value) of having an elevated ALT (>3xULN), in contrast to a 0.9% risk (negative predictive value, 99.1%) for non-carriers of the specified HLA alleles. These associations were maintained for higher ALT elevation thresholds and for cases of concurrent ALT and TBL elevation, consistent with possible Hy's Law cases. These results strongly support the role of Class II HLA-modulated immune mechanisms in lapatinib-induced hepatotoxicity.

Our results validate the large strength of association of the HLA alleles DRB1*07:01 and DQA1*02:01 with hepatotoxicity and provide the possibility of managing the risk of hepatotoxicity in women receiving lapatinib for early or late stage HER2 positive breast cancer. This association with immune mechanisms may have implications for toxicities with other TKIs in current use in cancer patients.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr PD10-05.

Hepatobiliary abnormalities in patients with metastatic cancer treated with lapatinib

1043

Background: Lapatinib (LAP), a dual tyrosine kinase inhibitor (TKI), is effective in the treatment of HER-2-positive metastatic breast cancer. Liver toxicity has been reported as a side effect of several TKIs. We analyzed the liver safety of LAP using available data from 16 metastatic cancer trials. Methods: LAP (as monotherapy or in combination) was administered to 2,968 patients (pts) in metastatic cancer trials. Liver function tests were prospectively evaluated. We defined liver toxicity events as either NCI CTCAE grade (Gr) 3 or 4 alanine and aspartate aminotransaminases (ALT/AST) or meeting Hy's Law criteria (liver injury with jaundice). Results: Overall Gr 3 and 4 ALT/AST events were seen in 45/2,968 (1.5%) and 2/2,968 (0.07%) pts, respectively. Of LAP monotherapy pts, Gr 3 and 4 ALT/AST was seen in 13/1,470 (0.9%) and 1/1,470 (0.07%), respectively. Of LAP + monoclonal antibody (mAb) pts (trastuzumab or bevacizumab), Gr 3 and 4 ALT/AST was seen in 2/199 (1.0%) and 1/199 (0.5%), respectively. Ten of 645 pts (1.6%) treated with LAP + chemotherapy (capecitabine or paclitaxel) had Gr 3 ALT/AST. Twenty of 654 pts (3%) treated with LAP + letrozole had Gr 3 ALT/AST. Among 2,968 pts, Hy's law toxicity occurred in 8 (0.3%) pts: 2/1,470 (0.14%) pts treated with LAP alone, 1/199 (0.5%) pts treated with LAP + mAb, 4/645 (0.6%) pts treated with LAP + chemotherapy, and 1/654 (0.2%) pts treated with LAP + letrozole. Alternative causes of liver toxicity such as metastatic liver disease, infectious hepatitis, and heart failure will be reported at the meeting. Conclusions: Review of data from 16 clinical trials in metastatic cancer revealed low levels of liver toxicity for LAP. Oncologists should be vigilant for this rare side effect of LAP. A proposed monitoring algorithm of symptom assessment and frequency of hepatobiliary laboratory monitoring will be shown.

[Table: see text]

Cardiac safety in patients (pts) with metastatic breast cancer (MBC) treated with lapatinib (L) and trastuzumab (TRA)

514

Background: Clearly defined standards for assessing cardiac toxicity do not exist for newer agents used as treatment for BC, e.g., tyrosine kinase inhibitors. To evaluate the usefulness of increased cardiac monitoring and cardiac function (LVEF) in pts treated with L+TRA, data from 4 trials were analyzed. Methods: From July 2003 to Dec 2006, 238 pts received L+TRA (n=203) or L+TRA with paclitaxel or docetaxel (n=35) for HER2-positive MBC. LVEF was evaluated at screening, every 8 weeks after starting L+TRA, and at withdrawal via multiple-gated acquisition scans or echocardiograms. Rate of symptomatic cardiac events (CE; NCI CTCAE Grade 3 or 4 LV systolic dysfunction) or asymptomatic LVEF decreases (=20% relative to baseline and below the institution’s lower limit of normal) were assessed. Results: None of the 238 pts had a symptomatic CE. Four pts had a single asymptomatic LVEF decrease and 1 pt had 2 asymptomatic LVEF decreases, totaling 6 decreases in 5 (2.1%) pts. These pts were women aged 36–64 years and had previously received anthracyclines (A; n=2), A+TRA (n=2), or unknown therapy (n=1). Median time to onset of LVEF decrease was 83 days; all but 1 decrease occurred within 75 days after initiating L+TRA (range: 18–221 days). Baseline LVEFs of 62%, 60%, 62%, 74% and 58% decreased to 47%, 46%, 45%, 45%, and 45%, respectively. L+TRA was temporarily interrupted in 3 pts and continued in 2 pts despite LVEF decrease. Per investigators, LVEF decrease resolved with no further sequelae in 4 pts (59%, 56%, 60%, and 50%) and was ongoing in 1 pt. Conclusion: Initial data indicate L+TRA or L+TRA with taxanes does not constitute a serious incremental cardiac risk and may not require more stringent cardiac monitoring than is used for A or TRA alone. The combined effect of HER2 inhibition with L+TRA appears not to increase the risk of CE in this population.

No significant financial relationships to disclose.

Treatment of polymorphous light eruption with nicotinamide: a pilot study

In a pilot study, 42 patients suffering from polymorphous light eruption (PLE) were treated with oral nicotinamide, 3 g daily, for 2 weeks. Twenty-five patients remained free from lesions despite extensive sun exposure. We suggest that an abnormality in tryptophan metabolism is important in the aetiology of PLE, and that nicotinamide administration partially corrects this.

Hepatitis A and B markers and presumable non-A, non-B hepatitis in a psychiatric institution

The frequencies of hepatitis A and hepatitis B markers were determined in 291 members of the staff and 714 patients of a psychiatric institution for adults. 71.8% of the patients suffered from psychosis, 17.7% from neurosis, and 10.6% from oligophrenia. 84.4% of the patients and 69.2% of the staff were anti-HAV-positive. - 26.8% of the patients and 19.9% of the staff showed at least one HBV marker. The frequency of anti-HBc increased with age but not with hospitalization. Anti-HBc-positive persons did not show transaminase abnormalities more often as reported previously. - 2.6% of the patients were presumable Non-A, Non-B hepatitis cases after excluding IgM-anti-HAV, IgM-anti-CMV or -EBV and possible toxic effects. The rate of presumable Non-A, Non-B hepatitis equaled the frequency of HBsAg-positive persons.